Learning from Failure in the Design Process: Experimenting with Materials [1 ed.] 1138919187, 9781138919181

Learning from Failure in the Design Process shows you that design work builds on lessons learned from failures to help y

351 117 606MB

English Pages 280 Year 2020

Report DMCA / Copyright

DOWNLOAD FILE

Polecaj historie

Learning from Failure in the Design Process: Experimenting with Materials [1 ed.]
 1138919187, 9781138919181

Table of contents :
Contents
Figures
Acknowledgements
Introduction
Chapter 1. Why Stretch?
Chapter 2. Why Cast?
Chapter 3. Why Carve?
Chapter 4. Why Stack?
Bibliography
Index

Citation preview

“Lisa Huang’s new book encourages a tactile exploration of building materials that is equal part experimentation and informed risk taking. Te text and images share how architects transform materials through stretching, casting, carving, and stacking in well-researched built examples and focused student investigations. By approaching failure, courageous design acts can reveal the synergy between technical construction techniques and aesthetic choices.” –Donna Kacmar, FAIA, Professor “Lisa Huang’s Learning from Failure in the Design Process looks at the verbs of building – stretching, casting, carving, and stacking – showing how these actions form common languages of process and form across centuries and continents. By parsing construction into these four provocative, inclusive categories, she fnds similarities between classic works of ancient architecture such as the Pantheon, modern icons like Scarpa’s Brion Cemetery, and contemporary structures like Allied Works’ Clyford Still Museum. Te result will be a helpful guide for students and a useful provocation for practitioners. Student work that builds on the lessons of these precedents will also be an inspiration to teachers seeking ways to bring building science to the desktop for their students. A remarkable, vital study, Huang’s book re-shapes the way we think about building and fabrication processes in design.” –Tomas Leslie, FAIA, Morrill Professor in Architecture, Iowa State University “Like a child learning to ride a bike and sometimes skinning a knee, an architect learns about materials, assemblies, construction processes, physics, weathering, and gravity all on the fy, while designing each building. Learning from Failure in the Design Process by Lisa Huang captures the magic that can happen when design thinking is applied to the technical aspects of materials and the making of architecture. Tis book will help even veteran architects rediscover their craft.” –Patrick Rand, FAIA, DPACSA, Distinguished Professor, NC State University “Examining an underappreciated aspect of architectural design, Huang reveals the essential connection between material innovation and experimental failure in the development of construction materials and methods. By exploring four fundamental methods of material assembly, and illustrating each section with both precedents from the history of modern building as well as full-scale constructions made by her students, Huang opens up productive paths for further experiments in material assemblies in both the academic and professional contexts, while also bringing to light new insights into the larger discipline of architecture.” –Robert McCarter, Ruth and Norman Moore Professor of Architecture, Washington University in St. Louis

Learning from Failure in the

Design Process

Learning from Failure in the Design Process shows you that design work builds on lessons learned from failures to help you relax your fear of making mistakes, so that you’re not paralyzed when faced with a task outside of your comfort zone. Working hands-on with building materials, such as concrete, sheet metal, and fabric, you will understand behaviors, processes, methods of assembly, and ways to evaluate your failures to achieve positive results. Trough material and assembly strategies of stretching, casting, carving, and stacking, this book uncovers the issues, problems, and failures confronted in student material experiments and examines built projects that addressed these issues with innovative and intelligent strategies. Highlighting numerous professional practice case studies with over 250 color images, this book will be ideal for students interested in materials and methods, and students of architecture in design studios. Lisa Huang is a practicing architect and assistant professor at the University of Florida School of Architecture, USA. She spent close to a decade working at Ofce dA in Boston. Lisa has been recognized with honors of the 2016 American Collegiate Schools of Architecture (ACSA)/American Institute of Architects Students (AIAS) New Faculty Teaching Award, and the 2017 Building Technology Educator Society (BTES) Emerging Faculty Award.

Learning from Failure in the Design Process Experimenting with Materials

Lisa Huang

First published 2020 by Routledge 52 Vanderbilt Avenue, New York, NY 10017 and by Routledge 2 Park Square, Milton Park, Abingdon, Oxon, OX14 4RN Routledge is an imprint of the Taylor & Francis Group, an informa business © 2020 Taylor & Francis Te right of Lisa Huang to be identifed as author of this work has been asserted by her in accordance with sections 77 and 78 of the Copyright, Designs and Patents Act 1988. All rights reserved. No part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers. Trademark notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identifcation and explanation without intent to infringe. Library of Congress Cataloging-in-Publication Data Names: Huang, Lisa, 1971- author.

Title: Learning from failure in the design process: experimenting with materials/

Lisa Huang.

Description: New York: Routledge, 2020. | Includes bibliographical references

and index.

Identifers: LCCN 2019050789 (print) | LCCN 2019050790 (ebook) |

ISBN 9781138919181 (hardback) | ISBN 9781138919211 (paperback) |

ISBN 9781315687971 (ebook)

Subjects: LCSH: Architectural design–Study and teaching. | Architectural

design–Case studies. | Building materials.

Classifcation: LCC NA2750 .H88 2020 (print) | LCC NA2750 (ebook) |

DDC 729–dc23

LC record available at https://lccn.loc.gov/2019050789

LC ebook record available at https://lccn.loc.gov/2019050790

ISBN: 978-1-138-91918-1 (hbk)

ISBN: 978-1-138-91921-1 (pbk)

ISBN: 978-1-315-68797-1 (ebk)

Typeset in Franklin Gothic and Garamond

by Deanta Global Publishing Services, Chennai, India

For the students, designers, and architects who never let the fear stop them from taking risks.

Contents

List of Figures Acknowledgements Introduction Chapter 1. Why Stretch? 1.1 What Can We Stretch? Material Considerations Typical Stretching Materials and Components Key Issues to Consider in Material Selection Notes

xii

xix

xx

3

3

3

9

9

1.2 How Do We Stretch? Typical Assembly Requirements Note

10

10

23

1.3 What Happens When Stretching? What Are the Failures/Limitations/Problems We May Encounter? Composite Assemblies: How Do We Integrate Rigid and Stretched Materials? Pliability and Sagging: How Do We Overcome the Efects of Gravity and Give

Dimension to Flatness and Floppiness? Alternative Strategies: How Else Can We Take Advantage of a Membrane’s

Natural Inclination to Cling and Drape? Lightness and Weight: How Do We Make a Typically Temporary Assembly

Look More Permanent? Stretching the Material Itself: How Can We Make a Rigid Material Look Soft

and Fluid? Note

24

24

24

33

36

42

51

58

ix

Contents

Chapter 2. Why Cast? 2.1 What Can We Cast? Material Considerations Typical Casting Materials and Components Atypical Casting Materials and Components Light-Transmitting Concrete: How Do We Make an Inherently

Opaque Material Transmit Light? Ultra-High-Performance Concrete: How Do We Compensate for

Weaknesses in Concrete? Air-Purifying Concrete: How Can a Building Material Contribute to

its Surrounding Environment? Key Issues to Consider in Material Selection Notes

61

61

64

76

76

77

80

81

81

2.2 How Do We Cast? Typical Assembly Requirements Key Steps in the Casting Process Mixing Casting Ingredients Assembling Formwork and Its Structural Support Assembling an Internal Reinforcing Structure Applying Releasing Agent Vibrating the Mix Removing Formwork and Treating Surfaces Atypical Formwork Strategies

82

82

82

82

83

84

84

85

85

87

2.3 What Happens When Casting? What Are the Failures/Limitations/Problems We May Encounter? Precision and Control: How Do We Accommodate or Outsmart Inevitable

Inconsistencies in the Casting Process? Texture and Unpredictability: How Do We Turn Surface Inconsistencies or

Defects into Design Features? Texture and Exactitude: How Do We Make A Rough Material Look

More Refned? Form and Lightness: How Tin Can We Cast a Material? Plasticity and Mass: How Else Can We Highlight the Fluidity of a

Cast Material? Notes

94

94

Chapter 3. Why Carve? 3.1 What Can We Carve? Typical Carving Materials and Components Scale of the Building Scale of the Component Key Issues to Consider in Material Selection

x

97

112

119

125

134

140

143

143

143

150

152

Contents

3.2 How Do We Carve? Typical Assembly Requirements

154

154

3.3 What Happens When Carving? What Are the Failures/Limitations/Problems We May Encounter? Operation and Composition: How Do We Make Something Predictable Look

Unpredictable? Ornamentation and Stability: How Do We Maintain and Express Structural

Integrity in Carving?

155

155

158

162

Chapter 4. Why Stack? 4.1 What Can We Stack? Typical Stacked Materials and Components Atypical Stacking Materials and Components Key Issues to Consider in Material Selection Note

171

172

183

187

189

4.2 How Do We Stack? Typical Assembly Requirements Historical Shift from Bearing Wall to Veneer Cladding

190

190

191

4.3 What Happens When Stacking? What Are the Failures/Limitations/Problems We May Encounter? Lateral Stability and Height: How Do We Increase the Height of an Assembly

of Small Modules While Keeping It from Overturning? Lateral Stability and Height: How Do We Make a Fluid Form Out of

Something Rigid? Pattern and Texture: How Can We Use the Individual Module to Contribute

to a Dynamic Collective for the Uniform Monolith? Porosity and Lightness: How Do We Transmit Light through a

Stacked Assembly? Mass and Lightness: How Do We Make Something Inherently

Heavy Defy Its Own Weight? Notes

193

193

Bibliography Index

196

200

205

219

231

238

239

247

xi

Figures

0.1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.22 1.23 1.24 1.25 1.26 1.27 1.28 1.29 1.30 1.31

xii

Windows with a subtle brick arch at the Phillips Exeter Library. Nomadic tents using fexible materials. Hajj Airport in Jeddah, Skidmore. Denver International Airport. ETFE facades, Allianz Arena, and MediaTIC. ETFE foil details at MediaTIC. Munich Olympics Stadium cable net and panels. Façade of Media-TIC at the public sidewalk. Structure at Temps Nouveau Pavilion. Interior of the Temps Nouveau Pavilion. Lilas Pavilion for the Serpentine Gallery. Burnham Pavilion fabric stretched between aluminum trusses. Section drawings of the Burnham Pavilion. Interior view of the Burnham Pavilion. London Olympics Basketball Arena aerial view. London Olympics Basketball Arena façade surface. Building-scale membrane at the London Olympics Shooting Gallery. Roof assembly at the London Olympics Shooting Gallery. Structural support at the façade. Mechanical connection at MediaTIC ETFE cushion. Joint between ETFE cushions at the Allianz Arena. Wall assembly detail at the Watercube. Infating Kengo Kuma’s Tee Haus pavilion. Interior of infated Tee Haus pavilion. Aerial view of the Ark Nova. Ark Nova before infation. Interior view of Ark Nova performance space. Exterior view of the completed Phillips Pavilion. Cast-in-place concrete ribs and construction of Phillips Pavilion. Construction of the Healy House Steinmetz. Workers spraying on Cocoon plastic. Welder installing steel straps for the Healy House roof.

xxii 4

5

6

7

7

8

9

11

12

13

13

14

15

15

16

16

17

17

18

19

20

20

21

21

22

22

25

26

26

27

28

Figures

1.32 1.33 1.34 1.35 1.36 1.37 1.38 1.39 1.40 1.41 1.42 1.43 1.44 1.45 1.46 1.47 1.48 1.49 1.50 1.51 1.52 1.53 1.54 1.55 1.56 1.57 1.58 1.59 1.60 1.61 1.62 1.63 1.64 1.65 1.66 1.67 1.68 1.69 1.70 1.71 1.72 1.73 1.74 1.75 2.1 2.2 2.3 2.4 2.5

China Academy of the Arts, tiled roofs and roof tile façade screen. Façade screen detail at the China Academy of the Arts. Natural light transmitted through the façade. Preliminary material tests in framing and stretching fabric. Detail of the fabric at a rectangular aperture. Final assembly and original conceptual drawing. 2014 Venice Biennale Kinetic Wall by Barkow Leibinger. 2015 Serpentine Pavilion by SelgasCano. Unilever Haus with outer façade layer of ETFE. Partial façade and a close up of the frame. Detail of the cable and ETFE assembly. Partial elevation of the Steilneset Memorial. Exterior and interior detail at the connection between fabric and steel cables. Spiral stair in the Hinman Building. Detail between stainless-steel net and structure. Blueprint installation illuminated at night. Tree-dimensional surface of the Blueprint installation. Chainmail draped over Kukje Gallery building volumes. Detail of connection at top of the chainmail screen. Detail of the chainmail draped at the entry. Tubaloon infated and anchored. Tubaloon during installation. Serpentine Sackler Gallery. Roof edge detail at Serpentine Sackler Gallery. Section drawing of the roof edge. Te Serpentine Sackler Gallery roof under construction. Te Serpentine Sackler Gallery illuminated at night. Te roof assembly of the Center Pompidou-Metz interlocking with the

concrete building core. Layering of the woven wood structure with the PTFE membrane. Te roof illuminated at night. Test panel infated to the point of breaking. Composite images of the infated silicone panel prototypes. Final assembly of silicone panels opened and closed. New Museum by SANAA. Detail of the expanded metal panel façade at New Museum. Corner condition at the New Museum metal panels. Embossed copper façade panels at the de Young Museum. Metal façade at Messe Basel. Detail of façade with visible seams between each metal panel. Glass panels at Prada Aoyama by Herzog & de Meuron. Convex and concave glass in the Elbphilharmonie façade. Undulating windows at the Elbphilharmonie. Glass surface at the Vakko Fashion Center. Overall view of glass texture at the Vakko Fashion Center. Section drawing of the Pantheon. Cofered cast concrete dome at the Pantheon. Unity Temple concrete exterior. Guggenheim Museum under construction. Penguin pool at the London Zoo.

29

29

30

31

31

32

33

34

35

35

36

37

38

38

39

39

40

41

41

42

43

43

44

45

45

46

46

47

48

48

49

50

51

52

53

53

54

55

55

56

57

57

58

58

62

63

64

64

65

xiii

Figures

2.6 2.7 2.8 2.9 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 2.19 2.20 2.21 2.22 2.23 2.24 2.25 2.26 2.27 2.28 2.29 2.30 2.31 2.32 2.33 2.34 2.35 2.36 2.37 2.38 2.39 2.40 2.41 2.42 2.43 2.44 2.45 2.46 2.47 2.48 2.49 2.50 2.51

xiv

La Congiunta concrete volumes. Concrete detail at La Congiunta. Louisiana State Museum and Sports Hall of Fame exterior and interior. Louisiana State Museum and Sports Hall of Fame cast stone panel

installation. Plaster cast at Ini Ani. Crystal Palace cast iron structure. Bond Street façade with glass cladding and cast aluminum fence. Detail of cast glass and the cast aluminum. Hearst Ice Falls installation in the lobby of the Hearst Building. Cast glass block detail. Channel glass façade at the Nelson-Atkins Museum. Exterior view of the Seed Cathedral. Detail of the seeds cast into the acrylic rods. Studies of rotating fber optics in a concrete panel. Rotated image through the light-transmitting concrete panel. Translucent concrete panels at the Garden Smoking Pavilion. Ductal panels at MuCEM façade and roof. Pre-stressed footbridge at MuCEM. Pedestrian walkway between ductal panels and structural columns. Palazzo Italia with its air fltering concrete panels. Student mishaps in casting concrete. Te concrete volume inserted in Punta della Dogana. Teshima Art Museum used the topography as the concrete form. Interior space of the Teshima Art Museum. Concrete façade at the Voralberg Museum Addition. Detail of studs in the concrete. Palazzetto dello Sport interior of the concrete structure. Palazzetto dello Sport exterior. Construction of the roof using precast concrete panels. Rough edges of cast concrete from removing the formwork. Cold joint from pouring concrete on top of curing concrete. Cracks in the concrete at changes in concrete shape and thickness. Concrete texture at the Unite d’Habitation. Construction of the cast concrete formwork at Unite d’Habitation. Bush hammered cast concrete at Yale Art and Architecture building. Formwork and concrete casts during the construction of Yale Art and

Architecture building. Concrete façade with exposed aggregate at Schaulager. Concrete surface detail. Cast concrete façade of SOS Children’s Villages Lavezzorio

Community Center. Cold joint detail in the façade. Physical models of the cast concrete façade concept. Brion Cemetery chapel interior. Exterior detail of the ziggurat. Concrete surface displaying formwork traces. Detail of the wood form against dimensions of ziggurat. Bubbles cast on the surface of the concrete.

66

67

67

68

68

69

70

71

71

72

72

73

74

75

75

77

78

79

79

80

83

86

88

89

90

91

92

92

93

95

96

97

98

99

100

100

101

101

102

103

103

104

105

106

107

108

Figures

2.52 2.53 2.54 2.55 2.56 2.57 2.58 2.59 2.60 2.61 2.62 2.63 2.64 2.65 2.66 2.67 2.68 2.69 2.70 2.71 2.72 2.73 2.74 2.75 2.76 2.77 2.78 2.79 2.80 2.81 2.82 2.83 2.84 2.85 2.86 2.87 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13

Tiles embedded into the edge of cast concrete wall at Brion. Aluminum casting experiments in techniques. Initial tests of casting with ice. Light against the surface of the cast aluminum panel. Cast bronze façade of the American Folk Art Museum. Apertures in the façade. Detail of the cast bronze texture. Te interior surface of concrete in Bruder Klaus Chapel. Te exterior of Bruder Klaus and detail of rammed concrete. Formwork residue on the concrete. Concrete texture at Clyford Still Museum. Details of Clyford Still Museum concrete surface. Precast and glass façade of the Eberswalde Technical School Library. Detail of the pixelized image. TEA windows at exterior surface of concrete façade. TEA windows at interior surface of concrete façade. Volume of performance space tilts up to shape main entrance. Textured concrete walls inside the Konzerthaus Blaibach. Detail of the faceted interior concrete surface. Concrete screen difusing light into the Clyford Still Museum. Robert Maillart’s Cement Hall. Cosmic Rays Laboratory by Felix Candela. Tin concrete draped at the Portugal Pavilion. Detail of the joint between the concrete and the portico. Kresge Auditorium at MIT by Eero Saarinen. Close-up of the abutment and the roof. Ingalls Hockey Rink at Yale University by Eero Saarinen. Concrete arch and cables of Ingalls Hockey Rink during construction. TWA terminal aerial view. Cast concrete during construction of TWA terminal. Basento Bridge by Sergio Musmeci. Construction of the Rolex Learning Center. Te public space under and through the building. Exterior view of the stained glass window wall. Masonry construction before the application of sprayed concrete. Construction of the stained glass and concrete wall. Cappadocia. Te Treasury building at Petra. View into the Adalaj stepwell. Carved stone decorating the Adalaj stepwell. Panorama view of Matera’s sassi carved into the gorge. Sassi dwelling entrance. Section drawing of Casa Cava. Interior space of Casa Cava. Façade of Villa Vals. St Ignatius exterior of wood doors. Carving patterns at interior of wood doors. Villa Solaire wood enclosure. Close-up of the milled wood cladding.

109

110

111

111

113

114

115

116

116

117

118

119

120

121

122

122

123

124

125

126

126

128

129

130

131

132

133

133

134

134

135

136

136

138

139

139

144

145

146

146

147

147

148

149

149

151

152

153

153

xv

Figures

3.14 3.15 3.16 3.17 3.18 3.19 3.20 3.21 3.22 3.23 3.24 3.25 3.26 3.27 3.28 3.29 3.30 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 4.11 4.12 4.13 4.14 4.15 4.16 4.17 4.18 4.19 4.20 4.21 4.22 4.23 4.24 4.25 4.26 4.27 4.28

xvi

Drawing fles of wood topographies. Jig used while milling the wood board. Milled wood surfaces before sanding. Malta Valetta Parliament House by Renzo Piano

Building Workshop. Close-up of milled stone panels. Stone panels installation. Carved wood wall and bench at Tverrfellhytta. Section of the wood timber assembly. Interior view of the carved wall at Tverrfellhytta. SF MOMA façade. Typical Japanese wood joinery structures. Detail of Tamedia structure. Lobby at Tamedia Ofce Building. Wood façade of SunnyHills. SunnyHills wood structure detail. Sean Collier Memorial at MIT by Höweler + Yoon. Collier Memorial stone cut with precision. Pyramid at Djoser. Stone quarry. Stone façade at Ohel Jakob Synagogue. Adobe bricks drying in Chiapas Mexico. Great Mosque at Djenné in central Mali. Baker House facade with intermittent clinker bricks. Close-up of clinker brick at Baker House. MIT Chapel interior masonry wall. MIT Chapel exterior masonry wall. Overall façade of CMU modules stacked. Detail of concrete panels at Ennis House. Glass lens façade at Maison de Verre. Close-up of the glass lens. Glass block façade at Maison Hermes. Glass blocks at the edge and corner of Maison Hermes. Cordwood masonry construction at Arcus Center for Social

Justice Leadership. Shifted cordwood modules to form windows. Reclaimed building materials in the Ningbo Historic

Museum facades. Details of the stacked facade assembly. Photo: Xuancheng Zhu. Interior walls composed of stacked roof tiles created at Matadero

Warehouse 8B. Details of roof tile assembly. Lucy Carpet House by Rural Studio. Cardboard Bale House by Rural Studio. Young Vic Teater brick façade texture. Kiln for fring bricks in Chiapas Mexico. Original stacked assembly proposal. Attempt at assembly.

156

157

157

159

159

160

160

161

161

163

164

165

166

167

167

168

168

172

172

173

174

174

176

176

177

177

178

179

180

181

181

182

183

183

184

184

185

186

187

188

188

189

190

194

195

Figures

4.29 4.30 4.31 4.32 4.33 4.34 4.35 4.36 4.37 4.38 4.39 4.40 4.41 4.42 4.43 4.44 4.45 4.46 4.47 4.48 4.49 4.50 4.51 4.52 4.53 4.54 4.55 4.56 4.57 4.58 4.59 4.60 4.61 4.62 4.63 4.64 4.65 4.66 4.67 4.68 4.69 4.70 4.71 4.72 4.73 4.74 4.75

Photo: Cervin Robinson, Monadnock Building in Chicago. Monadnock longitudinal section drawing with dimension changes in

load-bearing masonry walls. Stacked stone façade at Chokkura Plaza. Stone modules transitioning from opaque to screen. Steel frame supporting the stone modules. University of Virginia serpentine garden walls. Gramazio Kohler Structural Oscillations. Entrance façade to the Church of Christ the Worker. Ruled surface of the brick walls. Interior of the Church of Christ the Worker with undulating roof. Tin stacked veneer screen at church entry. Rose window at the San Pedro Church. Stacked facade of Aalto’s studio and house. Detail of the diferent brick patterns. Mortar joints as fgures in Lewerentz’s St Petri Church. Te four light cannons with alternating brick patterns. Brick pattern designating chair locations. Window detail at St Petri Church. Curved wall detail at Tongxian Gatehouse. Building cantilevering over the road. Main entry into the Tongxian Gatehouse. Brick pattern turning the building corner. Dynamic facade of the South Asian Human Rights

Documentation Center. Oblique view emphasizing movement in the surface. Drawing of the stacking proposal. Tests to bind the stacked bricks. Final stacked assembly. Privacy screen at the Brick Weave House façade. Rotated bricks in the interior wall of Dude Cigar Bar. View through the rotated brick screen. Details of Laurie Baker’s stacked brick structures. Stacked stone exterior of Kolumba Museum. Light that transmits through the stacked stone wall. Stacked lumber creating partition walls for the Swiss Sound Box Pavilion. Brick wall pattern at the Brick Pattern House. Brick Pattern House textured façade. Construction process at the Brick Pattern House. Window detail of brick facade. House in a Green Neighborhood brick assembly detail. Brick façade at House in a Green Neighborhood. 40 Knots House brick screen facade. Weaving bricks at the 40 Knots House. Drawing proposal of stacking patterns. Stacked modules in a self-supporting pattern. Brick façade of the Casa de Ladrillos. Casa de Ladrillos detail of two wythes in the three-dimensional assembly. Structural form of the Yusuhara Wooden Bridge Museum.

196

197

198

199

199

200

201

202

202

203

204

205

206

207

208

209

210

210

212

213

213

214

215

216

217

218

219

220

220

221

221

222

222

223

224

225

226

227

228

228

229

229

230

231

233

234

234

xvii

Figures

4.76 4.77 4.78 4.79 4.80

xviii

Detail of the stacked LVL girders. Lions Scout Hut, uses thinnings as ballast. Rural studio’s testing ground for full-scale mock-ups. Stacked timber composing the Final Wooden House. Interior spaces defned by the stacked timber.

235 235 236 237 237

Acknowledgements

I immensely admire the architects and designers included in this book for producing inspirational architecture with material assemblies and for challenging conventions with their thought-provoking contributions. As an educator, I am grateful that these professional works are available as examples of innovative design thinking. Te student experiments in the book were produced between 2014 and 2017 by wonderful risktakers in graduate and undergraduate level architecture courses and many other material experiments could have been chosen. Special thanks and appreciation to the architects and designers featured in this book for recognizing the value of this topic in architecture education and for being unafraid of the book title. I deeply appreciate working with fearless students and generous colleagues at the University of Florida School of Architecture. Tis book is a tribute to my graduate and undergraduate students whose enthusiasm, dedication, and talents are unparalleled. Tey gave me joy and inspiration and they will always have my respect and admiration. I am indebted to Nina Hofer, Kathryn Dean, Jason Alread, Charlie Hailey, Bradley Walters, and Alfonso Perez-Mendez for their feedback, support, and sage advice during the development of this book. Tey were invaluable in shaping the structure and in pushing me to strengthen my work. I am overwhelmingly thankful for the tremendous education, mentorship, and experience working with Monica Ponce de Leon and Nader Tehrani at Ofce dA. Tank you to my family and friends for their humor and continued belief. Tanks to Volta and Curia for providing ideal spaces for thinking and concentrating.

xix

Introduction

Tis book is not a treatise on construction. It is, instead, a collection of practical thoughts intended to bridge the gap between abstract technical knowledge and design thinking in action. Tis is not a technical manual attempting to cover materials and assemblies compre­ hensively. Rather, we will consider material examples from an applied design perspective, discussing potential alliances and assemblies. By presenting materials through the lens of their applications and coalitions, we will think of the problems encountered in assemblies as opportunities for invention. Te types of questions that interest us here include, what is the potential of a building material? What is that material’s impact on design? How do assembly methods infuence design ideas and design logic? What are the architectural implications of these assembly systems and materials? In the design process, we cannot think of materials as easily interchangeable, as each certainly has intrinsic rules. We cannot replace brick for metal without a signifcant rethinking of the assembly method and process of working with the material. A change in material not only alters the aesthetic appearance but also the tectonic composition. Tis does not mean, however, that standards of construction are preconceived; we believe that any previous knowledge that we have about a particular material should never limit its future design potential. As architects and designers, we should understand construction conventions, but also always explore new techniques that expand conventional construc­ tion thinking. Our goal here for architectural design is not just aesthetics. We predicate “Design” as an experimental practice of existential discovery. In this book, we will focus on questions that challenge the potential of materials and the ways of working with them. We conceive our work in this book as the presentation of a method for experimentation. One that, in cel­ ebrating innovation, focuses on and builds upon the inevitable failures intrinsic to all design processes that break new ground.

xx

Introduction

The Value of Experimentation and Taking Risks You say to a brick, “What do you want, brick?” And brick says to you, “I like an arch.” –Louis Kahn We often understand Louis Kahn’s well-known quote as a call to recognize and accommodate the inherent qualities of a material. Using it for his architectural classes, Kahn frequently repeated his brick dialog in many variations. More often than not, however, the best-known part of the quote – introduced above – was only the beginning of his theatrical conversation. Kahn then frequently said to brick, “Look, I want one arch too, but arches are expensive and I can use a concrete lintel.” In further examining the question, Kahn was also undoubtedly opening the range of results. In doing so, he promoted alliances, innovation, and experimen­ tation in working with materials. In Kahn’s thoughts, even a common, ordinary brick wants to be something more than it is. It aspires to be something better than it is. Te brick does not want economical, practical, or aesthetic constraints to limit its potential. Tis aspiration of the material to be something better implies entering into the unexpected and, as in the rethinking of an opening in the form of a structural arch, the recognition of the need to take calculated risks during the process of design. Visual and functional conventions or preconceptions never limited Kahn’s think­ ing. At a quick glance, the brick façade and openings of his Phillips Exeter Library may not seem unusual. However, upon closer inspection, Kahn is clearly challenging the potential of the brick. As we know, there is a structural logic to the curvature of the arch in distributing structural loads. However, at Exeter Library, Kahn minimizes the curvature of the arch to the point that it is essentially fat. Instead of using a monolithic lintel of concrete or steel, the bricks assemble to produce a fattened arch that spans the top of the window openings (Figure 0.1). Kahn transforms a brick arch into a brick lintel. Te ends of the fattened arch transfer structural loads down along the vertical edges of the opening below, so each window above is able to increase its opening width. Kahn’s subtle alliance between bricks and other materials greatly extended the material’s range of possibilities.

Risk and Professional Practice As designers, we are concerned with the form, aesthetics, and spatial experiences within our buildings. As full-fedged architects, however, we must also be concerned with detailing the assembly, coordinating the design team, maintaining budgets, and prioritizing life safety. Te failure to protect the health and welfare of the building occupants looms over every architect. Failures – water leakage, thermal discomfort, excessive costs – in building design and assem­ bly all can lead to grave health issues and later potential lawsuits. We simply cannot risk the lives of others, so we are very conscientious of protecting occupants and minimizing risks in how we compose materials in our building design. Because of these natural fears, there is a

xxi

Introduction

FIGURE 0.1 Windows with a subtle brick arch at the Phillips Exeter Library. Photo: Zachary Wignall.

tendency to fall back on material and construction conventions and standards, dictated by a construction industry frequently reluctant to any kind of risk-taking. We often forget, how­ ever, that steps in the design process are not meant to be fnal, and that while on the journey of design, it is important to keep our eyes open to see potential innovations.

Risk and the Design Process Architecture is more than buildings. In a broader sense, architecture is the activity of think­ ing buildings, and therefore it includes a process that starts from the inception of design ideas. Often, we idealize the architecture design process as the quintessentially performative napkin sketch. However, buildings rarely emerge from these kinds of quick ideas. Even when they do, rarely does a sketch translate directly into the physicality of a building. In most cases, there are numerous steps and transformations between the initial idea and the built reality. As part of the process, we need to test our conceptual ideas through physical incarna­ tions. Trough that contact with materials, ideas are constantly being reworked and refned.

xxii

Introduction

As  we  will attempt to illustrate in this book, essentially, the process of developing archi­ tectural ideas is iterative and it inherently revolves around recognizing what is wrong with our successive attempts. Tat is, learning from failure. If an idea does not work, we make adjustments that respond accordingly. Architecture evolves and advances with each iteration. Design is about exploring a range of possible solutions and being unafraid to take risks and to be wrong within the confned environment of the process.

The Role of Failure in Understanding Materials Materials are the medium of architecture. However, most architects do not actually build their designs with their own hands. It is not often either, that architects experiment handson with materials in the design process. So, paradoxically, architects rarely engage directly with their real materials other than in the selection of samples. Many architecture educations do not include opportunities to engage in assembly using building materials at full scale. It seems obvious, however, that a direct engagement of materials cannot but enhance architec­ tural design. Te intention of this book is to address this gap. By proposing a methodology of direct and full engagement with materials both in the academy and in professional practice, we believe that the successive experiences encountered will create better architects. We believe that, without the need of being an expert craftsperson, successive experiences of working hands on with materials will develop an understanding of their realities. We can simulate it with either digital tools or scale models employing parallel materials, but reality at full scale always reveals new discoveries. However, our ultimate intention in proposing direct engage­ ment is that we believe it is the only method where we can bring materials to their physical and conceptual limits and in doing so test real failure. Tis book does not encourage that all architectural design should produce some­ thing never seen before. Architecture is a process that builds upon learning from other pro­ jects and precedents. Frequently, good buildings simply reawaken earlier moments of making truth. Tis is why, when looking at precedent case studies from professional practice, our interest will focus on their experimental and innovative methods of exploring materials, rather than on the visuals of their results. In thinking about materials and assemblies anew, in ways that will create inspired designs, it courts failure, a word that most avoid. In this book, however, we reclaim ‘failure’ as a concept that, inherent to them both, celebrates innovation and experimentation. Te engineer Henry Petroski (b. 1942) has a large body of research on failure in engineering designs. His research is critical in demonstrating the importance of failure in the design process and our work is indebted to him. His numerous books – pioneered by his best-selling To Engineer is Human: Te Role of Failure in Successful Design (1985) – examine case studies of failed projects and provide insight into the engineering thinking process. Unlike Petroski’s work, however, this book does not center on failed projects. Instead, we will focus on the role of taking risks in design process experimentation. We will look at inspiring projects that are the result of architects applying innovative methods and experiments. We will see how direct failure, and also attempts only initially considered as ‘failures,’ later became new discoveries starring as defning design features.

xxiii

Introduction

Thinking and Designing with Materials Material Behavior It is important for us to acknowledge that each individual material has a defned personal­ ity with specifc characteristics and traits defned in interaction both with both reality and other materials. When we design on paper or digitally, materials are inert and defy gravity. Tey exist in a neutral and idealized context where they cannot express themselves. Even the same material does not always behave in the same way. In actuality, the environment and weathering actively afect its behavior. Termal expansion and contraction, reaction to water, erosion and deterioration demonstrate that materials breathe and change with time and con­ text. When we think about materials only as surface applications to designs, we are wrongly assuming that they are all equal in characteristics and interchangeable. In doing so, we are simply neutralizing their personalities, and truly missing their design potential.

Selecting the ‘Right’ Materials Te choice of building material is not arbitrary and not all materials produce the same efect. While this is an obvious statement, our digital tools make it so easy and convenient to apply material patterns as surfaces added onto our volumetric conceptions that we may overlook the obvious. However, building materials are not like interchangeable wallpaper. Each material change afects not only the aesthetic appearance, but also the assembly techniques intrinsic to the full awareness of an architectural ensemble. If you exchange one material for another, dimensions, assembly compositions and construction strategies will also change. While select­ ing materials, we need to think about assembly procedures as recordings of human activity, and as such, intrinsic to the perception of the material. As this book will also demonstrate, real invention frequently comes not from the choice of material, but from the various ways to work with such material. Material design process always involves two steps, the identifcation of the desired aesthetic and architectural characteristics and the exploration of the various strategies to construct that efect. Troughout our architectural careers, we frequently learn more from the second than from the frst.

The Structure of This Book Often in architecture education, we learn about construction through successive lectures about each diferent material, considering their qualities and accepted assembly methods. Tis book attempts the next step, namely, how to apply the material knowledge emerging from survey courses into innovative design solutions. We will look at material knowledge through an alternative point of view, one that will emphasize the actions taken with or upon the materials during experimentation. Avoiding any attempt toward a comprehensive cataloging of possible engagement with materials, we will use four operations, Stretching, Casting, Carving, and Stacking, as examples of the experimental method of inquiry that we propose.

xxiv

Introduction

Since the risk is always to reinvent the wheel, all experimentation and innovation must come out of the knowledge of – and desire of transcending – known conventions. In the need for understanding these typical building standards, each chapter frst briefy sets two questions relative to these operations. First, “What” kinds of materials frequently have we used for that operation? Second, “How” do we work with that particular action? Te remain­ ing portion of each chapter focuses on case-study experimentations and the questions and issues that emerge when pushing the potential of materials through the particular action or method. In this second portion, we will use student work to introduce limitations, problems, and failures that we usually encounter in the material operation. We will then survey profes­ sional built work that addresses these problems and in doing so produces an innovative and beautiful way of thinking about the issues. Tere are certainly overlaps that can occur between each of these operations and each in turn demands very diferent thinking processes. Stretching and casting both require methods including another material system – formworks, frames, external or internal struc­ tures – to shape the material. Even these coincidences lead to diferent approaches: in stretch­ ing, the formwork is an additive element providing structural supports, while in casting the formwork produces a negative to determine the material’s form. Carving implies the removal of material to create form, while stacking is the aggregation of a material to create a form. Tis book, however, does not attempt to categorize or cover every possible question or issue. While in any of the chapters we need to introduce its methodical infrastructure, what excites us – and ultimately motivated the book – are the case studies. Each built project featured undoubtedly has complex stories and details that may not be fully uncovered in this book. We will focus our attention on a visual understanding and analysis of these projects. In the end, we hope the reader will have a constellation of sparkling examples of how by taking describable risks with established methods, brilliant designers found innovative results.

xxv

Chapter 1

Why Stretch?

1.1

What Can We Stretch?

Material Considerations When we think of stretched materials in space-making, the most basic typology that emerges is the tent. It is one of the earliest primitive structures used for weather protection and domes­ tic enclosures. Nomadic peoples used animal hides or fabric held over a framework that could be easily assembled and disassembled as they moved from one location to another. Fabrics were draped, stretched, and held in tension to create a lightweight temporary shelter (Figure 1.1). Why would we consider using a stretched assembly as a design option? In modern times, we would utilize stretched assemblies for essentially the same reasons. If we need a quick temporary construction, stretching materials is efcient in covering large areas with a single membrane material. Its potential simplicity in construction enables a stretched assembly to be economical and lightweight. Stretching requires a thin pliant material and shaping the mate­ rial is dependent on the structural framework. Te material’s thinness can be both ethereal and vulnerable. Durability is the biggest concern for stretched assemblies. We need to design to resist tearing in the pliant material. Te panel shape, installation strategy, and framework connections are critical considerations to control the material’s behavior in a taut construction.

Typical Stretching Materials and Components In our discussion of stretched materials, we will consider the scale of the building and the scale of the component. At both these scales, a supple fabric or plastic membrane becomes a useful architectural material when something rigid – a structure or framework – gives it distinguishable form. Te stretched material has no rigidity until it is held in tension. At the component scale, stif materials like metals and glass can also be stretched and deformed to create three-dimensional panels. At the building scale, we would typically use a lightweight and thin fabric or plastic membrane as a single material component to span long distances. Te foppy material needs to be pulled taut in order to create a stable structural form. Precise cuts and patterns

3

Why Stretch?

FIGURE 1.1 Nomadic tents using fexible materials. Photo: Richard Throssell.

for the material minimize wrinkles in the stretched assembly. As with most building compo­ nents, stretched materials come in limited dimensions, so we weld or sew together membranes to create larger components. Most stretched materials at the building scale take advantage of translucency and light transmitting characteristics of the membrane. However, seams are vis­ ible from the interior during the day and visible from the exterior when illuminated at night, so we also must consider the design of the seaming pattern. In early experiments with membranes, Frei Otto stretched fexible materials to explore the potential of the membrane in an assembly. Otto saw this fexibility as a strength not a weakness.1 A fexible membrane allowed a pure expression of structural forces and pro­ duced a new language of form and assembly to architectural structures. Stretched structures are commonly used for temporary open-air pavilions at expositions to test the fexible material’s potential. Te development and evolution of tensile structures transform stretched materials into airtight and watertight assemblies. Permanent buildings using stretched membranes are monolithic, but they also refect a temporary and ephemeral appearance. Coated fabrics as stretched architectural membranes include woven fberglass, polyester, nylon, or polyethylene. Durability of the membrane is the primary concern, so the sturdy fabrics and plastics used for sails were precursors for building components. Tese

4

What Can We Stretch?

woven membranes are coated with PVC, Tefon (PTFE), or silicone to help increase longevity and easy maintenance. In addition, the coating provides an airtight and water-resistant UV protectant for the membrane. It needs to withstand wear and tear from temperature changes, weather impacts, and UV exposure. Woven textile materials may also have inherent elasticity and ofer a range of opacities and translucencies. Stretched fabric options vary in fexibility, life span, code compliance, light transmission, tear strength, and durability. Te choice of fabric depends on its application and the architectural characteristics needed for the mem­ brane. Material costs vary and the combination of fabric and coating infuences its suitability for an assembly. Coated fabrics can be singular components or stitched together into a monolithic panel. Te maximum dimensions of the fabric depend on the manufacturing equipment and production processes. Te width of a fabric panel is usually the limiting factor. In order to produce a monolithic membrane, the fabric components are joined together by welding or sewing. We must consider the pattern and cut of the fabric so that it coordinates with the supporting structure. Te fabric membrane also needs its own internal structure that pulls taut without jeopardizing the integrity of the membrane and seams. But with elastic fabric, we should also be aware of creep and sagging with time. Fabric panels will need reinforcement on its edges or corners and then also intermittent support to compensate for sagging. If the membrane is composed of fabric panels, the cutting, welding, or sewing together of the components is critical to ensure balance and stability when the membrane is pulled taut. In Skidmore, Owings and Merrill’s Hajj Terminal at the King Abdulaziz International Airport, fberglass fabric shades the facilities and spans a large area (Figure 1.2). Te use of fabric in a permanent building requires precision to ensure balance between the structure and the membrane. During construction, one of the fberglass fabric membranes was cut incorrectly, so when the membrane panel was installed, it put structural stresses

FIGURE 1.2 Hajj Airport in Jeddah, Skidmore, Owings & Merrill Photo: UR-SDV [GFDL (http:// www.gnu.org/copy­ left/fdl.html) or GFDL (http://www. gnu.org/copyleft/ fdl.html)].

5

Why Stretch?

in wrong places. As a result of the membrane’s tensile limitations, the fabric ripped in four places.2 Any imbalance of structural forces on the fabric can cause problems for the assembly. Fabric panel requires reinforced hems and grommets at edges and openings to pro­ tect fabric from tearing when it’s fastened to the structural anchors and supports. When illu­ minated at night, the fabric roof of the Denver International Airport by Fentress Architects reveals the hems and seams that unify the larger fabric membrane (Figure 1.3). Te hems negotiate between the fabric and the structural masts. Te fabric drapes from each peak revealing the orientation and structure of the seams. Tis seam pattern may seem like a small detail in the building, but it impacts our visual experience of the building and our under­ standing of the construction assembly. Te use of plastic sheets and Ethylene Tetrafuoroethylene (ETFE) foils in archi­ tectural constructions was originally developed by Dupont. Starting in the 1990s, these materials were introduced in European buildings. ETFE is a plastic polymer that is extruded into thin fexible sheets that resist deterioration and are recyclable. Te thin plastic membrane is very elastic and transmits light. It is an almost completely transparent material that is avail­ able in a range of colors and opacities. ETFE foil does not discolor or weaken structurally over time, so it withstands ultraviolet damage. To achieve solar glare protection, the foil surface can be tinted or overlaid with diferent surface patterns. ETFE foils utilize diferent assembly strategies compared to fabrics. Te thin foils are stretched by a cable net system or within a metal frame (typically aluminum) which is then inserted into a larger structure. Each panel can have a single layer or be multi-layered with two to fve foils. Te use of a metal frame supports the ETFE panel when it’s infated with air. Te infated cushion provides thermal insulation and its thermal properties increase with each additional layer of foil. As pioneering buildings that used ETFE foils, the facades of the Allianz Arena by Herzog & de Meuron and the Media-TIC building by Cloud 9 are paneled with ETFE cushions that mechanically regulate a constant air pressure within the cushion (Figure 1.4). Both projects apply fritted dot patterns as a solar flter on the ETFE

FIGURE 1.3 Denver International Airport, Fentress Architects. Photograph provided cour­ tesy of Denver International Airport.

6

What Can We Stretch?

FIGURE 1.4 ETFE facades, Allianz Arena, and MediaTIC. Photo: Lisa Huang.

foils. In the Media-TIC building, each ETFE cushion has three foils and the middle foil fuctuates to increase or decrease solar screening as needed (Figure 1.5). Sizes and dimensional limits of ETFE panels are dictated by wind and snow load requirements. Manufacturing processes establish the material dimensions with limited widths but much longer lengths in the other direction. An ETFE cushion with three or more foils is capable of achieving higher thermal resistance than glass. In addition, sensors are incorporated into each ETFE panel to monitor the air pressure and to adjust the cushion in the event of extreme pressure. ETFE is a product related to Tefon, so dirt and dust do not

FIGURE 1.5 ETFE foil details at MediaTIC. Photo: Lisa Huang.

7

Why Stretch?

stick to it. In terms of fre resistance, ETFE is a plastic, so the foil will melt at 500 degrees, but it will not drip as it melts. ETFE does not tear easily, but it is vulnerable to punctures. However, due to its typically panelized installation, ETFE cushions can be easily replaced. Steel cables of varying gauges and thicknesses can be stretched individually or fastened together into nets or meshes. Te spacing in steel cable nets is not as tight as in a fabric membrane, so for the steel net to be an enclosure, a secondary layer is needed to act as the weather barrier. Often, we use steel cables or nets to support other materials in a horizon­ tal or vertical enclosure. Steel cables at a larger scale have the beneft of also performing as structural members that support panels and membranes. To demonstrate the structural signifcance of stretched steel cable assemblies, we will examine two tent projects by Frei Otto, the Germany Pavilion at the 1967 Montreal Expo, and in collaboration with Günther Behnisch, the 1972 Munich Olympics Complex. Both projects use steel masts and fasten steel cables into a structural net. In the Germany Pavilion, the fabric weather barrier is hung below the structural net, while in the Munich Olympics Complex, rigid acrylic glass panels fasten to the structural net from above. In both projects, structural cables hang between masts and anchors at ground. Te Munich Olympics Complex is composed of permanent structures primarily for shade. To shed water, the framed and panelized glass sit on top of the steel net in a staggered pattern (Figure 1.6). Te Germany Pavilion for the Montreal Expo was a temporary structure, so it was more experimental. Steel cables 1/2-inch-thick were fastened together on site into a single net structure. Ticker cables were used at the edges of the net. Otto dimensioned the openings in the steel net so it could also function as a comfortable walking surface. Te steel cable net performs not only as the pavilion’s structure but also as the scafolding during construction. Te net’s dual function allowed the PVC-coated polyester fabric membrane to fasten approxi­ mately 12 inches below the net and relieved the enclosure fabric from structural stresses. Te cable net and the fabric stretched between seven steel masts and anchors to the ground. Te fabric transmitted natural light into the pavilion. However, the draping landscape of the steel cables and the fabric gathered snow in its low points.

FIGURE 1.6 Munich Olympics Stadium cable net and panels. Photo: © Jorge Royan / http:// www.royan.com. ar / CC BY-SA 3.0.

8

What Can We Stretch?

FIGURE 1.7 Façade of MediaTIC at the public sidewalk. Photo: Lisa Huang.

Key Issues to Consider in Material Selection Why would we select a stretched assembly? Most often, stretched materials appear in tem­ porary pavilions or structures because of their simplicity in the construction assembly. A stretched enclosure requires a minimal amount of building material which also minimizes project costs. Temporary stretched assemblies disassemble and reassemble with ease. In a permanent building component, stretching membranes simplifes the amount of materials layered in an assembly. Its light transmitting property is an advantageous characteristic; it allows us to produce an entirely translucent roof. As components of permanent buildings, we must evaluate the conditions that afect the stretched material’s durability and life span specifcally its exposure to sun, lateral forces of wind, and the efects of gravity over time. Any stretched material within reach is sus­ ceptible to the possibility of someone cutting or puncturing the membrane. For example, in both the Allianz Arena and the Media-TIC building, the ETFE cushions are elevated above the ground and out of reach from the base of the building (Figure 1.7).

Notes 1 2

Horst Berger, Light Structures, Structure of Light: Te Art and Engineering of Tensile Architecture, (Basel, Boston: Birkhäuser Verlag, 1996), 32. Ibid., 49–52.

9

How Do We Stretch?

Typical Assembly Requirements Before constructing any large-scale structures, Frei Otto experimented with stretched assem­ blies using models with representative materials such as soap bubbles, pantyhose, and meshes to fnd form. Otto was an admirer of Felix Candela’s work with thin concrete shells (we will later discuss Candela in the chapter on casting). So, Otto performed parallel research using thin fexible membranes.1 In the 1955 Federal Garden Exposition in Kassel Germany, Otto had the opportunity to test three diferent cotton fabric structures at full-scale. Te Music Pavilion was a 48-square-foot tent with a pair of opposite corners lifted up by tilted wood poles and the other two corners anchored to the ground. Te resulting saddle-shaped open-air tent was further stabilized by sewing steel cables into the hems of the tent fabric. Tis ensured that the structure would be stif and resist any lateral wind forces. Te second pavilion took the Music Pavilion one step further in geometric form by creating a butterfy wave-shaped tent. Two slanted structural posts with steel cables stretched between and supporting the fabric. Te third pavilion was a composition of three umbrella structures. Each umbrella had a circular wood frame and a double membrane cushion creat­ ing a mushroom form. Unlike an umbrella, Otto directed rainwater from an edge gutter to drain through the central structural post instead of along the umbrella edge. In the mush­ room pavilions, the fabric is wrapped around and secured to a frame. While in the other two tents, the tent forms are a result of the structural forces exerted on the fabric membranes. All three pavilions were illuminated to glow at night. We need two primary components in the installation of a stretched assembly – a membrane in tension and a structure to resist that tension. Whether we use single or multiple layers of membranes, the design of the structural system, the connection details, the fabrica­ tion process, and the installation are critical to the success of the stretched assembly. Te membrane is completely reliant on the structural strategy to give it shape and form. Tere needs to be structural balance between these components, so the structural components must be rigid to stretch the membrane in tension. In the process of form-fnding, the stretched assembly should be modeled and analyzed to achieve that balance and to uncover formal behaviors and potential problems. 10

1.2

How Do We Stretch?

As we discussed in Otto’s Music Pavilion at Kassel and the Germany Pavilion at the Montreal Expo, a hung or suspended assembly utilizes independent structural masts or posts that are held in place by cables. Te membrane is held taut at points or along its edges with the cables. It then creates a roofscape that drapes with gravity. Tis tent-like strategy is most often used for enclosures that do not need to be watertight like stadia and pavilions. Te structural calculations need to be precise to ensure that the posts, cables, and membranes are in balance. Te membrane will naturally drape but it should be tailored for tautness so that rain or snow does not add extra weight to the structure. If we stretch membranes from a central structural mast, the assembly takes on the efcient and familiar form of the circus tent. A membrane can be suspended into other forms depending on the structural confguration and how that structure compensates for the gravity efects. In the Temps Nouveau Pavilion at the 1937 Paris Expo, Le Corbusier and his cousin, Pierre Jeanneret, designed a temporary exhibit enclosure that was square in its plan but trapezoidal in its section. Jeanneret focused on the design of the pavilion enclosure while Corbusier focused on the design of the interior exhibit. Le Corbusier’s spiral organization of the exhibit required an interior height of two-story clear space. Te pavilion was designed to be easily dismantled and rebuilt. In order to achieve a uniform ceiling height, Jeanneret created a fat roof tent using two-story-tall structural pylons that tilted outward from the interior space (Figure 1.8). Guy wires helped to pull the pylons and prevent sagging or collapse in the structure. Te pavilion was a standard can­ vas enclosure. For the pylons, Jeanneret used modern three-dimensional steel trusses that tapered at its ends. On one set of opposing walls, the pylons tilt outward to stretch open the large canvas roof panel. Tere were seven pylons on each pavilion edge and horizontal girts spanned between each pylon at ground, midpoint, and roof. Steel cables cross braced between the pylons.

FIGURE 1.8 Structure at Temps Nouveau Pavilion. Photo: Albin Salaün © F.L.C. / Adagp, Paris, 2019 sauf pour l’église de Firminy:© F.L.C. / ADAGP, Paris [année/year] et José Oubrerie [Conception, Le Corbusier architecte, José Oubrerie assistant (1960–1965). Réalisation, José Oubrerie architecte (1970–2006)] et pour la Chapelle Notre Dame du Haut à Ronchamp: © ADAGP, Paris [année/year].

11

Why Stretch?

Te canvas fabric was fastened to the inner edge of the steel structure. Before the Temps Nouveau, Jeanneret had been working on projects and experiments with canvas at diferent scales from the house to the stadium. For the Temps Nouveau, Jeanneret and Le Corbusier proposed using a non­ combustible transparent plastic sheet (cellulose acetate), but the material was too expensive. Canvas was lighter and more fexible. Tis roof membrane suspended from the steel cables that stretched between the pylons. Canvas for the pavilion’s vertical walls hung of the horizontal girt of the pylons. Te trapezoidal shape of the interior space was determined by the tension in the roof suspension cables that then supported the hung roof membrane. Since the fabric was attached at points along the cables, the fabric was not fully taut because the membrane naturally sags with weight and gravity (Figure 1.9). Framed assemblies stretch membranes over a rigid structure that resists tension generated in the material. Te membrane should be tailored to shape and hemmed on its edges to fasten to the frame and to keep the membrane taut. Te frame establishes not only struc­ tural integrity in the assembly, but it also defnes three-dimensional form for the membrane. Two pavilions by Zaha Hadid Architects, Lilas for the Serpentine Gallery and the Burnham Pavilion in Chicago, both created distinct formal geometries with fabric mem­ branes stretched over structural frames. Hadid’s Lilas is reminiscent of Otto’s three umbrella pavilions at Kassel (Figure 1.10). Unlike Otto’s pavilions, the fabric used for Lilas mediated between the verticality of the structural post and the horizontality of the umbrella. Te PVC fabric in each umbrella was a single tailored membrane fastened between the top edge of the steel frame and the base of the structural support post. Te membrane narrowed in at the column to shape the space underneath the umbrella. Te fabric was cut into panels that were narrow at the bottom and widened to the edge of the umbrella. Te fabric panels were welded together to create a continuous membrane without fasteners exposed on the surface. Te structure and assembly of the three Lilas umbrellas were identical in geometry and form. Te structure was a steel tube post with steel frames branching out to support a continuous steel tube. Te shape of the umbrella was asymmetrical with a tilted diamond steel frame at the top and at the base. Te diamond-shaped canopy was 47 feet long × 29.5 feet wide. A smaller scale steel tube interlocked with the PVC fabric and also stretched the fabric into its corseted form. In plan, these three diamond-shaped umbrellas nested together and rotated 120-degrees from each other creating dynamic views of the pavilion from any viewpoint. Tis cleverly and efciently gave the illusion that the umbrellas were each difer­ ent in form. In Zaha Hadid’s Burnham Pavilion, bent aluminum tubes created a framework of trusses that were parallel to each other creating a cocoon-shaped ribbed structure. Strips of PVC fabric stretched between trusses above and below the framework. Since this was a temporary pavilion, zip-ties connected the fabric panels to the aluminum frame. Te exterior and interior membranes hid the aluminum structure, but the organization and rhythm of the framework were expressed in the fabric surface of the pavilion (Figure 1.11). Te Burnham Pavilion’s exterior membrane was a polyester cotton blend with an acrylic topcoat. Tis fabric does not have inherent elasticity, so the fabric had to be cut

12

FIGURE 1.9 Interior of the Temps Nouveau Pavilion. Photo: Albin Salaün © F.L.C. / Adagp, Paris, 2019 sauf pour l’église de Firminy:© F.L.C. / ADAGP, Paris [année/year] et José Oubrerie [Conception, Le Corbusier architecte, José Oubrerie assistant (1960–1965). Réalisation, José Oubrerie architecte (1970–2006)] et pour la Chapelle Notre Dame du Haut à Ronchamp: © ADAGP, Paris [année/year].

How Do We Stretch?

FIGURE 1.10 Lilas Pavilion for the Serpentine Gallery. Photo: Luke Hayes, Courtesy of Zaha Hadid Architects.

FIGURE 1.11 Burnham Pavilion fabric stretched between aluminum trusses. Photo: Edward Stojakovic from Portland, OR, United States [CC BY 2.0 (https:// creativecommons. org/licenses/by /2.0)].

precisely to a pattern so that membranes were taut. Te interior membrane was larger woven polyester fabric panels tailored to create concave curves in the interior space. Te exterior membrane stretched strips of fabric from one structural truss to the next truss. Te interior membrane was composed of three large sheets – two for the walls and one for the ceiling. Fabric segments were sealed together to make one sheet. Te assembly strategy for stretching fabric difered between the exterior and interior. On the exterior, the membrane stretched between pairs of trusses. Te faceting of the fabric panels generated the pavilion’s curved form. On the interior, the membrane was cut to shape the space. Pockets were sewn into

13

Why Stretch?

FIGURE 1.12 Section drawings of the Burnham Pavilion. Photo: Courtesy of Zaha Hadid Architects.

the back of the fabric using the overlapping seams. Te tube frame slid through the interior membrane to secure it to the structure. Between each truss, the membrane sliced open at the roof to form apertures bringing in natural light and expressing the thickness of the assembly (Figure 1.12). Te space between the exterior and the interior membrane varied in dimension throughout the pavilion. At each roof opening, the fabric had to mediate between the geom­ etry of the exterior and interior forms. Tis required even more precision in the cutting and pattern of the stretched membrane in order to avoid wrinkles in the assembly (Figure 1.13). A pair of buildings from the 2012 Olympics in London, the Basketball Arena by Sinclair Knight Merz and the Shooting Galleries by Magma Architects, also provided examples of the potential in framed stretched assemblies. Both buildings were envisioned as structures that could be disassembled and reused in new locations. Both also used recy­ clable translucent PVC membranes stretched over prefabricated steel structures. Te use of stretched membranes and prefabrication allowed for quick construction processes. Te façade of the Basketball Arena was organized into vertical fabric segments stretched between the structure from base to roof. Trussed columns supported each vertical module of prefabricated steel frames. Tese steel modules allowed the building to be con­ verted into diferent sizes in the future. A series of steel arches spanned between each verti­ cal module to prevent structural racking within the prefabricated module. Te steel arches protruded from the face of the structure and each arch was staggered to create a textured pattern on the building façade (Figure 1.14). Te façade cladding was installed with 100 feet high by 24 feet wide strips of PVC fabric. Each PVC panel was fastened at the edges of the vertical framework module. It was tightly stretched over each vertical module, so the arched ribs pushed on the membrane. Te stretched fabric took on the shape of the framework. During the day, the translucent façade transmitted natural light into the building and also

14

How Do We Stretch?

FIGURE 1.13 Interior view of the Burnham Pavilion. Photo: Roland Halbe.

FIGURE 1.14 London Olympics Basketball Arena aerial view. EG Focus [CC BY 2.0 (https://creati vecommons.org/l icenses/by/2.0)].

expressed a three-dimensional surface that constantly changed as it captured light and shad­ ows (Figure 1.15). At night, artifcial light projected through the PVC membrane to reinforce the building’s dynamic appearance. Like the Basketball Arena, the façade membranes of the three Olympics Shooting Gallery buildings are stretched by a structural framework to create a three-dimensional façade (Figure 1.16). In the Shooting Gallery, the structure is a system of trussed beams and columns with cantilevered stand-ofs that connected to the membrane. Te exterior and inte­ rior membranes were installed as a singular sheet of translucent fabric composed of welded

15

Why Stretch?

FIGURE 1.15 London Olympics Basketball Arena façade surface. The Department for Culture, Media and Sport (https:// www.fickr.com/p eople/49429730@ N08).

FIGURE 1.16 Building-scale membrane at the London Olympics Shooting Gallery. Photo: Hufton & Crow, Courtesy of MAGMA Architecture.

PVC membrane panels. Te building’s steel structure was concealed by two membranes on either side of the framework (Figure 1.17). Large-scale circular steel frames are supported by the steel structure and interlocked the membrane. As a result, the three-dimensional peaks on the membrane surfaces created dynamic light and shadow on the façade and they also helped to prevent sagging in the fabric. Before the design of the Olympic Shooting Gallery, Magma Architecture experi­ mented with shaping PVC fabric for the Head In exhibit at the Berlinische Galerie. Tis

16

How Do We Stretch?

FIGURE 1.17 Roof assembly at the London Olympics Shooting Gallery. Photo: Lena Kleinheinz, Courtesy of MAGMA Architecture.

FIGURE 1.18 Structural support at the façade. Photo: Hufton & Crow. Courtesy of MAGMA Architecture.

strategy was then further developed into the larger architectural assemblies. In the Shooting Galleries, the circular frames are tensioning rings that stretch the fabric into a taut surface (see Figure 1.18). Te colored fabric circles not only animate an expressive façade but also take on functional purposes – they accommodate entryways or vents that draw in and exhaust air. With framed stretched assemblies, the membrane will conform to the shape established by the rigid structural framework. Membranes are tailored to ft the form of the frame. Infated cushions, stretched by air, are mainly centered on ETFE foils that we discussed earlier in this chapter. Multiple layers of ETFE foils are welded together at its edges. Like in the Allianz Arena and Media-TIC, the air-infated ETFE cushions at the Beijing National Aquatics Center, also known as the “Watercube,” are individual components so that

17

Why Stretch?

FIGURE 1.19 Mechanical connection at MediaTIC ETFE cushion. Photo: Lisa Huang.

they are easy to install and replace if the ETFE foil is punctured. Te infated cushions set into a metal frame are fastened in place onto the façade. Te infated cushions act as thermal barriers for the building. Since temperature and air pressure changes during a day, the cush­ ions typically require an integrated mechanical system to regulate air infation and to keep the ETFE foils taut. Tis mechanical system is integrated with the cushion framing system and regulates every cushion individually (Figure 1.19). In the Allianz Arena, the infated cells are connected together so fexible joints mediate between each panel to accommodate for movement in the façade assembly (Figure 1.20). In Media-TIC, the infated cushion and framing are held of an exoskeleton building structure. In the Watercube, the infated cush­ ions are fastened to the exterior and interior of the space-frame structure (Figure 1.21). With stretched assemblies, the entire building can also be infated. Tese pneu­ matic structures use air pressure within the building or within the assembly to infate sealed membrane constructions. Air pressure increases thermal insulation and the tension from infation supports the membrane assembly without a structural framework. Pneumatic struc­ tures require a mechanical system to maintain and regulate the air pressure, otherwise it has no form. In an infated assembly, the tailoring of the membrane construction embodies the structure, the building form, and the interior space. Te infated membrane needs to be anchored to the ground, but other components like a steel structure are not needed. In Kengo Kuma’s Tee Haus in Frankfurt, the pavilion is a double woven ePTFE fabric membrane that is infated to create the building form (Figure 1.22). Tis Tenara fabric

18

How Do We Stretch?

FIGURE 1.20 Joint between ETFE cushions at the Allianz Arena. Photo: Lisa Huang.

is a product that has a high resistance against extreme temperature and UV radiation and it does not lose its strength. Te white translucent fabric panels are welded into an interior membrane and an exterior membrane. Ten these two membranes are welded into one sealed membrane construction. Te welds connecting interior and exterior produce an array of pinch points on the fabric surface (Figure 1.23). When air is pumped into the layered assem­ bly, the welded connection points create an internal structure that supports the assembly form without a structural frame. Te interior and exterior membranes in combination with air infation create tension that self-supports the pavilion. Te Ark Nova designed by Anish Kapoor and Arato Isosaki for the Lucerne Festival used a single membrane infated and air-pressurized to form an occupiable con­ cert space (Figure 1.24). Te 500-seat performance space traveled through earthquake- and tsunami-hit Japanese towns. Te elastic plastic balloon is approximately 100 feet wide, 118 feet long, and 59 feet high. It is extremely light and can be easily transported and stored. Te translucent purple membrane is a PVC-coated polyester fabric that is UV-resistant and waterresistant. Te entire balloon has a metal tube sewn into its bottom edge. Tis metal tube is

19

Why Stretch?

FIGURE 1.21 Wall assembly detail at the Watercube. Photo: Fanghong [CC BY-SA 3.0 (https:// creativecommons. org/licenses/by -sa/3.0)].

FIGURE 1.22 Infating Kengo Kuma’s Tee Haus pavilion. Photo: courtesy of Kengo Kuma Associates.

20

How Do We Stretch?

FIGURE 1.23 Interior of infated Tee Haus pavilion. Photo: Courtesy of Kengo Kuma Associates.

FIGURE 1.24 Aerial view of the Ark Nova. Photo: courtesy of Lucerne Festival.

21

Why Stretch?

FIGURE 1.25 Ark Nova before infation. Photo: courtesy of Lucerne Festival.

FIGURE 1.26 Interior view of Ark Nova performance space. Photo: cour­ tesy of Lucerne Festival.

fastened to a frame structure that anchors to fat ground to create an air seal (Figure 1.25). At one end of the balloon, mechanical equipment blows in air to maintain air pressure to keep the balloon infated. Te steel cable ties down the infated structure. Te balloon’s toroidal shape relies entirely on the infation of the single membrane to stretch the membrane into a unique form and a usable space (Figure 1.26). Te tailoring of the membrane must be perfect to avoid any wrinkles in the structure. In working with stretched assemblies, the patternmaking, cutting, and seaming of membrane are critical for complex geometric forms and smooth unwrinkled surfaces. Not only do we have to design the connections between structure and membrane, but we have to

22

How Do We Stretch?

be aware of the points, edges, and corners in the assembly that take on the most stress. Te stretched assembly tends to be more vulnerable, so we are concerned with making the assem­ bly resistant to tearing and puncturing. Te potential problems do not have to deter us in attempting a stretched assembly. Instead, they can be qualities that help us defne assemblies in new and exciting ways.

Note 1

Frei Otto and Ludwig Glaeser, Te Work of Frei Otto, (New York: Museum of Modern Art, 1972), 8.

23

What Happens When Stretching?

What Are the Failures/Limitations/ Problems We May Encounter? Te stretched assembly relies on equilibrium between the membrane and a structural strategy to generate form and space. Any structural imbalance could cause wind-uplift, tearing, and sagging in the membrane. When we select the membrane material, we must consider the build­ ing application and the environmental conditions. If the cut and pattern of the membrane are not perfectly coordinated with the structure system, it could result in added stresses in the membrane. Overstretching of the membrane compromises the material; there is bound to be a breaking point. Te beneft of working with an elastic or fexible material is the potential for fuidity in form. Tis depends on how the membrane is shaped, how it is anchored, and how it is held in tension. Stretching in a building assembly is akin to tailoring clothes, not only in the use of fabric but in the methods of creating form – darts, hems, pins – and in the way it touches the body – drapes, tucks, and clings. Improper tailoring can lead to undesirable malfunctions. Te primary building typologies using stretching strategies are temporary pavil­ ions or stadium roof structures. With very few materials, we can enclose large spaces and achieve qualities of lightness, low cost, and easy installation. How else can we think about stretching assemblies? In this section, we will focus on the questions that emerge in the opera­ tion of stretching and examine approaches that explore stretching characteristics.

Composite Assemblies: How Do We Integrate Rigid and Stretched Materials? In the examples we discussed so far, stretched assemblies occur as translucent façade enclosures taking advantage of the thinness, lightness, and elasticity of membranes. What are the char­ acteristics and efects of weight and gravity on stretched assemblies that are layered with other dissimilar materials? We will look at two signifcant historical assemblies with elastic and rigid materials – Le Corbusier and Iannis Xenakis’s Phillips Pavilion at the 1958 Brussels Expo and Paul Rudolph and Ralph Twitchell’s Healy Guest House – to demonstrate the willingness to attempt something innovative and to test its viability. 24

1.3

What Happens When Stretching?

FIGURE 1.27 Exterior view of the completed Phillips Pavilion. Photo: Starink, Eindhoven © F.L.C. / Adagp, Paris, 2019 sauf pour l’église de Firminy:© F.L.C. / ADAGP, Paris [année/year] et José Oubrerie [Conception, Le Corbusier architecte, José Oubrerie assistant (1960–1965). Réalisation, José Oubrerie architecte (1970–2006)] et pour la Chapelle Notre Dame du Haut à Ronchamp: © ADAGP, Paris [année/year].

Both the Philips Pavilion and Healy Guest House stretched steel wire or straps to function as a primary framework to support another material. Both projects tested composite roof enclosure assembly that integrated elasticity and stifness difer­ ences in materials. Te Philips Pavilion integrated concrete panels, while the Healy House used fberboard. With the Phillips Pavilion, Le Corbusier and Xenakis experimented with steel cables forming a structural net to support concrete precast panels for the pavilion enclosure (Figure 1.27). Le Corbusier was involved in the preliminary pavilion concept, but at the same time, he was preoccupied with the design of Chandigarh. Le Corbusier mainly focused on the interior exhibit for the Philips Pavilion. He needed the enclosure of pavilion to be solid for acoustic purposes and concrete was ideal for the exhibit’s acoustic needs. It is interesting for us to note and later compare that during this time, Candela was experimenting with the construction of thin shell concrete structures in paraboloid forms. For the Phillips Pavilion, Xenakis designed a complex hyperbolic paraboloid; however, the entire form could not be made with cast-in-place concrete. As an alternative, Xenakis proposed steel wire cables stretched from cast-in-place concrete ribs. He directly translated the lines of structural forces into the lines of steel cables to achieve the paraboloid form. Precast concrete panels were then hung from the steel cables. Te construction of the Philips Pavilion was a complex series of steps. Te pre­ cast concrete panels were not uniform in shape, so they sculpted large sand piles to replicate each curved surface of the pavilion. Te sand was hand-packed into a form and then the concrete was hand-packed on top of the sand mold and around a layer of reinforcing steel. Tin wood frames were set into the concrete to subdivide the surface into panels. Once the concrete panels set, each panel was numbered and the sand was cleaned of the surface of the panels. In the construction of the Philips Pavilion, the precast concrete panels were set in place frst using wood scafolding (Figure 1.28). Ten, tension cables spanned between the cast-in-place concrete ribs and foundation. Te precast concrete panels were intermittently fastened to but not dependent on the steel cables. On the pavilion exterior, the weight of the curved concrete panels stretched the steel cables but followed the formal and structural geometry. Te exterior steel cable net grazed the surface of the precast panels and the net functioned as a tensioned structural system for the concrete ribs. A reinforcing steel wire mesh was applied to the interior face of precast panels. Gunite was then sprayed on the pre­ cast panels and wire mesh to create a uniform and continuous surface on the pavilion interior. Te Phillips Pavilion was demolished after the exposition, so the long-term lessons of the construction are unknown. In 1951, the Healy Guest House, also known as the Cocoon House, by Rudolph and Twitchell was an experiment with a composite stretched roof for a small permanent structure (Figure 1.29). Rudolph was interested in fnding an inexpensive construction sys­ tem and he was fascinated with the ‘Cocoon’ product used by the military to protect naval ships when not in use. Cocoon was a spray-on fexible vinyl plastic that was new technology for waterproofng. Rudolph and Twitchell wanted to test the potential of Cocoon as a roofng material for the house (Figure 1.30). 25

Why Stretch?

FIGURE 1.28 Cast-in-place concrete ribs and construction of Phillips Pavilion. Photo: Herbert Behrens / Anefo [CC0] © F.L.C. / Adagp, Paris, 2019 sauf pour l’église de Firminy:© F.L.C. / ADAGP, Paris [année/year] et José Oubrerie [Conception, Le Corbusier architecte, José Oubrerie assistant (1960–1965). Réalisation, José Oubrerie architecte (1970–2006)] et pour la Chapelle Notre Dame du Haut à Ronchamp: © ADAGP, Paris [année/year].

FIGURE 1.29 Construction of the Healy House Steinmetz, Joseph Janney, 1905–1985. View showing workers constructing architect Ralph Twitchell’s cantilever roof house on Siesta Key near Sarasota, Florida. 1951. Black and white photonega­ tive, 4 × 5 in. State Archives of Florida, Florida Memory. , accessed 18 June 2019.

26

What Happens When Stretching?

FIGURE 1.30 Workers spray­ ing on Cocoon plastic Steinmetz, Joseph Janney, 1905–1985. View of workers spraying Cocoon plastic roofng material on ceiling during construction of Twitchell’s cantilever roof house on Siesta Key near Sarasota, Florida. 1951. Black and white photonega­ tive, 5 × 4 in. State Archives of Florida, Florida Memory. , accessed 18 June 2019.

Te design concept of the Healy Guest House was to create a single room liv­ ing space that opens to the outdoors. To reinforce this idea, the roof drapes in the center to lift the roof up on its long edges. Rudolph and Twitchell proposed a steel tensioned roof structure. Steel straps were welded to edge beams on opposite walls and draped in a catenary curve. Te steel straps functioned as a reinforcing structure for the composite roof assembly. Te fat bars of cold-rolled steel were half an inch wide and one-eighth of an inch thick. Each bar was welded along a steel edge beam one foot on center (Figure 1.31). Each steel bar spanned 22 feet across. On top of the steel bars, they placed half-inch-thick fberboard. Ten 2 inches of fexible insulation mat were clipped to the steel slats. In the fnal step, Cocoon (vinyl plastic) was sprayed on the interior and exterior surface. Te sprayed vinyl plastic would produce a fexible roof that Rudolph and Twitchell hoped would be an innovative strategy to absorb hurricane winds instead of resisting those forces. Te Healy House roof was designed and constructed with a shallower curve in the center to allow rain to run of the ends of the house. Rudolph and Twitchell tried to minimize the roof assembly to maximize lightness and efciency. Unfortunately, the roof leaked almost immediately after construction.1 Te weight of the steel straps and the lightweight Cocoon assembly still pulled downward due to gravity. Also, in the heat of Florida sun, the roof materials expanded at diferent rates causing stress tears in the vinyl plastic surfaces. In the roof assembly, the steel bars stretched across the house as independent elements. Tere were no cross straps to fasten the steel bars into a net or mesh. Te structural forces only ran along

27

Why Stretch?

FIGURE 1.31 Welder installing steel straps for the Healy House roof, Steinmetz, Joseph Janney, 1905– 1985. Close-up view showing a welder at work during construction of Twitchell’s cantilever roof house on Siesta Key near Sarasota, Florida. 1951. Black and white photonega­ tive, 4 × 5 in. State Archives of Florida, Florida Memory. , accessed 18 June 2019.

each individual strap. Te fberboard in theory would provide lateral structure, but each steel bar expanded and contracted independently. Rudolph and Twitchell had frst tested this composite assembly of rigid and elastic materials. But once the assembly was built on site, the materials behaved diferently in the heat and humidity. In contrast, the rigid concrete panels in the Phillips Pavilion were not fastened directly to the fexible steel net therefore allowing the steel cables to expand and contract as needed. Most likely, the weight of precast concrete panels in the pavilion would overstretch the steel cables in the long run. Although the original Cocoon House experiment failed, the house is still in use to this day. In 1990, the roof was replaced with a conventional built-up roof to stop the leaking problem. In the China Academy of the Arts, Kengo Kuma stretched taut thin stainless-steel cables to hold reclaimed roof tiles as a façade screen. Te building is a series of shifted spaces embedded into the sloped landscape. (Figure 1.32). Kuma used the local clay roof tiles on the building roofs and continued the use of the roof tile on the vertical plane in the facades. Stainless-steel cables, crisscrossed in a diamond pattern anchor between vertical steel plates, the ground, and a steel angle along the roof edge. Te façade assembly has two sets of wires creating two identical layers spaced four inches apart. Te roof tiles fastened onto both lay­ ers of cables to unify the delicate screen assembly (Figure 1.33). In the façade, the roof tiles appear to foat in mid-air. Tension in the stainless-steel cables was essential to hold the roof tiles in place. Te China Academy of the Arts building has a double skin – a glass weather enclo­ sure approximately three feet behind the stretched cable screen. Te thinness of the cables cast a dynamic play of light and shadows into the building that further emphasize the foating roof tiles (Figure 1.34). Zooming out to the scale of the building, there is also an interplay

28

What Happens When Stretching?

FIGURE 1.32 China Academy of the Arts, tiled roofs and roof tile façade screen. Photo: Eiichi Kano, courtesy of Kengo Kuma Associates.

FIGURE 1.33 Façade screen detail at the China Academy of the Arts. Photo: Eiichi Kano, courtesy of Kengo Kuma Associates.

between the tiles on the building roof and in the façade. Te screen façade is fush with the edges of the roofs and the façade roof tiles are oriented in the same direction as the building roof tiles. At the detail scale, the roof tiles foat with the stretched stainless-steel cables. At the building scale, the roofs are stretched vertically apart consequently producing facades that appear as expansions of the roof.

29

Why Stretch?

FIGURE 1.34 Natural light trans­ mitted through the façade. Photo: Eiichi Kano, courtesy of Kengo Kuma Associates.

STUDENT EXPERIMENT How Do We Negotiate Between Flexible and Stif Materials Systems? Zachary Wignall | University of Florida Using stretchy fabric, Zach experimented with creating three-dimensional surfaces and making apertures. He started with a simple wood frame and tested various ways of creat­ ing peaks and valleys on the surface of the fabric. Creating three-dimensionality in a fat surface: Zach point-loaded the fabric to create peaks on the exterior surface. His earlier tests used components that put too much stress on singular points of the fabric resulting in ripped fabric (Figure 1.35). Te point of contact between the fabric and structure needed to be more gradual to reduce ten­ sion in the fabric. A fabric stretched in three-dimension has to absorb added stresses. Te act of stretching also varies translucency, the visibility through the fabric, and the appearance of three-dimensionality in the fabric. Te opacity and translucency of the stressed fabric depend on the fabric’s weave and the viewing angle. Creating apertures: Zach frst tried to make apertures in rectangular shapes, but the fabric did not work with the orthogonal geometry. Te fabric bunched and tore at corners when it could not produce smooth transitions (Figure 1.36). Tere was not an equal distribution of tension at rectangular corners, so it stressed the fabric and created unde­ sirable ripples in the fabric. In stretching fabric, Zach had to negotiate between a rigid orthogonal frame and a fexible material. Te fabric worked best with rounder forms. Keeping the fabric in tension: Zach used a wood frame which needed to be rigid enough to withstand the tension that accompanies a stretched membrane. Under

30

What Happens When Stretching?

FIGURE 1.35 Wignall.

Preliminary material tests in framing and stretching fabric. Photo: Zachary

FIGURE 1.36

Detail of the fabric at a rectangular aperture. Photo: Lisa Huang.

31

Why Stretch?

stretched forces, the wood frame naturally wanted to collapse inward, so the frame’s components were thickened and struts were added to add support to the frame. Allowing light to pass through the assembly was important, so Zach had to fnd the right combination of fexibility and translucency for the fabric. On the assembly’s exterior side, the frame’s overlapping shadows and membrane were visible through the fabric. On the interior side, the frame dominated the fabric (Figure 1.37). As we saw in the Olympics Shooting Gallery, an interior membrane helps obscure the structure. Keeping the fabric consistently taut in the frame: Zach reinforced the edges of the fabric to prevent ripping at the points of tension. A metal rod was sewn into the hem to provide equilibrium in stretching the material on all sides. Te fabric needed to be made of a material that doesn’t expand and contract. Over time, the fabric’s stretchi­ ness would likely succumb to the efects of gravity and environmental conditions such as the sun’s heat or wind forces.

FIGURE 1.37

32

Final assembly and original conceptual drawing. Photo: Zachary Wignall.

What Happens When Stretching?

Pliability and Sagging: How Do We Overcome the Effects of Gravity and Give Dimension to Flatness and Floppiness? Te beneft of using fexible membranes is the possibility of creating shadows and depth in the membrane. But a fexible membrane has the risk of sagging surfaces and weaknesses in the material. Otto emphasized pure tension and structural equilibrium in the membrane. However, contemporary projects have tested other strategies of negotiating tension within pliable membranes. At the 2014 Venice Biennale Architettura, Barkow Leibinger experimented with a kinetic fabric wall where the surface of a stretchy transparent screen membrane mechani­ cally changed its surface geometry. A wood framework supported a mechanical system with cantilevered metal posts that pushed and pulled the vertically oriented fabric (Figure 1.38). Te cantilevered metal posts pierced through and fastened to the fabric. Te fasteners were approximately 2 inches wide to help distribute the stresses in the fabric when the posts pushed in and out. Te mechanical system was programmed to create diferent patterns of peaks and valleys creating a continuously changing vertical topography. When the fabric is fat, the wall appears opaque from oblique viewpoints. When the fabric stretches out, the fabric’s weave stretches and becomes more transparent producing dynamic patterns of shadows and depth. Te fabric was constantly in motion which alleviated tension in the stretched fabric. Te choice of fabric becomes important to make sure that the stretching and releasing of the fabric resists sagging and maintains its pliability. Te 2015 Serpentine Pavilion by SelgasCano experimented with ETFE foil, a less pliable material, to test its ability to mediate between diferent geometries and its shadow and light efects. In most ETFE applications, the foil is held in a frame and infation helps to smooth out the foil surface. In their installation, SelgasCano used mirrored, translucent, and 19 color variations of ETFE foil (Figure 1.39). Large sheets of ETFE wrapped around the white steel structural frame. In other sections of the pavilion, the ETFE sheets are held by

FIGURE 1.38 2014 Venice Biennale Kinetic Wall by Barkow Leibinger. Photo: Lisa Huang.

33

Why Stretch?

FIGURE 1.39 2015 Serpentine Pavilion by SelgasCano. Photo: Andrew Davidson at English Wikipedia [CC BY-SA 3.0 (https:// creativecommons. org/licenses/by -sa/3.0)].

metal edge bars connected to the steel frame and fastened at intervals to hold down the foil. SelgasCano used a series of round tubular framed arches, varying from angular to rounded shapes, that radiate of a central space. No arch shape repeats in the pavilion. Te ETFE foil had to negotiate between diferent geometries which challenged its ability to be taut. However, the shape of the pavilion and arch structures emerged through stretching the ETFE as much as possible. As a result, the frames distorted tension and produced wrinkles in the foil. Stretching a material between irregularly shaped frames will inevitably produce inconsistencies in the membrane. Te pavilion intentionally examines the behavior of ETFE foils when it is used without air infation and when it has to negotiate asymmetry. SelgasCano used large-scale sheets of the ETFE foil to test the efects of non-uniform geometry. All the crinkles and wrinkles in the pavilion surface are a study of the light, shadows, and refections that emerge and move along the surface. Te pavilion occupied the realm of experimentation that has infuenced consequent SelgasCano building projects. In permanent structures using ETFE such as Behnisch Architekten’s Unilever Haus located in Hamburg, the ETFE foils act as a double skin in the exterior assembly. Te façade of Unilever Haus has taut pleated panels of transparent ETFE foil that mitigate energy efciency and resistance of high winds along the Elbe River (Figure 1.40) Te single layer of ETFE is stretched over rigid steel frames. Glass would have been too rigid, while ETFE has the pliability to absorb wind forces. Within each large vertical frame, a smaller metal frame stretches the ETFE foil taut. An additional cable structure supports the ETFE and stretches the membrane into a stronger three-dimensional form. Te cable structure fastens across the width of the rigid frame. Ten paired cables are stretched apart by an adjustable steel stan­ chion that generates a peak in the pleats. Te form of the ETFE surface is dependent on the geometry created by the cables attached to the rigid frame. A steel cable sits on the inside and outside of ETFE intermittently between each stanchion. Tis holds the foil down and subdi­ vides it into smaller sections. Te ETFE foil stretching system is standardized even though each rigid panel has varied dimensions and geometry. Te slanted form of each ETFE panel refects the dynamic wind efects that surround the building (Figure 1.41). Te thin and delicate structural cable system disappears in the overall appearance of the façade. At the peak of the cable structure, the ETFE foil is not attached to the steel stanchion connection. Te gap between the connection and the foil reduces the possibility of

34

What Happens When Stretching?

FIGURE 1.40 Unilever Haus with outer façade layer of ETFE. Photo: Lisa Huang.

FIGURE 1.41 Partial façade and a close up of the frame. Photo: Lisa Huang.

35

Why Stretch?

FIGURE 1.42 Detail of the cable and ETFE assem­ bly. Photo: Zachary Wignall.

ripping foils against the wind stresses (Figure 1.42). Te ETFE foil is reinforced at its edges and at any contact between foil and cable to reduce stresses between the two components. Te detailed structural connections are designed to prevent wear of the durable but also delicate membrane. Te subdivisions within each steel frame make it easy to replace and maintain the ETFE foils. Te taut form of the ETFE façade transmits and catches light that produces an ephemeral enclosure around the building. Te fabric cocoon in Peter Zumthor’s Steilneset Memorial, on the other hand, plays up the efects of gravity on the fabric in its form and material use. Te 410-feet long cocoon is a Tefon-coated fberglass woven sailcloth that was hand-sewn into 17 tunnelshaped segments (Figure 1.43). Tese segments were prefabricated using sail production and fastening techniques and then these segments were sewn together on site. Te steel cables, stretched within a wood framework, pull the fabric cocoon at each seam of the fabric con­ struction. Te fberglass sailcloth is tailored to exaggerate fabric being pulled taut. At the cable connections, the fabric is reinforced and reaches toward the steel cables. Between the cable connections, the fabric concaves inward on all sides which challenges the illusion of slack in the fabric (Figure 1.44). Te steel cables pierce through the cocoon but the cables do not impact the interior space. Te fabric segments are intentionally cut and patterned to appear as if the fabric is stretching.

Alternative Strategies: How Else Can We Take Advantage of a Membrane’s Natural Inclination to Cling and Drape? Earlier in this chapter, we discussed how structural systems of hanging, framing, and infat­ ing hold membranes at its edges or at points to stretch the membrane. Tese structural forces shape the membrane’s form and impose a stable but activated state of tension on the stretched material. Like the clothes we wear, fabric naturally clings and drapes over the body. What if the structural frame plays a neutral role and allows the membrane to submit to gravity?

36

What Happens When Stretching?

FIGURE 1.43 Partial elevation of the Steilneset Memorial. Photo: Zachary Wignall.

In the Hinman Building at Georgia Tech University, Ofce dA encases a spiral stair using a stainless-steel net in place of typical guardrails. Te stainless-steel net enclosure connects around the top and the bottom of a central steel post that stretches from the ground to the roof. Te net spans between foor and ceiling and pulls apart to accommodate passage and also address code compliance for the stair (Figure 1.45). A tension ring at the top helps to spread the net apart. Pushing outwards from the center takes advantage of the net’s stretchi­ ness and creates space for the spiral stair. Te stair is a folded steel plate welded to a structural central post and the net is knitted into a tube form. It is essentially a stocking that is stretched around the stair structure. Te substructure for the handrail and guardrail consists of three metal tubes spi­ raling along the stairs (Figure 1.46). One tube runs parallel to the steps and a metal wire binds the tube and mesh to keep it in place. Tere is also an efciency of materials in the assembly – no mechanical fasteners are needed between the net and the stair construction.

37

Why Stretch?

FIGURE 1.44 Exterior and interior detail at the connection between fabric and steel cables. Photo: Zachary Wignall.

FIGURE 1.45 Spiral stair in the Hinman Building. Photo: Lisa Huang.

38

What Happens When Stretching?

FIGURE 1.46 Detail between stainless-steel net and structure. Photo: Lisa Huang.

Te second tube ofsets from the steps and helps to pull the stainless-steel net away from the third tube that is the handrail. Tis tube does not touch the net in order to accommodate building code requirements of clear dimensions from handrail to other surfaces. Te hand­ rail is supported by intermittent vertical posts that are welded to the top edge of the folded plate steps. Te net is connected to an edge cable that gives rigidity to its edges. Te tension generated in pushing the net outward creates clear space and the enclosure. Te net is not completely taut as it clings to the edges of the stair or the rails. It still has some give and it stretches just far enough to comply with building codes. Two projects from SO-IL – the Blueprint installation and the Kukje Gallery – explore the concept of clinging and draping using an exterior membrane. Te Blueprint instal­ lation at the Storefront in NYC (2015) hung a plastic membrane outside of the Storefront façade originally designed by Steven Holl and Vito Acconci. Te plastic flm is fastened at the top and bottom with a wood frame. Te Storefront’s exterior wall panels are rotated open and heat applied to the plastic tightened the membrane to the façade (Figure 1.47).

FIGURE 1.47 Blueprint installa­ tion illuminated at night. Photo: Iwan Baan.

39

Why Stretch?

Te installation heated plastic, using a shrink-wrapping storage technique called ‘mothballing.’ Tis technique is related to the Cocoon application at the Healy House. Shrink-wrapping clings to projecting surfaces and heating creates tension that holds the plas­ tic in place. No additional fasteners were needed in the installation. It is semi-transparent membrane so light inside the Storefront projected through the plastic flm giving depth to the façade surface. Hints of the rotated door panels protruded giving the plastic membrane texture and shadow (Figure 1.48). When light projected on and through the membrane, it revealed the three-dimensional forms and space hidden behind the plastic membrane. Façade edges parallel to the taut plastic surface were crisp lines in the installation. Ten, in negotiat­ ing diferent geometries, the crisp lines faded into the natural drape of the plastic membrane. At the Kukje Gallery in Seoul, SO-IL drapes a veil of chainmail over solid build­ ing volumes to create a uniform and ephemeral building form (Figure 1.49). Te gallery occupies the central space while program elements such as the egress stairs, elevator shaft, and entrances are volumes that abut the gallery space. Te shape and dimension of these volumes refect the functional spaces. To unify these building components, SO-IL encloses the build­ ing’s geometric forms using a custom chainmail fabric. Chainmail is made up of a series of metal rings linked together to form a textile that has the ability to stretch and cling. For the Kukje Gallery, the chainmail veil is com­ posed of 510,000 handcrafted stainless-steel rings engineered by the exterior wall fabricator. To avoid bulges, wrinkles, and bunching of the chainmail, the size, pattern, and distribution of chainmail links was rigorously tested. Te chainmail is fastened at the top of the gallery building and anchored to the ground (Figure 1.50). It expands over the building forms and corners of the building forms catch onto the chainmail without the need for additional fas­ teners. Te veil negotiates between orthogonal corners to rounded forms easily and elegantly produces a blurred enclosure for the gallery (Figure 1.51). Te changes in geometry efect the visibility through the chainmail veil. From oblique angles, the veil becomes opaque. Te over­ lapping of the chainmail fabric and the shadow cast onto the building forms adds dynamic

FIGURE 1.48 Three-dimensional surface of the Blueprint installa­ tion. Photo: Iwan Baan.

40

What Happens When Stretching?

FIGURE 1.49 Chainmail draped over Kukje Gallery building volumes. Photo: Mani Karami.

FIGURE 1.50 Detail of connec­ tion at top of the chainmail screen. Photo: Mani Karami.

41

Why Stretch?

FIGURE 1.51 Detail of the chainmail draped at the entry. Photo: Mani Karami.

spatial depth to the overall building appearance. Te weight of the chainmail submits to grav­ ity and takes on form-fnding responsibilities. Te Kukje Gallery’s unique attachment system allows the chainmail to hang in tension and cling to building corners and edges.

Lightness and Weight: How Do We Make a Typically Temporary Assembly Look More Permanent? Te typical stretched membrane is most often used for installations and pavilions for its light­ weight and economical characteristics. Tin membranes and fabrics have ephemeral qualities that also make them vulnerable. We are accustomed to seeing stretched assemblies as temporary lightweight building components such as awnings, canopies, and tents. How do you elevate a material strategy that is associated with temporary constructions? How can the stretched mem­ brane assembly overcome its impermanent and vulnerable appearance? How can we capitalize on a stretched assembly’s lightness while also conveying an impression of permanence? We will frst look at a temporary installation that is assembled and dissembled annually. Tubaloon by Snøhetta defnes an overhead condition for an outdoor stage and amphitheater during the annual jazz festival in Kongsberg, Norway. Te installation’s form is essentially a hybridized version of Otto’s saddle tent. Tubaloon has a single membrane of coated PVC fabric, so the lightweight and thin membrane allows the entire installation to be easily stored in a minimal amount of space. Tere are steel tube frames that defne the edges of the tent structure. Two points of the steel structure anchor to a foundation while four steel cables pull outward to stabilize the form (Figure 1.52). One end of the structure is a horizontal canopy for the stage and the other end swoops up to form a horn that projects music from the stage. Te tubular steel structure is hidden, encased in the membrane’s hemmed edges. Te Tubaloon installation integrates a mechanical system within the steel structure, so the steel tube frame is also an air duct. Tis outer seam of the membrane construction is an infated air tube acting as a pneumatic edge beam that pulls the entire membrane taut (Figure 1.53).

42

What Happens When Stretching?

FIGURE 1.52 Tubaloon infated and anchored. Photo: Mahlum [Public domain].

FIGURE 1.53 Tubaloon during installation. Photo: Thomas.bjorn­ dahl [CC BY-SA 3.0 (https://c reativecommons. org/licenses/by -sa/3.0)].

43

Why Stretch?

Te installation is balloon-like in appearance, but the form is a geometrically complex tent. It integrates a framed stretched assembly with an infated edge beam construction that elimi­ nates wrinkles and appears more solid. However, the stretched assembly still looks temporary due to the steel cables holding the installation in place. At the Serpentine Sackler Gallery in London, the edge beam for a fabric roof uses a stif surface material. Te building’s composite roof construction is a play between soft and hard – a fabric membrane and plastic panels defne the roof. For this addition to the Sackler Gallery, Zaha Hadid Architects juxtapose a delicate stretched material structure against the existing brick building. Te roof of this nontraditional addition hovers above the existing Sackler Gallery roof and lightly touches the existing building. A clerestory window mediates between addition and existing building, so the new construction respects the old while also expressing its own individuality (Figure 1.54). Te Serpentine Sackler Gallery addition is a big roof structure with glass walls completing the enclosure. Te membrane roof is two layers of glass-fber woven cloth. Te exterior membrane uses a PTFE coating for UV protection and the interior membrane is coated with silicone. Te fabric membranes pull taut creating undulating landscapes in white for both the interior ceiling and exterior roof. Te Serpentine Sackler Gallery addition has a series of internal columns that pierce the roof structure forming skylights. Tese steel col­ umns push the interior membrane upward like tent posts. As a result, the ceiling surface has a billowy appearance. Te columns are further detached from the roof structure through a gap of light between the two membranes and each column. Te interior membrane has a pattern of visible welded seams within the continu­ ous fabric surface. Tis pattern refects an underlying structural assembly within the fabric membrane itself. Along the edge of the roof, fber-reinforced plastic panels cap the interior and exterior membrane edges (Figure 1.55). A concealed roof gutter occupies the joint between the membrane and the plastic panel. On the underside of the roof, the glass wall is positioned at the joint between the fabric membrane and exterior plastic cladding (Figure 1.56).

FIGURE 1.54 Serpentine Sackler Gallery, Zaha Hadid Architects. Photo: Luke Hayes, courtesy of Zaha Hadid Architects.

44

What Happens When Stretching?

FIGURE 1.55 Roof edge detail at Serpentine Sackler Gallery. Photo: Ardfern [CC BY-SA 3.0 (https:// creativecommons. org/licenses/by -sa/3.0)].

FIGURE 1.56 Section drawing of the roof edge. Photo: courtesy of Zaha Hadid Architects.

45

Why Stretch?

FIGURE 1.57 The Serpentine Sackler Gallery roof under con­ struction. Photo: Lisa Huang.

Like the Tubaloon installation, the Serpentine Sackler Gallery roof is supported by a steel tube structure that defnes the edge of the roof and holds the membrane taut (Figure 1.57). Te structural frame is composed of two steel tubes that are held together with intermittent steel I-beams. Te outer steel tube is smaller in diameter than the inner steel tube and the spacing between the two tubes varies in distance. Te outer tube helps to sup­ port the fber-reinforced plastic edge cladding. Te steel structure dips downward and grazes the ground at points, so the roof’s steel frame can anchor to the ground. Te fber-reinforced panels are key in protecting the membranes and in establishing a hard edge for the roof. Tese panels are molded to conform to the membrane’s geometry and they allow the fabric the free­ dom to stretch, drape, and foat of its structural supports (Figure 1.58).

FIGURE 1.58 The Serpentine Sackler Gallery illu­ minated at night. Photo: Luke Hayes, Courtesy of Zaha Hadid Architects.

46

What Happens When Stretching?

In contrast, Shigeru Ban’s Centre Pompidou-Metz layers an undulating struc­ ture beneath the roof membrane to defne the roof’s form and appearance. Six layers of glue-laminated wood are woven together like a large-scale fabric mesh that drapes into a contiguous column and roof structure. Tis wood roof shell has a hexagonal pattern and through precisely engineered CNC-milling, it is a complex geometry of curves. In the Centre Pompidou-Metz, there are two scales of fabric used for the roof assembly – the woven wood and the fabric membrane (Figure 1.59). An internal concrete structure intersects and interacts with the fabric and wood roof assembly. Like the Serpentine Sackler Gallery, a glass assembly mediates between the ground and the roof assembly. Ban emphasizes the fuidity of textiles through the wood structure. Te woven wood seamlessly drapes down, lightly touching the ground to form column structures supporting the roof. Te light and thin fabric fastens to the underlying woven wood assembly (Figure 1.60). Only a single membrane of translucent fberglass and PTFE membrane stretches over the woven wood structure. Te fabric is installed in long strips ranging in widths between 20 to 30 feet and the seams are highly visible within the white membrane. Te fabric fastens to brackets along all the wood beams. Te membrane covers the entire build­ ing to protect the space from rain, sun, and wind. In the daylight, the roofscape geometry is emphasized by the parallel seams of the fabric. Te membrane has a 15% translucency so that the interior light illuminates at night and highlights the woven wood roof structure (Figure 1.61). Te metal frame tower at the highpoint of the undulating roof is reminiscent of Otto’s tent structures. But in this building, Ban further investigates the potential of stretched

FIGURE 1.59 The roof assem­ bly of the Center Pompidou-Metz interlocking with the concrete build­ ing core. Photo: Didier Boy de la Tour, courtesy of Shigeru Ban Architects.

47

Why Stretch?

FIGURE 1.60 Layering of the woven wood structure with the PTFE membrane. Photo: Didier Boy de la Tour, courtesy of Shigeru Ban Architects.

FIGURE 1.61 The roof illumi­ nated at night. Photo: Didier Boy de la Tour, courtesy of Shigeru Ban Architects.

materials as light and ephemeral components in creating enclosed and permanent weath­ ertight constructions. Since stretched membranes need some sort of structural framework in order to hold the membrane in tension, Ban develops a unique woven and layered wood structure in lieu of standard structural components. Tis wood structure is also delicate in appearance to work in harmony with the membrane. Te integration of additional materials in the stretched assembly either as an edge condition or a supportive layer, like Ban’s woven wood structure, allows the membrane to be both delicate while also permanent.

48

What Happens When Stretching?

STUDENT EXPERIMENT How Do We Take Advantage of a Material’s Stretching Potential? Alexander Tomas and Evan Vander Ploeg | University of Florida Silicone rubber is typically used for mold-making, sealants, and fabric coatings. Te material is elastic, durable, and available in a range of translucencies. Silicone rubber starts out as a liquid that hardens into a fexible solid, so it can cast into any shape. Alex and Evan wanted to explore the architectural potential of silicone rubber. Tey infated panels of silicone to test the silicone’s behavior and its breaking point when it was stretched. Manipulating the material: Alex and Evan were interested in kinetic movement in building components and silicone rubber is material that accommodates fuctuating movement. Tey studied movement in these panels at two scales – the geometry and form of the infated air chamber and the ability of an assembly of panels to expand and contract. Tey were also curious about whether an infated silicone rubber panel could provide thermal insulation like infated ETFE cushions. Tey found that the design and dimensions of the air chambers would not only stretch the silicone but in the act of stretching and infating, the silicon could be controlled to move in certain directions (Figure 1.62). Establishing the breaking point: Troughout the process of making the panels, Alex and Evan confronted numerous issues and challenges that would help them under­ stand how to control the silicone rubber. In casting panels with an air chamber, they needed to maintain a consistent dimensional thickness of silicone rubber or otherwise it would distort the infation. Te thickness of the webbing determined the resist­ ance in the material and the amount of stretching that could occur (Figure 1.63).

FIGURE 1.62

Test panel infated to the point of breaking. Photo: Lisa Huang.

49

Why Stretch?

FIGURE 1.63 Composite images of the infated silicone panel prototypes. Photo: Alex Thomas and Evan Vander Ploeg.

Te points of least resistance, where the silicone is thin in the panels, created weak­ nesses in the material. At that breaking point, the silicone does not return to its origi­ nal shape. Te silicone elasticity worked for the frst few infations, then the material gets overstretched. Understanding the point of failure let them know how to better control the material. Controlling those limitations: Tese were handcrafted silicone panels, so Alex and Evan did not have the beneft of more precise technology or equipment to control dimensional consistency in the material. However, they looked at the limitations within their control and then they tried to see what they could do with larger panels. Tey rigorously and iteratively explored numerous panel designs correcting incon­ sistencies and perfecting their technique. Tey tested variations in the air chamber webbing to control movement of the silicone panel itself. Infating the panel natu­ rally contorted the silicone rubber material. Alex and Evan created an assembly of panels that could open and close with air infation. If they intentionally thickened and thinned the silicone rubber, then they could determine the direction the material would stretch (Figure 1.64).

50

What Happens When Stretching?

FIGURE 1.64 Final assembly of silicone panels opened and closed. Photo: Alex Thomas and Evan Vander Ploeg.

Stretching the Material Itself: How Can We Make a Rigid Material Look Soft and Fluid? In this chapter, we have mostly examined stretching at the scale of the building assembly. But we can also investigate ‘stretching’ in terms of fexible limits within the material compo­ nent itself. Many materials that are rigid and stif can be manipulated to look soft and fuid. Some materials distort through processes that expand the material properties. Metals, glass, and certain types of plastics can be slumped and stretched using heat. Metal panels can be embossed using a mechanical press. Wood can be steamed to stretch the grain’s elasticity. Stretching these materials requires knowing the limits to which the material becomes fragile. Tey have breaking points, but there are strategies to manipulate material compositions and appearances to create surface textures, shadows, and three-dimensional forms. Metal components are altered through heating or compressing the material’s mol­ ecules. Te surface geometry of thin metal panels of aluminum, copper, stainless steel, and other metals can be deformed. Adding three-dimensional form to fat metal panels also pro­ vides more rigidity and strength to the panel. In the New Museum of Contemporary Art, SANAA uses anodized aluminum pan­ els that have a pattern of slits cut into them and then the panel is stretched. Tese expanded metal panels start as a fat metal sheet that pulls into a three-dimensional screen. Typically, expanded metal panels have an industrial or supporting role in construction assemblies func­ tioning as grates, fencing, and metal lathe supporting stucco. Te New Museum uses a largescale version of expanded metal and capitalizes on its ability to flter light as an exterior cladding

51

Why Stretch?

FIGURE 1.65 New Museum by SANAA. Photo: Xuancheng Zhu.

material (Figure 1.65). Te metal mesh is installed as large façade panels that are fastened with a minimal number of clips of the back-up wall assembly. Te slits cut into the metal panel are proportional to the building scale. When the panel stretches apart, the metal distorts into curved surfaces that interact with natural light at diferent points of the day (Figure 1.66). A big challenge we must address in detailing assemblies is how materials turn a corner. In the New Museum, the panels overlap on the façade creating a seamless appear­ ance. Te expanded metal panels do not overlap when turning the corner because the mesh itself stretches into a three-dimensional component. Te gap between the metal panels at the building’s corners reinforce the foating surface efect of the expanded metal (Figure 1.67). Te metal screen is held of the surface of the aluminum façade panels, casting a shadow and giving the building an ephemeral appearance. Tis shadow shifts throughout the day keep­ ing the façade dynamic and making it difcult to determine the precise edge of the building. Te expanded metal screen in combination with brushed aluminum back-up panels create a ghostly shroud encasing the building.

52

What Happens When Stretching?

FIGURE 1.66 Detail of the expanded metal panel façade at New Museum. Photo: Xuancheng Zhu.

FIGURE 1.67 Corner condition at the New Museum metal panels. Photo: Xuancheng Zhu.

53

Why Stretch?

Herzog & de Meuron have numerous projects that have used stretched metal components. Te Signal Box uses horizontal bands of copper pulled up to create openings between the bands. In the de Young Museum, the copper panels are treated with overlaid patterns of perforations and embossed dimples creating a façade texture and fltering natural light into the building (Figure 1.68). Te Messe Basel’s approach to metal façade panels is an interesting project for us to examine and compare to SANAA’s New Museum building. In Messe Basel, the building is a large exhibition center complex where the seams in the façade skin open to create apertures. Te bands of metal façade panels stretch to create these openings. Tese metal horizontal bands stagger and push back and forth to create a bas­ ket weave pattern like the New Museum façade (Figure 1.69). Te Messe Basel façade looks like expanded metal panels at a large scale, however, the construction of the metal façade is actually a series of small metal panels assembled to appear like an expanded metal screen. In the New Museum, the façade slits are cut out of large metal sheets. In the Messe Basel, the slits are the resulting gap between small metal panels fastened to a framework creating the illusion of fuctuation in the façade. Te small metal panels are oriented horizontally and attached one-by-one to cre­ ate the staggered pattern and texture of an expanded metal screen. Tis assembly strategy provides better control of the surface’s geometry (Figure 1.70). Te panels stretch upward to permit light and view into the building. Te thin sheets of metal bend easily without special equipment to produce a smooth surface. Te framework and brackets supporting the metal panels establish the form of the surface geometry. Te framework becomes a small edge beam providing structural support to every row of thin metal panels. Te framework is also set back from the bottom edge of the metal panel so that it is hidden by shadows. In the New Museum, the stretching of the metal panel is uniform so the geometry of the openings in the screen is also uniform. In the Messe Basel, using large expanded metal

FIGURE 1.68 Embossed copper façade panels at the de Young Museum. Photo: Lisa Huang.

54

What Happens When Stretching?

FIGURE 1.69 Metal façade at Messe Basel. Photo: Lisa Huang.

FIGURE 1.70 Detail of façade with visible seams between each metal panel. Photo: Lisa Huang.

sheets would be problematic in the assembly because of variations in aperture sizes. Te parts of the façade that stretch open would create deformations in both vertical and horizontal directions that would be more difcult to achieve using a single metal sheet in the construc­ tion assembly. Constructing the façade with smaller panels allows more control and precision in the surface geometry. Te scale and consistency of stretching in a metal component have to be considered because the distortions may afect the larger assembly.

55

Why Stretch?

FIGURE 1.71 Glass panels at Prada Aoyama by Herzog & de Meuron. Photo: Lisa Huang.

Glass appears to be a rigid building material, but it is technically a very slow-mov­ ing viscous material. When glass is heated, it becomes more pliable and it can be manipulated. If heat is strategically applied, glass panels slump to a form. Herzog & de Meuron have not only experimented with stretching metal but also glass panels in several projects. For Prada Aoyama, each glass panel is slumped to create a curved surface. Te diamond-shaped glass panels are concave or convex surfaces in the façade (Figure 1.71). In the Elbphilharmonie façade, window edges curve in and out to create deformations in the surface. Glass panels with round openings and curved edges are used for balconies (Figure 1.72). Natural light interacts with the glass deformations in the façade. Te glass panels undulate thus creating fuid surfaces with a rigid material (Figure 1.73). In REX’s Vakko Fashion Center, each glass panel in the façade is patterned with a large ‘X’ across the surface of the glass (Figure 1.74). REX wanted the exterior skin to be as minimal, light, and transparent as possible so that the building’s interior activity could be seen in the exterior. In order for the glass curtain wall to be as minimal and as open as pos­ sible, REX challenges the conventional glass curtain wall assembly. Instead of relying on mul­ lions, the clear Low-E glass panels take on structural responsibilities. Manipulating fat glass panes into a three-dimensional surface increases the rigidity and strength of the glass panel.

56

What Happens When Stretching?

FIGURE 1.72 Convex and con­ cave glass in the Elbphilharmonie façade. Photo: Zachary Wignall.

FIGURE 1.73 Undulating windows at the Elbphilharmonie. Photo: Lisa Huang.

57

Why Stretch?

FIGURE 1.74 Glass surface at the Vakko Fashion Center. Photo: Courtesy of REX.

FIGURE 1.75 Overall view of glass texture at the Vakko Fashion Center. Photo: Iwan Baan.

Te outer glass pane of the insulated glass unit is slumped with the ‘X’ shape. Te glass is essentially stretched when it slumps. In manipulating the material, the ‘X’ pattern distorts the glass and provides dynamic light and shadows cast onto and into the building. Te stretching process in combination with the molded form structurally strengthens the glass and eliminates the need for perimeter mullions. Tis simplifes the interior surface of the glass, reduces the bulk and shadows cast by mullions, and creates an uninterrupted glass surface that wraps around the building (Figure 1.75).

Note 1

58

Christopher Domin and Joseph King, Paul Rudolph: Te Florida Houses, (New York: Princeton Architectural Press, 2002), 38.

Chapter 2

Why Cast?

2.1

What Can We Cast?

Material Considerations A cast assembly involves a building material set into a removable mold or formwork, trans­ forming from a liquid to a solid. Te fabrication process generally requires constructing a formwork that is the negative of the desired cast, pouring in the liquid material, and then removing the formwork once the material cures or sets. Te beneft of casting is the material’s ability to take on any shape both at the large scale of the building and at the small scale of the detail. Te casting material is, at frst, viscous unlike typical sheet building materials, so its initial plasticity allows the possibility of expressive free forms and continuous surfaces. Cast materials can take on any complex geometry and three-dimensional shape as long as there is a workable mold or formwork. Te size of the fnal cast is determined by the design and dimen­ sions of the formwork. In the construction process, the quality and craft of the formwork is just as important as the cast it produces. Te oldest known and largest unreinforced cast concrete building structure is the Pantheon in Rome which has a masonry base and a concrete dome that spans an incredible distance of approximately 142 feet. On top of a heavy masonry wall, the dome is a singular roof structure with cofers shaped by a wood formwork. Te ancient Romans discovered that water mixed with lime turns the material stone-like and consequently they produced the earliest recordings of casting as a building assembly operation. Tey used slaked lime with volcanic ash to make a concrete-like material called pozzolana. Recent scientifc research on concrete has encouraged a return to the use of the Roman concrete composition because of its ability to resist cracking and deterioration from salt and moisture. In the Pantheon’s building section, the base of the dome is thicker to carry the dome’s structural load down to the foundation (Figure 2.1). Te concrete at the oculus thick­ ens around the aperture to act as an edge beam. At its base, the concrete is approximately 21 feet thick and at the oculus, it is 3.9 feet thick. Te aggregate is heavy at the base of the dome and lightens toward the top of the dome. Cofers were incorporated to also lighten the dome structure (Figure 2.2). Te cofers not only reduce the amount of material used, but its imprint on the concrete dome provides a relative scale within a massive and monolithic construction.

61

Why Cast?

FIGURE 2.1 Section drawing of the Pantheon.

Without cofers, a uniform smooth curved surface of concrete makes it more difcult to com­ prehend the height and incredible scale of the space. To this day, the Pantheon exists as a testament to the strength of a cast concrete construction. Te concrete casting technique was lost after the fall of the Roman Empire in the 5th century. In its reemergence during the second half of the 19th century, concrete was considered an inexpensive material. Frank Lloyd Wright was an early experimenter with con­ crete construction. In 1909, he frst used concrete in the Unity Temple to take advantage of the economical material. Wright also wanted the building to appear heavy and massive and he recognized concrete’s potential for fexibility of form and establishing a lasting presence (Figure 2.3). Te wood formwork was designed so that it could be reused, however, ultimately the cost of the project was twice the original budget because of complications during con­ struction. Te fnished concrete surface shows that the wood formwork warped during the casting process. As a ‘new’ building method, the construction industry was still learning how to produce quality and efcient concrete assemblies. Wright had reservations about casting concrete after the Unity Temple because of visible form marks left behind on the concrete.1 However, later in the Solomon Guggenheim Museum, he continued working with cast concrete and tried a more adventurous and com­ plex cast form. Te construction of the entire museum structure was cast-in-place reinforced concrete. To achieve his iconic design for the museum, one-of plywood formwork was built to achieve the complex geometry (Figure 2.4). Instead of pouring concrete into the form, the concrete is sprayed into the formwork. A process referred to as ‘gun-placed concrete’ or gunite. Around the same time as the Guggenheim construction, Berthold Lubetkin tested a pure expression of casting building material in the Penguin Pool London Zoo. In this pro­ ject, Lubetkin created a simple but elegant design of two intertwining ramps cantilevered over an elliptical pool. Te ramps were cast on-site using reinforced concrete and wood formwork. Te ramps are uniform concrete planes with consistent thickness and without addi­ tional structural forms or building components. His playful ramp showcased the penguin

62

What Can We Cast?

FIGURE 2.2 Coffered cast con­ crete dome at the Pantheon. Photo: Lisa Huang.

exhibit and emphasized the potential thinness and geometric clarity achievable in casting a building material (Figure 2.5). Te advantage of casting at the building or component scale is a resulting largescale uniform material and a fnal product that reduces all the parts and pieces usually needed in a constructed assembly. Casting as an assembly strategy does not necessarily require addi­ tional materials and fasteners. Te fnal product can appear as a singular building form. Casting at a building scale is predominantly achieved using concrete; it is a material that is monolithic, continuous, and versatile. However, a large-scale concrete cast is not scale-less because casting usually reveals traces of the formwork and the construction process. Using a single material like concrete in construction can be economical, but cast­ ing requires more thought and efort in planning ahead for the fnal product. Tere is unpre­ dictability during the construction process that can afect refnement in the fnished product. A building cast entirely in concrete appears to be a simple material assembly, but the con­ struction process of casting can be complicated. Tere are numerous factors and sequential steps in the process that create opportunities for error.

63

Why Cast?

FIGURE 2.3 Unity Temple concrete exterior. Photo: Teemu008 from Palatine, Illinois [CC BY-SA 2.0 (https://c reativecommons. org/licenses/by -sa/2.0)].

FIGURE 2.4 Guggenheim Museum under construction. Photo: GottschoSchleisner, Inc., photographer [Public domain].

Typical Casting Materials and Components Forming and shaping in the casting process requires the construction of a mold – an inverse or negative of the fnal form. Casting uses a viscous material that hardens to assume the shape of a given mold. Tere are multiple building materials that have this transformative charac­ teristic of converting from liquid to solid form. Te basic composition of concrete consists of cement, water, and an aggregate. When mixed together, a chemical reaction occurs between water and cement that perma­ nently hardens the liquid mixture into a stone-like material. Aggregates are necessary to

64

What Can We Cast?

FIGURE 2.5 Penguin pool at the London Zoo. Photo: gillfoto [CC BY-SA 4.0 (https:// creativecommons. org/licenses/ by-sa/4.0)].

provide additional surface area for binding within the mixture. Te ratio of ingredients varies depending on the concrete specifcations and other additives can enhance characteristics of concrete. As we know, concrete is naturally strong in compression but weak in tension. For concrete to be most useful as a structural material, steel reinforcement is embedded in the cast to increase its tensile strength and structural integrity. Concrete is the most common construction material used in contemporary architecture. Because it is durable, strong, and monolithic, it is the primary material used for large-scale building components that require structural strength. Concrete is an entirely opaque material that is genuine and honest in character; concrete is what it is and it reveals all kinds of inconsistencies in its surface. Because of this, concrete is often considered a rough and unapologetically utilitarian material. It is typically the structural back-up wall that supports a more refned cladding material. Concrete is a material that provides signifcant mass and thickness. If it is cast too thin, it becomes fragile. If thermal insulation and moisture protection is not a concern, then an enclosure of cast concrete is very capable of standing on its own. Peter Markli’s La Congiunta is a three-room gallery that uses cast concrete as a continuous vertical enclosure housing the artwork of Hans Josephsohn (Figure 2.6). Te design and construction of the gallery needed to be economical and low maintenance. Te building did not need to be insu­ lated, so additional components were unnecessary for the building enclosure. Te glazed roof is supported by steel trusses set into the concrete walls, further emphasizing the simplicity of the cast enclosure. Te exterior surface of La Congiunta eschews cladding and instead, the cast concrete reveals horizontal striations of wood formwork and points of connection for the form ties (Figure 2.7). Our perception of cast concrete’s monolithic and rough character often portrays the material as cold, industrial, economical, and brutal. Te surface fnish of a concrete cast imprints the casting process and formwork or after the casting process, a surface fnish is applied to the concrete through sandblasting, bush hammering, or polishing. Te quality

65

Why Cast?

FIGURE 2.6 La Congiunta concrete volumes. Photo: Lisa Huang.

and fneness of concrete is dependent on its material composition and the casting process. Typically, the more refned the fnish of concrete, the more expensive the construction process. Cast stone is a variation of concrete using a white or gray cement and a manufac­ tured aggregate to achieve a lustrous surface appearance that replicates natural stone. Cast stone is commonly used to produce masonry modules. It is a more cost-efective construction strategy than using stone blocks and the modules can be customized. In the Louisiana State Museum and Sports Hall of Fame by Trahan Architects, cast stone is used as large cladding components that produce a complex curvature on the exte­ rior and interior spaces (Figure 2.8). At the scale of the material, the cast stone is luminous and catches natural light. Te curved geometry also emphasizes the light and shadows that engages the building. Te sinuous surfaces in the museum interior are composed of 1,250 cast stone panels designed and fabricated with a very tight one-eighth of an inch construc­ tion tolerance. So, the fnished construction appears as a uniform and continuous surface. Te largest cast stone panel is 18 feet by 12 feet weighing 9,600 pounds. Because of space limitations in the project, the cast stone follows tightly to the steel structure (Figure 2.9). Te molds for the cast stone panels were milled from high-density foam and the fabricators used a proprietary dry-cast method instead of standard wet casting. Te panels were precast to control precision during the production. Plaster is made of a very fne powder of gypsum, lime, or cement that solidifes when mixed with water. Plaster is most commonly applied as a protective layer over walls and ceilings. It is a smooth white material that also casts very fne and elaborate detail, but it works best as an architectural fnish material because it is very brittle and fragile. Since it is a delicate material, plaster does not have any load-bearing capabilities and is typically used for interior installations. It is cast as detail components such as decorative trims and architectural molding. Although it does not have the same properties or behaviors as concrete, plaster is often used for casting scaled models because it is an easy material to manage.

66

What Can We Cast?

FIGURE 2.7 Concrete detail at La Congiunta. Photo: Lisa Huang.

FIGURE 2.8 Louisiana State Museum and Sports Hall of Fame exterior and interior. Photo: courtesy of Trahan Architects.

67

Why Cast?

FIGURE 2.9 Louisiana State Museum and Sports Hall of Fame cast stone panel installation. Photo: courtesy of Trahan Architects.

FIGURE 2.10 Plaster cast at Ini Ani. Photo: Kazuyo Oda.

For the Ini Ani cofee shop, Lewis Tsuramaki Lewis created a feature wall using plaster that refected the function of the space. Tey cast diferent types of plastic cofee cups lids into a long horizontal plaster panel that spanned the length of the café. Te fneness of plaster picked up all the small details in the plastic lids. Te surface texture and the bright white color of the plaster refected light through the glass entry door into the small cafe (Figure 2.10).

68

What Can We Cast?

MATSYS’s P-Wall installation uses spandex and wood dowels as a formwork for plaster wall panels. Te fabric is stretched over the dowels and the weight of the poured plas­ ter further stretches the spandex. It produces a varied three-dimensional surface depending on how the plaster settled in the stretchy fabric form. Plaster has a fne consistency, so it is able to pick up details like the tight woven texture of the spandex fabric. Cast iron and metal alloys such as aluminum and bronze are typically cast at the component scale. Concrete and cast iron emerged during the Industrial Revolution as a ‘new’ building material used for structural components in industrial buildings or infrastruc­ tural structures. Before the emergence of steel as a structural material, there was a period when cast iron was considered a primary structural material. Cast iron is a metal alloy that is smelted and then poured into a mold. Te casting of iron construction elements established preliminary experiments with prefabrication in building construction. Cast iron components could be extremely slender, especially in comparison to masonry construction. Cast iron, later overshadowed by steel, has strength in compression but it does not handle tension well. Steel is less brittle and more economical and its manufacturing process is more efcient than cast iron. Te Crystal Palace was a large-scale enclosed cast iron structure erected for public occupation at the Great Exhibition of 1851. Te building is known for its transparency from the use of the largest glass panes at that time. Te extent of transparency would not be pos­ sible without the help of a thinner structure system (Figure 2.11). Casting iron allowed for intricate shapes and ornamentation for the structural elements. Tese cast iron structures were thin and elegant in form. Te embodied lightness in construction resulted in fooding the space with natural light. To cast other alloys, metal billets are heated to revert to a molten state, and then the molten metal is poured into a mold. Once the metal cools, it solidifes and it can be removed from the mold. Tere is a range of common methods for casting metal – lost wax, plaster mold, sand casting. Once the metal cools, the surface can then be polished if so desired.

FIGURE 2.11 Crystal Palace cast iron structure. Photo: Albert and Victoria Museum.

69

Why Cast?

At the Paul Smith Abermarle Street storefront in London, 6a Architects clad the façade with custom cast iron panels. Tese panels are cast with a digitally modeled pat­ tern that protrudes or recesses on the metal surface. Blocks of high-density polyurethane foam were CNC milled to produce a replica of each metal panel. Te foam panels were then imprinted into traditional sand-casting beds. Instead of using a traditional cast iron alloy, fabricators used a spheroidal graphite iron. Te fabrication process also included an uncon­ ventional fnishing step where the iron metal panels are intentionally rusted. To protect the oxidized surface, a special coating called Hammerite’s Kurust is applied to produce a black patina (iron tannate) and to protect the panel’s surface from deterioration. During the cast­ ing process, fasteners were embedded into the back of each panel to hide the attachments. Between abutting panels, there is a lap joint concealing the supporting steel substructure while also permitting thermal expansion in the cast iron. In contemporary architecture, cast metals are mostly ornamental components in buildings. Herzog & de Meuron’s 40 Bond Street is located in a New York City neighbor­ hood near elegant cast iron buildings from the mid-19th century. At 40 Bond Street, curved green glass cladding is molded into forms that resonate with the proportions of neighbor­ ing historic cast iron structures (Figure  2.12). At the base of 40 Bond Street, a 140-foot long cast aluminum sculptural gate provides the building residents with privacy screening along the public sidewalk. Te pattern of the gate is a digitally generated design translating grafti into a three-dimensional form (Figure 2.13). Te gate design was milled into 4-inch thick dense foam and molten aluminum was cast into the prepared mold. Te casting of aluminum instead of milling aluminum results in large panels with complex geometries and it minimizes material waste. In general, the waste in the casting construction process lies in the discarded formwork. Glass is another material that can be cast into components. Cast glass is a process rooted in ancient Roman and Egyptian history. Glass is heated to its molten state and then poured into a mold made of sand, lost wax, metal, or graphite and then the glass hardens as

FIGURE 2.12 Bond Street façade with glass cladding and cast aluminum fence. Photo: Xuancheng Zhu.

70

What Can We Cast?

FIGURE 2.13 Detail of cast glass and the cast aluminum. Photo: Xuancheng Zhu.

FIGURE 2.14 Hearst Ice Falls installation in the lobby of the Hearst Building. Photo: Xuancheng Zhu.

it cools. Hearst Ice Falls is a cast glass water feature in the lobby of the Hearst Corporation Building in New York City (Figure 2.14). James Carpenter Associates designed faceted cast glass blocks that would refect natural light and water fowing over the glass surface. Each glass block is fastened at an angle on a steel substructure. Usually, cast glass blocks are not perfectly smooth surfaces, so the irregularity in the material further captures and distributes light (Figure 2.15). Te oratory entry door in the Holy Rosary Chapel by Trahan Architects is also made of cast glass. Instead of constructing a mold that would give texture to the cast glass,

71

Why Cast?

FIGURE 2.15 Cast glass block detail. Photo: Xuancheng Zhu.

the texture of ripples in the glass door comes from the process of molten glass poured into cooling layers. Te rippled layers of glass enhance the refection and refraction of light. Te door pivots on stainless steel rails at top and bottom that support the glass. Te cast glass is thin along the vertical edges, approximately 1/2 inch, and thickens in the center to three inches. Te variation in shape helps to increase the cast glass door’s strength. Another common cast glass component is channel glass, which is a panel that is held at the top and bottom by metal rails. Te result is a translucent surface that transmits light like in Steven Holl’s Nelson Atkins Museum (Figure  2.16). Channel glass is molten

FIGURE 2.16 Channel glass façade at the Nelson-Atkins Museum. Photo: Carol M. Highsmith [Public domain].

72

What Can We Cast?

glass that is cast into ribbons and then before the glass cools, it is run through steel rollers to form a U-shape giving each panel structural rigidity. Channel glass is typically oriented vertically to maximize the panel’s inherent structural strength. If the channel glass assembly requires thermal resistance, insulation is placed within the channels. In casting plastics, two components – a catalyst and a binder – mix together caus­ ing a chemical reaction that then hardens the mixture. Te most common of these synthetic polymers is cast acrylic resin. Te acrylic mixture is placed into a mold made of a material that is unafected by the acrylic curing process. Casting acrylic requires a controlled environ­ ment because the casting process generates toxic fumes. Cast acrylic is a durable, fexible, and transparent material. It is lighter in weight and less expensive than glass, but its surface scratches easier. Te transparent rods used in the Heatherwick Studio’s Seed Cathedral, the UK Pavilion at the 2010 Shanghai Expo, used two ways of molding acrylic. Te pavilion was a cube building volume that has 60,000 clear extruded acrylic rods extending from the build­ ing envelope. Te efect results in an ethereal form that captured light and swayed in the wind (Figure 2.17). Each exterior fber optic was 24.5 feet long and 3/4-inch in diameter. Te fber optics seemingly pierced through the pavilion and obscured the physical boundary separat­ ing inside from outside. Te exterior acrylic components attached to aluminum sleeves that physically pierced the pavilion’s weather enclosure. On the interior of the pavilion, seeds were cast into acrylic at the widened end of a custom mold. Te length of the interior acrylic rods varied in length to form the interior space while also presenting an extensive seed collection (Figure 2.18). Light trans­ mitted through the acrylic components in both directions. During day, the interior was illuminated by natural light following the sun’s movement. While at night, all the acrylic rods were illuminated with an LED light source embedded in each aluminum sleeve. Te LED light both extended inward and projected outward to illuminate the whole pavilion at night.

FIGURE 2.17 Exterior view of the Seed Cathedral. Photo: Xuancheng Zhu.

73

Why Cast?

FIGURE 2.18 Detail of the seeds cast into the acrylic rods. Photo: Xuancheng Zhu.

STUDENT EXPERIMENT

How Do We Cast a Light-Transmitting Concrete

Panel and What Else Can We Do with It?

Tim Beecken | University of Florida Tim was interested in additional efects fber optics could contribute to translucent con­ crete. He experimented with diferent strategies to set plastic fber optics within a con­ crete cast and he found the most efective way to incorporate fbers optics was to insert each fber individually in a time-consuming and tedious process. Keeping fber optics in place: Te design of the formwork was critical to Figure out a method to hold each fber optic in place. Te process of pouring concrete into the mold could easily shift fber optics around. Tim created a formwork using laser cut acrylic sheets with diferent patterns of holes. Each fber optic was threaded through the holes in the formwork. It was difcult to cut fber optics to match the exact thick­ ness of the concrete panel. So, Tim had to use longer fbers that were trimmed once the concrete cast was removed (Figure 2.19). Determining proper spacing between fber optics: Tim had to balance between the spacing of the fber optics and the consistency of the concrete mix. Air bub­ bles trapped within the fber optic mesh would further weaken the concrete. Fiber optics that were too close together crumbled when he removed the mold. Tim had to experiment with the consistencies of the concrete mix to fnd the right viscosity. He used a very fne aggregate that would easily fow around and between the fbers. Manipulating the fber optics: Most light-transmitting concrete products transmit light directly through the concrete panel. Tim was also curious about whether the fber optics could also distort the light. Using small concrete panels, Tim experimented

74

What Can We Cast?

FIGURE 2.19

Studies of rotating fber optics in a concrete panel. Photo: Timothy Beecken.

FIGURE 2.20 Beecken.

Rotated image through the light-transmitting concrete panel. Photo: Timothy

with twisting and bending the fber optics. In one experiment, he achieved a rotated shadow from one side of concrete to the other (Figure 2.20). He twisted the fbers to produce a new visual efect but introduced new complications to the casting process. Rotating the fber optics limited the dimensions of each panel and the twisted fber optics produced more areas for air bubbles to gather.

75

Why Cast?

Atypical Casting Materials and Components Concrete is the most common building material in casting. Tere is a wide range of concrete qualities since it is easy to incorporate additives in the material composition. New advances in concrete technology have generated breakthroughs that have altered concrete’s standard characteristics and performance.

Light-Transmitting Concrete: How Do We Make an Inherently Opaque Material Transmit Light? Felix Candela is known for experimenting with structural concrete shells and umbrellas, so we will discuss Candela’s work at length later in this chapter. In 1954, at the High Life Textile Factory located in the Coyoacan neighborhood of Mexico City, Candela used his umbrella structures but challenged the opacity of the concrete. He tested the potential for concrete to transmit light into a space by casting glass blocks into the concrete roof. However, the experi­ ment failed because the glass blocks generated too much solar heat gain within the building. Te interior space overheated making it extremely uncomfortable for the factory workers. To resolve this issue, the glass blocks were completely covered with asphalt paper and tar to prevent heat gain.2 Te glass blocks were small relative to the entire concrete structure but the assembly was inappropriate for an environment with strong sun exposure. Candela’s experiment questioned whether concrete needed to always be an opaque material but also demonstrated that in casting, the concrete can be manipulated unlike other building materials and assemblies. Casting allows the addition of other materials into the building assembly that can generate new aesthetic, functional, and structural characteristics. Since 2001, companies such as LiTraCon and Lucem have contributed advance­ ments in light-transmitting concrete as a building material. Tey have experimented with various smaller scale transparent materials as additives in the concrete or with transparent resins as a binding material. Tere has been success in creating translucent concrete by adding glass or plastic optical fbers as an ‘aggregate’ that spans between the concrete faces. At this point, translucent concrete is predominantly a manufactured precast panel with proprietary technology. Panels are typically produced with alternating layers of concrete mix and fber optics. Transparent fbers can be placed individually but this makes the produc­ tion process too expensive and time-consuming. Semi-automatic processes increase efciency by producing optical fber meshes or bundles that also provide reinforcement in a concrete mix consisting of fne materials. Since the panels are supposed to transmit light, both sides of the concrete panel need to be clear of obstructions. It becomes difcult to incorporate the typical steel rebars used in reinforced concrete. In 2013, Gianni Botsford Architects and Litracon constructed the Garden Smoking Pavilion, the frst self-supporting translucent concrete building. Te translucent panels are approximately 3.15 inches thick and each panel has a dimension of 141.7 inches × 90.5 inches (360 × 230 cm). Five of these panels are used for the foor, walls, and roof of this outdoor pavilion. Acrylic fber optics are embedded in a grid pattern into the concrete panels. Although this is a small structure, it relies on highly advanced engineering because the concrete does not have the typical steel reinforcement. Te structure for the pavilion is

76

What Can We Cast?

FIGURE 2.21 Translucent con­ crete panels at the Garden Smoking Pavilion. Photo: James Morris.

internalized in the panels. Dowel connections and stainless-steel reinforcement is strategi­ cally positioned within a pattern of translucent elements (Figure 2.21).

Ultra-High-Performance Concrete: How Do We Compensate for Weaknesses in Concrete? In 2013, Rudy Riccioti’s Museum of the Civilizations of Europe and the Mediterranean (MuCEM) in Marseille was the frst building constructed with pre-stressed structural ele­ ments using Ductal Ò, an engineered fber reinforced with ultra-high-performance concrete (UHPC) (Figure 2.22). Te French company, Lafarge, addressed concrete’s inherent tensile weakness and developed a concrete mix that is signifcantly higher in strength than con­ ventional concrete. Strong reinforcement fbers are added to concrete, so conventional steel reinforcement is not necessary in the concrete. Tere is also no shrinkage or creep in the UHPC. Te material is very suitable for pre-stressed applications. Ductal has a fner grained composition so it works well with complex geometries and more precise molds. MuCEM uses Ductal for its pedestrian footbridge, branching structural columns, and lacy façade screens. Te pedestrian footbridge connecting between MuCEM and Fort St Jean is composed of 20 precast concrete segments spanning a total distance of 377 feet (see Figure 2.23). Te six-foot-tall pre-stressed UHPC segments gracefully extend over water without any intermediate structural supports. Te footbridge lands at the top of the museum creating a unique entry condition where the roof establishes a new ground that frames the ocean and the edge of the city marked by Cathedrale La Major.

77

Why Cast?

FIGURE 2.22 Ductal panels at MuCEM façade and roof. Photo: Lisa Huang.

Te museum’s structural system is a series of pre-stressed concrete columns encir­ cling the conditioned space of the museum and consequently providing column-free interior spaces. Te columns are rounded like tree trunks and branch upward outside of the glass façade. Conventional concrete tends to have inconsistencies in the surface from air bubbles and color deviations. Ductal has a fne-grained composition, so the surface of MuCEM’s concrete columns are smooth, tight-pored, and consistent in color. Te outer edge of the building is an open-air occupiable space between the glass weather enclosure and the concrete façade screen. Like the columns’ surfaces, the concrete façade panels are incredibly smooth. Te screen façade consists of approximately 400 Ductal panels wrapping the building and folding onto the roof. Ductal does not shrink during the curing process and the fabrication process is extremely precise. As a result, the precast panels had a tolerance of less than a millimeter. Te screen panels, held by cantilevered struts, extend

78

What Can We Cast?

FIGURE 2.23 Pre-stressed foot­ bridge at MuCEM. Photo: Lisa Huang.

FIGURE 2.24 Pedestrian walkway between ductal panels and structural columns. Photo: Lisa Huang.

approximately 20 feet away from the glass façade. Te walkway is suspended from the roof structure, so it foats freely between the glass wall and the Ductal screen (Figure 2.24). Each cantilevered strut fastens to four panels, further emphasizing the lightness of the UHPC panels. Because of the fneness of Ductal, the panel’s intricate geometric pat­ tern looks light despite its inherent heaviness. Te façade screen conveys lightness not only in weight, but also in how the screen flters natural light into the building. All the concrete

79

Why Cast?

components in the building are tinted a charcoal gray color. Te dark color of the Ductal screen absorbs natural light and reduces the amount of refected light entering into the museum.

Air-Purifying Concrete: How Can a Building Material Contribute to its Surrounding Environment? As mentioned, it is standard practice to incorporate additives in concrete to increase con­ crete’s performance in terms of strength, durability, and aesthetics. Te next generation of concrete technology addresses issues of sustainability, health, and welfare. At the 2015 Milan Expo, Nemesi Architects’ Palazzo Italia introduced new developments in concrete composi­ tion and characteristics. Te architects worked with Italcementi’s i.active BIODYNAMIC cement that has the ability to clean and flter the air. Italcementi’s product contains additives in the cement mix that converts pol­ lutants in the air into inert salts. Tis cement was used in the Palazzo Italia’s 700 precast cladding panels that created the pavilion’s screened façade (Figure 2.25). Te design of the concrete panels is a dense matrix of layered branches. Te panels at the base of the building are solid and then the percentage of opening in the panels increases as the pavilion rises in height. Each panel is unique with varying degrees of porosity and surface depth. Te panels were precast and the i.active BIODYNAMIC cement was injected into steel forms and synthetic resin molds. Te tightly managed production of the panels pro­ duced a refned appearance of three-dimensional layers of concrete. Concrete panels in the Palazzo Italia were a bright white color. Carrera marble aggregate and white cement were

FIGURE 2.25 Palazzo Italia with its air fltering concrete panels. Photo: David Oliva.

80

What Can We Cast?

added to the concrete to increase the luster. Technological advancements in the properties of building materials will inevitably establish a new norm for concrete casting. Te ability of cement to actively purify the air opens up new potentials in the environmental impact of building materials.

Key Issues to Consider in Material Selection As is the case in most building constructions, cost is the biggest determining factor. In the operation of casting, the selection of material is driven by the scale of the assembly. Are we casting the entire wall or components? What is our desired fnish for the casting? Casting insitu, also known as site cast or cast-in-place, is where the formwork is built on site and in place so that the cast material is in its position. Precasting is where dimensional panels are cast in a controlled fabrication facility and then transported to the site. With insitu casting, there is more potential for unpredictability and inconsistencies in the process which may compromise concrete quality. Precasting ensures precision in the fabrication process, fner detail, and higher quality fnish. Precast panels are fastened to structural wall, while insitu casting produces a continuous cast without additional components. Te process of casting occurs in almost every building project. Building founda­ tions are typically concrete cast insitu. With qualities of durability, rigidity, and strength, concrete is the most common material for casting at the large-scale of the building and the structure. If the concrete does not require a refned surface appearance, then it can be cast efciently and economically. To get precision and perfection in casting concrete, we would need to invest more care and efort in the quality of formwork, concrete mix, and construc­ tion. Metal, plaster, and glass are always precast since they are used as building components and require precision. For any cast material, diferent levels of refnement can be achieved if we give proper attention to the material’s needs and the factors that afect the casting process.

Notes 1 2

Terry L. Patterson, Frank Lloyd Wright and the Meaning of Materials, (New York: Van Nostrand Reinhold, 1994), 196. Maria E. Moreyra Garlock and David P. Billington, Felix Candela: Engineer, Builder, Structural Artist, (New Haven: Princeton University Art Museum, Yale University Press, 2008), 102–106.

81

How Do We Cast?

Typical Assembly Requirements Key Steps in the Casting Process Te key components and steps in the casting process consist of the following: mixing ingredi­ ents, assembling the formwork and the supporting structure, applying releasing agents, incor­ porating a reinforcing structure, vibrating the mix, cleaning exposed surfaces, curing and setting, removing the formwork, and treating surfaces once they are exposed. Te quality of a cast is not revealed until the mold or formwork is removed. Te number of steps in the cast­ ing process produces more opportunity for unpredictability in the fnal results (Figure 2.26). Ultimately, the details in casting, the articulation of surfaces and edges, and the structural integrity rely on the quality of construction in each of these steps.

Mixing Casting Ingredients Materials like metal and glass start as billets that are heated to their respective melting points and then poured into a formwork to set. Acrylics, like resin, start as a liquid form. Once it is mixed with a catalyst, it produces a chemical reaction that hardens the resin. Concrete is a mix of ingredients that produces a slurry. Te proportions of ingredients need to be precise to specifcations because other­ wise it can produce inconsistencies in the casting process. If the amount of catalyst is not in proportion to the binder, then an acrylic resin may not harden. Additives incorporated into casting materials can change the material’s behavior and characteristics. Typical admixtures for concrete can strengthen, change its color, or lighten its weight. Since the aggregate in con­ crete mixes vary in weight and particle size, the consistency of the mixture afects plasticity, the setting or curing time, and the strength of the material. Te complications that can occur with concrete during this step may result in 1. cement does not bind with the aggregate, 2. ingredients become stratifed because the consist­ ency of mix is unbalanced, 3. color diference, 4. slow curing time because there is too much water or crumbly concrete because there was not enough water in the mix. 82

2.2

How Do We Cast?

FIGURE 2.26 Student mishaps in casting con­ crete. Photo: Lisa Huang.

Assembling Formwork and Its Structural Support Te mold or formwork, also referred to as shuttering, is a necessity in casting. It is the struc­ ture that shapes the desired cast form. Depending on the complexity of the form, the materi­ als and labor costs for constructing formwork is often more expensive than the cost of the casting material itself. Concrete is a relatively economic building material but the construc­ tion cost of formwork typically has a bigger impact. Te formwork shapes the cast form, but the interface between formwork and con­ crete also afects the surface appearance of the fnal product. Various materials can be used for formwork depending on the casting material. For metals and glass, the formwork material must be able to withstand high temperatures required of the cast material. Typical formwork materials include sand, wax, plaster, metal, and graphite. Casting formworks for plastics requires materials that won’t bind to the plastic while it cures. Te formwork material has to be strong enough to contain the liquid and to withstand pressure from the liquid material to maintain its form. 83

Why Cast?

For concrete and plaster, the formwork material has to withstand contact with water present in the material mixture. Typical formwork surfaces for concrete are made with wood, steel, and plastics. Te formwork for concrete also has to address the weight of the concrete slurry and the downward force of the slurry, so additional structural bracing is often needed to support formwork and resist lateral forces. Te complications that can occur during this step can result in 1. warped or bulg­ ing casts if the formwork material and structure cannot withstand the forces of the casting material, 2. casting material seeping through gaps in the formwork if construction of formwork is vulnerable.

Assembling an Internal Reinforcing Structure Internal reinforcement is particularly important for cast materials like concrete that function as structural components. A reinforcing structure is not typically cast into metals, plastics, and glass because these materials do not have structural responsibility at the building scale. If a reinforcing material is placed within a cast, the two materials need to be compatible with each other. Since concrete is weak in tension, it is integrated with steel to make up for struc­ tural defciencies. Steel reinforcing bars are embedded and hidden within the concrete cast­ ing. Steel reinforcing should not be exposed on the surface because any water infltration will cause the steel to rust and consequently that deterioration weakens the concrete. It can later cause concrete to crack, spall, and jeopardize its compressive strength. Te reinforcing bars are tied together into a matrix and concrete is poured around it creating a composite assem­ bly. When a concrete cast changes in thickness, it is more likely to crack and break of at its weak points; thus, the added need for expansion joints and control joints. Te steel reinforce­ ment helps to negotiate any changes of form or dimension. Te complications that can occur during this step can result in (1) concrete crack­ ing. Tere is always some degree of cracking in concrete casts but improper placement of reinforcing may crack and produce opportunities for water infltration which consequently compromises the strength of the steel. (2) spalling and faking. Te steel reinforcement needs sufcient concrete coverage. (3) rusting at the surface of concrete. Te steel reinforcement must be held away from the surface of the casting.

Applying Releasing Agent Te formwork is removed once the cast materials have solidifed. Tere is direct contact between the cast material and the formwork, so there is the risk of the two materials binding together. If given the opportunity, concrete will easily attach and bite onto surfaces that have a degree of roughness. Some materials will naturally separate from one another, but typi­ cally releasing agents, such as sealants, oils, or silicone, are applied or sprayed onto formwork before casting to prevent binding. Te selection of releasing agent materials is based on what works best with the formwork material. Te choice of releasing agent can also afect the surface texture of the cast mate­ rial. Oils can absorb into the concrete and cause discoloration. Tick releasing agents can leave

84

How Do We Cast?

imprints of surface texture inconsistencies. Tere are some releasing agents that prevent the surface of the concrete from curing. Many cast concrete buildings have experimented with retardant releasing agents to get more complex surface textures. Te complications that can occur during this step can result in (1) formwork and casting sticking together, and (2) inconsistency in the cast material’s surface texture and color.

Vibrating the Mix When pouring a material, air bubbles are easily trapped in the casting. Depending on the size of the bubbles, it can compromise structural integrity and make it difcult to produce tight corners or consistent smooth surfaces. When concrete is poured, the mixture is vibrated to make sure the concrete properly encases the steel reinforcement. Air bubbles on the surface of a concrete cast may expose aggregate or steel reinforcement and reduce the required coverage to protect the steel. Tere is a delicate balance in how much and how vigorously to agitate a concrete mix in the casting process. Too much agitation can cause the ingredients in the concrete to segregate thus jeopardizing structural integrity. Te complications that can occur during this step can result in (1) honeycombing from air pockets disrupting smooth surfaces, (2) weakening structural integrity, (3) irregularity at corners and edges that are most vulnerable to bubbles gathering. Materials like concrete and resin will shrink when they set, so the exposed surfaces of material in the formwork need extra attention. Depending on its viscosity, the casting material may or may not self-level. Particularly in casting concrete foor slabs or other large surface areas, it helps to smooth or trowel the exposed surface. Te complications that can occur during this step can result in (1) inconsistent surfaces that would need to be sanded down afterward, (2) inconsistent thickness in the cast material.

Removing Formwork and Treating Surfaces Once a material cast sets, it is often difcult to alter its form. Metal and glass can be melted down again but concrete essentially turns into stone. Concrete is an unforgiving material; it picks up everything and it is tricky to fx afterward. Te concrete surface can be polished, sand blasted, or bush hammered to unify the surface. Otherwise, a layer of fnish concrete or stucco can be applied to the surface or the concrete is clad with another fnish material. Tere are a series of steps required in casting and many factors in the process that can afect the quality of the fnal product. Te work of Tadao Ando has consistently invested in the process of casting concrete. If we look at each of Ando’s projects there is clearly a con­ stant testing and refning of concrete in all steps of the casting process, particularly in the material mix and the formwork. Ando’s Koshino House was an early work with concrete where the formwork infuenced the concrete’s surface. Te plywood formwork bulged and warped slightly in the casting resulting in a textured surface and subtle shadow variations as natural light grazes across the concrete surface. Te concrete casting reveals that the formwork was horizontally oriented wood panels arranged in a grid. Six form ties held each formwork panel in place. Te

85

Why Cast?

formwork material was clearly wood because the shadows reveal that the wood reacted and warped from the moisture in the concrete mixture. Bulges at the seam between wood panels and at the form ties are visible across the concrete surface. As a result, the concrete surface is not completely fat – it has subtle waves and undulations throughout the surface. At the corners of each wood panel, we can see dimen­ sional variations in the surface of the concrete. What we think is beautiful about the concrete is that it reveals the unique characteristics and reactions of concrete in the casting process. Wood formwork must be sealed as otherwise the wood will absorb water in the concrete mix. Te water content soaks into wood and then the cement against the formwork surface is not able to chemically react and cure. If a releasing agent is not used or if wood formwork is not pre-soaked or sealed, then the surface of the concrete cast can be sandy. Te concrete in the Koshino House has a smooth surface, but the plywood panels in the formwork were warped in the casting. Te non-uniform texture reveals not only the formwork’s reaction in the process, but also demonstrates the craft required in casting the concrete wall. Te concrete’s texture captures the character of wood surfaces in contrast to the rough and industrial texture of concrete. Te wood formwork helps to relate the monolithic quality of concrete into the intimate scale of the house. Ando has spent his entire career working with cast concrete and his recent work demonstrates his expertise in casting. Ando’s Punta della Dogana museum achieves a high level of precision and refnement in site-cast concrete. His design is a surgical renovation of an existing brick building that was the former Customs House of Venice. Ando inserts a 23-foot high concrete room that acts as a central atrium in the middle of the museum. Two large skylights illuminate the double height space and cast light on the 11.8-inch thick polished cement walls (Figure 2.27). Te concrete surface is completely fush with no hint of irregularities in the sur­ face. In the Punta della Dogana, the concrete cast is extremely refned. Te cement is soft like velvet but also has a polished refective surface. In every step of the casting process, Ando

FIGURE 2.27 The concrete volume inserted in Punta della Dogana. Photo: Xuancheng Zhu.

86

How Do We Cast?

invests in achieving a desired material quality. A specialized lab tested ratios of concrete ingre­ dients to determine an exact cement mix. Producing a fawless surface requires a formwork system with calculated details and expert craftsmen to execute precise casting procedures. Te formwork is made of multi-layered birch and the wood was replaced with every concrete pour to prevent warping in the formwork. Te assembly of formwork was highly precise with a one-eighth of an inch (3mm) construction tolerance. Te joints between formwork panels are very subtle like fne lines etched into the cement. Tere are no visible inconsistencies in the casting. Te surface quality completely defes and challenges the notion that cast cement or concrete can only be rough and industrial.

Atypical Formwork Strategies So far, our casting discussions have characterized formwork as construction components that are temporary and tossed aside once the construction is done. Often, the formwork or mold costs more to build than the cast material itself. Te formwork material may have a limited lifespan in forming casts. And if the formwork is an on-of design, it may not be reused, con­ tributing to construction waste. In the following projects, we will look at projects that found alternative functions for the formwork. In the case of Shoei Yoh’s Naiju Community Center and Nursery School, the formwork for the cast concrete roof is not removed, but instead the formwork becomes a surface feature of the building interior. Yoh was a pioneer in early 3D modeling tools and he used the computer to generate the Community Center’s form in 1994. Te building’s roof was a continuous fabric-like surface that foated of the ground. Folds in the roof lifted up to supply natural light and defned access into the building. Te top of the building tapered up and formed a skylight at the top. Te roof lifted up at its corners to reveal the inner surface of bamboo slats displaying a continuity of surface into the building. Te roof is a cast concrete construction that is square in plan and shaped like a tent. Te Naiju area in Japan is known for its expertise in bamboo caning, so Yoh used bam­ boo as the supporting formwork for the concrete casting. To create the free-form roof shape, fexible bamboo slats were woven into a lattice structure. Te square bamboo lattice draped of a temporary post in the center of the building. Te construction process of the project was straightforward in concept, so the members of the community could build the lattice and trowel viscous concrete onto the formwork. Once the reinforced concrete hardened, the formwork was not removed. Instead, the bamboo framework defned in the interior space of the building and this major structure in the casting process was revealed within the space. It is also interesting for us to recall Shigeru Ban’s Center Pompidou-Metz from Chapter 1 and compare it with Shoei Yoh’s project. Both buildings have similar building geometries and forms and both have a woven wood lattice structure that supports the pri­ mary roof material. However, they are achieved through two completely diferent materials and assembly operations. It is important for us to acknowledge that we can execute the same building shapes in various materials and methods. However, the spatial efects of the materi­ als and construction operations afect the perception of and experience within the building. Te casting formwork does not need to be a separate assembly or structure. In the Teshima Art Museum, Ryue Nishizawa shapes the land to be used as the formwork for the

87

Why Cast?

concrete structure (Figure 2.28). Tis practice is uncommon, but the engineer, Heinz Isler, frst experimented with earth mound formwork for a bomb shelter in 1955. Te Teshima Art Museum is a reinforced concrete shell that is 14.7 feet high (4.5 m) and 9.8 inches thick (25 cm). During the construction, the contours of the land are altered to act as formwork for the concrete shell. In order to shape the ground with precision, Nishizawa provided 3,500 points of measurement for the casting operation. Once the new topography was formed, a bed of mortar coated the contours and then concrete’s steel reinforcement was set in place. To achieve a pure white and smooth concrete cast, Nishizawa used a concrete mix with white cement and a lime additive. Within one day, the concrete was poured and troweled. Te concrete cured for fve weeks and then earth was removed from inside the structure. Te exterior surface of the concrete received an application of water-repellent coating. Te interior of the cast concrete was polished to further refne the smooth surface (Figure 2.29). Typically, our understanding of insitu and precast concrete is associated with the quality of the cast and with specifc assumptions regarding assembly strategies. If we want highly detailed and refned surfaces, we would opt for precast components fabricated in con­ trolled conditions. Te precast components are then transported to the construction site and fastened to support structures. However, insitu casting does not preclude the possibility of achieving high quality casts. As demonstrated by Ando’s work, concrete cast on site can be exquisite in texture and surface quality. As with all our building constructions, we rely on composite assemblies of mate­ rials. Not all casting operations are categorized as either insitu or precast. Te following two projects use interesting composite construction processes incorporating both precast and

FIGURE 2.28 Teshima Art Museum used the topography as the concrete form. Photo: Epiq [CC BY-SA 3.0 (https:// creativecommons. org/licenses/by -sa/3.0)].

88

How Do We Cast?

FIGURE 2.29 Interior space of the Teshima Art Museum. Photo: Epiq [CC BY-SA 3.0 (https:// creativecommons. org/licenses/ by-sa/3.0)].

insitu methods to achieve the desired design efect with cast materials while also minimal­ izing the amount of formwork materials. Te wall assembly of Cukrowisz Nachbar’s Voralberg Museum Addition uses a site-cast technique that casts a detailed façade with the precision of precast panels and an efcient use of formwork. Te concrete façade has an array of studs patterned across the smooth and refned surface (Figure 2.30). Te relief of studs produces shadows giving depth and texture to the façade. Upon closer inspection, the studs reveal they have intricate details, like fowers, that are cast from a range of plastic (PET) bottle bottoms. Cukrowisz Nachbar uses a familiar everyday object and changes our perception of the object itself. Te PET bottle bottom is shaped to provide structural strength for plastic against the weight of liquid. Te PET bottle typically holds liquid upright and the bottom is obscured, but in this façade, the bottom of the bottle is highlighted in a vertical surface. Te construction of the Voralberg Museum Addition consists of a cast-in-place concrete load-bearing construction, rigid insulation attached to the load-bearing wall, and then the façade surface is cast insitu over the insulation. Te casting of the façade uses the assembled rigid insulation and the load-bearing concrete wall as one side of its formwork.

89

Why Cast?

FIGURE 2.30 Concrete façade at the Voralberg Museum Addition. Photo: Lisa Huang.

Te architects designed the façade with repetitive panels using two standardized patterns. Fabricators cast a silicone mold for each of these two panels. Tese two silicone forms were brought to the construction site and set into a steel formwork structure. Te entire façade uses these two forms so the casting process occurs in sections. Te rigid insulation is attached to the cast-in-place concrete structure and then steel reinforcement is set in place. Te silicone formwork tilts into position and is flled with cement mix. Te viscosity of the cement mix is extremely important to make sure that each of the protruding fowers is completely flled with cement mix. Once the cement mix sets, the silicone mold shifts over and the casting process repeats. Te façade is cast in sections, but the overall efect is of a continuous and smooth concrete surface. Te details of the studs are precise and refned (Figure 2.31). Te casting process and the formwork assembly are pro­ duced with control. Site casting the façade in sections, instead of precasting panels, reduces the need for additional structure or fasteners and also eliminated the need to transport panels from factory to construction site. For the Palazzetto dello Sport in Rome, the architect, Annibale Vitellozzi, col­ laborated with the engineer, Pier Luigi Nervi, who developed a construction method for the arena’s roof that integrated both precast and site-cast concrete. Tey designed a cofered dome roof spanning over a 3,500-seat capacity arena for the 1960 Olympics basketball games (Figure  2.32). Te use of both structural prefabrication and site-cast

90

How Do We Cast?

FIGURE 2.31 Detail of studs in the concrete. Photo: Lisa Huang.

concrete was an innovative approach that emerged from economic constraints and lim­ ited resources in Italy at the time of construction. Te standard approach for forming the dome roof would require a complicated formwork and a large quantity of wood that could not be reused. Te use of reinforced concrete would work best for the 200-foot-long span roof but steel was imported into Italy, so it was a limited and expensive resource. Te construction of the dome had to be as efcient as possible in cost and erection time. Trough these imposed limitations, Nervi invented numerous patents for the concrete construction process. Te structural design of the dome is a series of ribs that cross each other resulting in a pattern of diamond cofers. Te dome was supported by 36 Y-shaped trestles cast in-place (Figure 2.33). Nervi’s innovative strategy was to break down the dome into smaller buildable components. Te concrete shell was composed of 1,620 prefabricated diamond-shaped panels that were all cast on site. Tese panels were then set in place using a reusable metal scafolding (Figure 2.34). Ten high-strength concrete was cast in the web between the diamond panels integrating all the components into one roof structure. Te concrete Nervi used was his invention called ferrocemento. Layers of chicken wire mesh were used as reinforcement instead of conventional steel reinforcement. Nervi also adjusted the concrete mix so that it was high strength and could be poured at a mini­ mum thickness of one inch (2–3 cms). Nervi’s concrete composition was inexpensive and

91

Why Cast?

FIGURE 2.32 Palazzetto dello Sport interior of the concrete structure. Photo: Kazuyo Oda.

FIGURE 2.33 Palazzetto dello Sport exterior. Photo: Kazuyo Oda.

92

How Do We Cast?

FIGURE 2.34 Construction of the roof using precast concrete panels. Photo: unknown photographer. Photo from Italy. CC there has expired.

easy to form. Tis construction method also allowed the panels to be thinner, thus lightening the weight of the roof. Te edge of the dome was corrugated to give greater structural rigidity in connecting with the Y-shaped trestles. On the construction site, the production of the precast components occurred simultaneously with the site excavation and the erection of the foundational structure. Te prototypes for the 13 diamond cofer shapes were built in wood. From these wood prototypes, they produced ferrocemento molds that would then be used to produce the fnal ferrocemento cofer components. Te edges of each cofer form were also shaped to form the structural ribs. Each mold was small enough to be managed by a few people and each precast component was light enough to produce a large quantity of components each day. Te construction of the arena was extremely efcient and rapid that the dome was constructed in 40 days. An important concept that we must acknowledge is that limitations imposed on our design projects provide opportunities for innovation. In each of these case studies, the building design and the atypical construction methods respond directly to limitations imposed by local conditions and resources. Tese projects found intersections between con­ ventional construction operations in order to maximize efciencies in the building process. It is critical for us to understand typical modes of construction practices, but we cannot let the fear of atypical processes and straying from comfortable practices limit our design intentions.

93

What Happens When Casting?

What Are the Failures/Limitations/ Problems We May Encounter? Casting is an operation that is dependent on a removable assembly – the formwork – to give shape. Additionally, the cast material transforms from liquid to solid during the construction process. We do not know exactly what the resulting cast will look like until the formwork is removed. In the case of concrete, the material cannot return to its original viscous state, so the cast material bears the scars of any inconsistencies or missteps in the construction process. Any cast material’s surface appearance is afected by the craft of the formwork. A formwork with texture or imperfections will certainly imprint onto the cast surface. Most castable materials are uniform in their material composition; however, since concrete is a mixture of ingredients, there is more potential for inconsistencies. Consistency in casting concrete has a wide range of results. Concrete is an unforgiving material in that concrete records any missteps in the construction process. Tese inconsistencies would not be visible until after the material has solidifed and the formwork has been removed. By that time, it is too late to correct these issues. Since concrete is the most prevalent building material used around the world, the majority of our case studies in this section will focus on concrete.

STUDENT EXPERIMENT What Are Some Missteps Tat We Confront in the Casting Process? Materials and Methods of Construction Project | University of Florida For this lab project, students in the course were required to cast a 3-inch thick concrete slab that included a surface texture and an aperture. Te students directly confronted the factors in casting concrete and the material’s characteristics and behaviors that emerge during the casting process.

94

2.3

What Happens When Casting?

Making a mold: Wood, metals, and plastics were used for formworks and each material yielded diferent results. Formwork materials that did not absorb water produced smooth surfaces in the cast. When wood formworks were not sealed, the con­ crete casts resulted in dusty and sandy surfaces. Te water in the concrete mix was absorbed into the wood, so it prevented the chemical reaction between water and cement against the wood surface. Te formwork also had to hold up to the pressures from the concrete in its viscous form. Although the cast concrete slabs were small, in some cases, students had to construct reinforcing structures for the formwork. Te concrete mix imposed forces on the formwork and looked for areas of weakness where the viscous mix could seep through seams. Creating consistency: Concrete surfaces picked up all kinds of imperfections from the casting process. If there was not proper mixing, pouring, or agitation, then air bub­ bles were trapped against the formwork or aggregate was exposed creating pockmarks. Te result produced rough edges, honeycombing, or jagged corners (Figure 2.35). Te exposed concrete surfaces at the top of the formwork had to be troweled smooth like in the process of casting concrete foor slabs. Waiting between casts: Concrete will shrink as it cures. If students did not mix enough concrete and then waited a day later to mix new concrete, the casting revealed a cold joint where the break between concrete pours was visible on the surface of the con­ crete. It was impossible for the students to add concrete to correct the concrete cast surfaces without the appearance of a cold joint (Figure 2.36). Once the frst concrete mix started to cure and depending on the time frame in between pours, the concrete

FIGURE 2.35

Rough edges of cast concrete from removing the formwork. Photo: Lisa Huang.

95

Why Cast?

FIGURE 2.36

Cold joint from pouring concrete on top of curing concrete. Photo: Lisa Huang.

could pull away from the form. Ten any added concrete mix could slip between the formwork and the earlier cast. Concrete is an unforgiving yet honest material because it revealed everything from the construction process. Avoiding breaks and cracks: Te formwork design and the sequence of removing formwork added unnecessary forces onto the cast concrete. Te students had trou­ ble with reentrant corners when they had complex formwork designs. Tese reen­ trant conditions would bite onto the concrete and the formwork was difcult to disengage. Removing the formwork for any apertures in the slab also proved to be difcult, especially if the releasing agent was not applied consistently. Te forces applied in removing stubborn formwork would impose too much pressure onto the concrete slabs. Variation in the concrete thickness and internal corners cre­ ated vulnerable points in the concrete which often resulted in cracks in the cast (Figure 2.37).

96

What Happens When Casting?

FIGURE 2.37 Huang.

Cracks in the concrete at changes in concrete shape and thickness. Photo: Lisa

Precision and Control: How Do We Accommodate or Outsmart Inevitable Inconsistencies in the Casting Process? We should expect that imperfections and irregularities will appear in cast concrete. In cast­ ing, if we anticipate the steps in the process ahead of time, we can produce better results and minimize imperfections. What we want to see in the cast assembly afects the casting operation. If we want to minimize inconsistencies, perhaps we should pursue precasting to improve quality control. If we want to site cast, then we have to be concerned about the construction process with the formwork assembly, the concrete mix, and the installa­ tion process to ensure better quality. In this section, we are interested in case studies that used strategies to disguise, hide, or minimize the appearance of imperfections in casting concrete. In its viscous form, concrete conforms to any given shape. But once it sets, con­ crete is difcult to drastically change and alter. It is what it is. Concrete is an obstinate mate­ rial at the building component scale; it is not only unforgiving, but also unyielding. It is not going to move and we cannot dissemble and reassemble it. We have to visualize the operations of the cast form and its complementary design formwork to forecast our fnal result. Once concrete solidifes, we can alter its fnish appearance, for instance, by polishing or bush ham­ mering its surface. But most of these fnish treatments can be time consuming and expensive. Te beauty of the casting operation is that a single material solidifes into a predetermined shape and form. And the formwork, the inversion of the cast, can provide spatial depth in the concrete surface.

97

Why Cast?

For the Unite d’Habitation in Marseille, Le Corbusier frst drew attention to designing the casting formwork in order to manipulate the surface texture of concrete (Figure 2.38). Tis was Le Corbusier’s frst project where the building was cast insitu with exposed reinforced concrete. Before the Unite d’Habitation, Le Corbusier mostly worked in white materials, deemphasizing the materiality of building components. Tis building, how­ ever, marked the beginning of expressing beton brut. Le Corbusier embraced bare rough cast concrete and celebrated the imperfections and the stubbornness of concrete. In the case of Unite d’Habitation, the concrete was directly cast in place and no alterations to the concrete were made after the formwork was removed. Le Corbusier’s acceptance of beton brut was a result of the limited resources and the needs of the time period. Unite d’Habitation, completed in 1952, was commissioned after World War II. At this time, there was a desperate need for housing in Marseille and concrete was the least expensive building material option. Using rough and monolithic con­ crete was also signifcant in reinforcing Le Corbusier’s idea to design a multi-family housing building that embodied a vertical city. After the war, skilled builders were also far and few between, so craftsmanship and experience working with concrete were limited. To mitigate the expected imperfections and undesired efects in the cast concrete, Le Corbusier integrated a surface pattern using an arrangement of rough wooden boards that worked in harmony with the coarse concrete (Figure 2.39). Te superimposed texture and pattern intended to draw attention away from any visible faws in the cast concrete. Te added pattern of the rough wood boards also provided a texture relatable at the human scale for the monolithic concrete building. Since concrete is a typically rough material, over time, it picks up everything on its surface. Weathering in conjunction with all the textures and imperfections on the concrete surface creates opportunities to collect water, dust, and dirt. Concrete turns into a FIGURE 2.38 Concrete texture at the Unite d’Habitation. Photo: Lisa Huang © F.L.C. / Adagp, Paris, 2019 sauf pour l’église de Firminy:© F.L.C. / ADAGP, Paris [année/year] et José Oubrerie [Conception, Le Corbusier architecte, José Oubrerie assistant (1960–1965). Réalisation, José Oubrerie architecte (1970–2006)] et pour la Chapelle Notre Dame du Haut à Ronchamp: © ADAGP, Paris [année/year].

98

What Happens When Casting?

FIGURE 2.39 Construction of the cast concrete formwork at Unite d’Habitation. Photo: Photographie Industrielle du Sud-Ouest © F.L.C. / Adagp, Paris, 2019 sauf pour l’église de Firminy: © F.L.C. / ADAGP, Paris [année/year] et José Oubrerie [Conception, Le Corbusier architecte, José Oubrerie assistant (1960–1965). Réalisation, José Oubrerie architecte (1970–2006)] et pour la Chapelle Notre Dame du Haut à Ronchamp: © ADAGP, Paris [année/year].

stone-like material and throughout the material, there are very small pores that result from the curing and hydration process. Water may absorb into the cured concrete, but it does not necessarily permeate through the concrete. Weathering can quickly age the appearance of concrete, so it requires maintenance to keep the surface clean. If water penetrates into concrete cracks, then we would be most concerned that fuctuating temperatures would freeze and thaw any trapped water and it could ultimately cause cracking and structural problems in the concrete. Sealing the concrete is one strategy to prevent water and dirt from absorbing into the concrete. However, at the Yale University Arts and Architecture Building, Paul Rudolph addressed the issue of weathering by casting reinforced concrete and then bush hammering vertical ridges to manage water and disguise the gathering of dirt. Te concrete was cast with a continuous pattern of vertical grooves and ridges as a surface texture. After casting the reinforced concrete, the protruding ridges were knocked manually by hammers to reveal stone aggregate cast in concrete (Figure 2.40). Te rough appearance of its cast concrete is largely associated with Brutalist architecture. Rudolph’s strategy of revealing the aggregate created added depth and contrasting shadows on the surface to hide weathering stains on the concrete. Te vertical grooves and ridges were cast into the concrete and provided a large scale of depth and shadow (Figure 2.41). While the aggregate was revealed from bush hammer­ ing the concrete, it added another scale of texture and shadows to the building. Tis pattern and texture has become the standard for disguising weathering in concrete, but this concrete texture also had the disadvantage of looking too rough and brutal. Herzog & de Meuron also used an alternative strategy to expose aggregate at Schaulager in Basel. At this monolithic museum building, the aggregates in the cast con­ crete are exposed by removing uncured cement at the surface of the cast (Figure 2.42). Te

99

Why Cast?

FIGURE 2.40 Bush hammered cast concrete at Yale Art and Architecture building [Art and Architecture Building, Yale University, New Haven, Connecticut. View of fnished con­ crete surfaces].

FIGURE 2.41 Formwork and con­ crete casts during the construction of Yale Art and Architecture build­ ing. Photo: Scutt, Der, photographer.

concrete mix used an aggregate of pebbles that were excavated from the museum’s site. A retarding agent was applied to the formwork lining and it kept the cement against the formwork from hardening. Te formwork was removed and the concrete on the exterior surface was still soft. Te cast concrete surface was then power-washed and loose particles manually hammered to reveal the pebbled aggregate at the surface of the concrete (Figure 2.43). To seal the concrete and prevent water penetration, the concrete mix included mica to produce a non­ porous silty concrete material. It is also interesting for us to note that in the exterior surface of the concrete, we can see traces of the joints between the formwork panels. Tis subtle grid

100

What Happens When Casting?

FIGURE 2.42 Concrete façade with exposed aggregate at Schaulager. Photo: Lisa Huang.

FIGURE 2.43 Concrete surface detail. Photo: Lisa Huang.

breaks down the scale of the massive concrete façade. Where the formwork panels abut one another, the concrete mix lost additional water content which prevented additional cement from curing. To create the rough aggregate surface at Schaulager, any imperfections or faws in casting are controlled through a precise and complex manipulation of the concrete mix, the formwork, and the casting construction process.

101

Why Cast?

As we discussed in the above examples, we should anticipate inconsistencies and imperfections in site-casing concrete. Tese imperfections do not need to be seen as negative, but in fact, we can use them to our advantage. In the SOS Children’s Villages Lavezzorio Community Center, Studio Gang uses cold joints as a feature of the building façade design (Figure 2.44). Cast concrete is not seamless when there are long breaks between concrete pours. Typically, buildings using cast concrete would have concrete mixers lined up one after another to cast a continuous concrete surface. If the casting process must accommodate long breaks in between pours, the cast concrete will already start curing and a visible lift line or cold joint appears between those casting pours. Built for a social services organization on Chicago’s South Side, the Community Center was constructed using a large number of donated building materials, products, and services. Many of the donated materials were left over from other projects from the Chicago area. In this two-story building, a minimum of two concrete pours would be needed to form the main exterior wall and there was no guarantee the donated concrete mixes would occur all at once. Studio Gang could not assume that the cast concrete could be a continuous pour. Terefore, a visible cold joint between pours was to be expected. Tis imperfection became the impetus for the façade design (Figure 2.45). Studio Gang developed a strategy to empha­ size the cold joint, and thereby the fuid nature of concrete, by deliberately multiplying the pours, incorporating color variations to diferent concrete mixes, and working with skilled tradesmen to achieve a certain level of ‘waviness’ in the fnal wall by predicting variation in elevation between sequential pours. Tey alternated the concrete pours using three colors – standard gray concrete, a black color additive, and a white Portland cement additive. Studio Gang studied the use of three concrete color variations and diferent slump ratios through plaster models which helped to convey the façade concept to the contractor (Figure 2.46). Te plaster studies tested the visual potential of using diferent pours of con­ crete with diferent properties, including varying levels of viscosity, to construct the wall. In their studies, and in fnal building, the façade further expresses the fuidity of concrete as

FIGURE 2.44 Cast concrete façade of SOS Children’s Villages Lavezzorio Community Center. Photo: Leslie Fiedler.

102

What Happens When Casting?

FIGURE 2.45 Cold joint detail in the façade. Photo: Leslie Fiedler.

FIGURE 2.46 Physical models of the cast concrete façade concept. Photo: Courtesy of Studio Gang.

103

Why Cast?

part of the building appearance. Te cold joints were inevitable in the façade, so Studio Gang emphasized undulation in casting of concrete – permanently capturing the process of the wall’s construction and the skill of the tradesmen who poured and fnished it. Te viscosity of a concrete mix will typically level itself once it is poured and agi­ tated. However, because the donated concrete was not guaranteed to be the same in viscosity, the concrete mix needed to be a low-slump, thicker slurry, in order to achieve greater height variations in the diferent concrete casts. Low-slump concrete mixes will resist leveling even when it is vibrated. After the forms were removed, the concrete surface was lightly sand­ blasted to remove small imperfections. Since they had to rely on donated building construc­ tion materials, Studio Gang demonstrated fexibility and adaptability in design thinking which led to an innovative design approach in controlling casting imperfections. Another approach to outsmarting casting imperfections is to be intimately involved during the construction process. However, the architect does not usually have the luxury of directly working with the casting operation. As it is well known, Carlo Scarpa worked very closely with fabricators in his building projects to ensure a higher level of construction craftsmanship and precision. At Brion Cemetery, the cast concrete structures were intricately detailed in its concrete cast form (Figure  2.47). Troughout the Brion

FIGURE 2.47 Brion Cemetery chapel interior. Photo: Lisa Huang.

104

What Happens When Casting?

complex, the concrete was cast with undercuts and tight reentrant corners which can cre­ ate challenges in the construction. Te concrete forms required extremely complex formworks which are difcult to control with an obstinate material like concrete. Scarpa worked closely with craftsmen on the construction site, and as we have discussed, sharp corners or smooth top surfaces were at the mercy of trapped air bubbles and aggregate size in the concrete mix. Te more complex the formwork, there is a higher possibility of producing imperfect edges and corners. Brion Cemetery is a complex of continuous cast-in-place concrete structures within a landscape. Te concrete cast is formally complex in that is it detailed throughout with stepped ziggurat patterns (Figure 2.48). In order to form the stepped ziggurats, the formwork or shuttering must be enclosed on all sides making it difcult to remove all bubbles from the concrete surface. Even more complex is envisioning the negative of the concrete form, with all its details, as a formwork. At Brion Cemetery, the cast concrete is an intricate design stepping back and forward from the primary concrete face. Te formwork would require shuttering on more than its two bounding sides, thus creating numerous undercuts. When we look closely at the cast concrete at Brion, we can see traces of the hori­ zontally oriented wood slats in the formwork. Te reentrant corners do not reveal an overlap between the wood slats constructing the corner, so the wood was likely mitered to shape the corners and edges. As a single formwork, the stepped ziggurat was a blind cast in concrete. Te concrete slurry needed to get in all corners of the formwork. Te quality of the cast con­ crete could be seen until the formwork was removed. Once the cast was revealed, we could see the places where the concrete pour did not reach. Te concrete surface of the chapel’s exterior expressed the horizontally oriented wood slats used as casting formwork (Figure 2.49). Te dimensions of the ziggurat dimensions were not always in sync with the dimension of the

FIGURE 2.48 Exterior detail of the ziggurat. Photo: Lisa Huang.

105

Why Cast?

FIGURE 2.49 Concrete surface displaying formwork traces. Photo: Lisa Huang.

wood slats. Te ziggurat pattern both protruded from and receded into this exterior concrete surface. Te protruding and receding ziggurats created shadows that interrupted the horizon­ tal banding of the wood formwork and they produced opportunities for inconsistencies in the casting process (Figure 2.50). If we imagine the formwork assembly for the protruding ziggurat, we would notice deep ledges where concrete needs to fll in. For the receding ziggurat, the wood formwork may swell and become difcult to remove especially at its smallest and deepest recesses. In order to cast concrete with so much detail and changes in geometry, the concrete mix must have a viscosity that levels easily and the formwork must be removed carefully. Every horizon­ tal concrete surface in Brion Cemetery required additional attention in the casting process. However, even with a high attention to craft, it is impossible for a complex geometry for cast concrete to be perfect. It is extremely difcult to produce sharp convex and concave corners in casting without the risk of breakage or inconsistency in edges. Te ledges in the ziggurat

106

What Happens When Casting?

FIGURE 2.50 Detail of the wood form against dimensions of zig­ gurat. Photo: Lisa Huang.

details are prime locations for air bubbles to gather between the concrete and the formwork (Figure 2.51). We can outsmart imperfections in casting by acknowledging the nature of the cast­ ing process and anticipating the behaviors of the material being cast. We need a solid material understanding in order to get the most out of an assembly operation. It is well documented that Scarpa intended for Brion Cemetery to appear as a ruin. Te complex concrete casting invites increased weathering of the building material. Te ziggurat recesses and protrusions encourage accumulation of water stains, dirt, and leeching in the concrete. Tis foresight and awareness of cast concrete behaviors further enhances the character of Brion Cemetery as a ruin. Scarpa challenges the intricacies of forming and casting concrete, but also the smaller scale of details helps mask imperfections in the casting. Scarpa uses metal and tile details as edge banding for the concrete to accent the concrete edges, to help protect its corners, and to disguise its irregularities. Instead of concrete being a massive monolithic surface, the intrica­ cies of cast details divert attention away from the need for perfection (Figure 2.52).

107

Why Cast?

FIGURE 2.51 Bubbles cast on the surface of the concrete. Photo: Lisa Huang.

108

What Happens When Casting?

FIGURE 2.52 Tiles embedded into the edge of cast concrete wall at Brion. Photo: Lisa Huang.

STUDENT EXPERIMENT How Do We Control Material Behavior in the Casting Process? Calvin DiNicolo | University of Florida Calvin was interested in casting metals and seeing products like expanded aluminum panels piqued his curiosity regarding other methods to manipulate molten aluminum. Working with aluminum was also more feasible than other metals because aluminum has a lower melting point. Calvin made his own crucible and furnace to melt salvaged aluminum for these material tests. Learning how to work with the cast material: In his frst steps, Calvin researched the various conventional methods of casting metal such as the sand casting and the lost wax methods. He needed to understand the standard ways of working with cast metal through experimenting and developing his casting techniques. His early attempts

109

Why Cast?

FIGURE 2.53

Aluminum casting experiments in techniques. Photo: Calvin DiNicolo.

at sand casting and lost wax were rough but Calvin kept making new versions and consequently he refned his skills in these standard casting strategies (Figure 2.53). Developing a process of discovery: Once Calvin understood conventional metal cast­ ing operations, he then started thinking about other ways to work with that knowl­ edge. As in any research process, Calvin constantly questioned empirical results and asked “what if?” in order to determine his next steps. Tese questions helped him develop strategies that were rooted in standard operations, but then strayed from conventions. Te experiments in lost wax motivated Calvin to think about what other mold materials could be melted or burned away. Sand casting provoked him to think about allowing the form some freedom. He preferred unpredictability when producing openings in the cast aluminum test panels (Figure 2.54). Narrowing into a strategy and then trying everything possible: Calvin then focused on a single question and developed strategies for casting metal panels to catch light on its surface and within the panel itself. He was interested in how light changes the appearance of the panels. In his research and experiments, he determined desired qualities – perforating the panel, catching light between the surfaces of a panel, and random patterning so each panel is unique. He tried numerous atypical casting operations to answer the questions of what materials can burn away, what materials release easily from cast aluminum, and how to control the opening size. Te process of discovery led him to casting aluminum using ice and dry ice. Te reaction between molten metal and ice also created two diferent surfaces for the cast aluminum. Te molten metal not only melted the ice but consequently produced steam. One sur­ face has rounded edges in interaction with ice and water while the opposite surface exposed to air and steam has wispier, thin, and rougher textures. With each experi­ ment, he was building knowledge in understanding the material’s behavior and then the ways to control the material to produce diferent efects with changing light conditions (Figure 2.55).

110

What Happens When Casting?

FIGURE 2.54

Initial tests of casting with ice. Photo: Calvin DiNicolo.

FIGURE 2.55

Light against the surface of the cast aluminum panel. Photo: Calvin DiNicolo.

111

Why Cast?

Texture and Unpredictability: How Do We Turn Surface Inconsistencies or Defects into Design Features? Tere is no denying that concrete is typically considered a rough and industrial material. Concrete picks up everything from the formwork and the casting process, so there is a lot of pressure placed on the quality of the formwork. Tere will always be irregularities and blemishes in a concrete cast. Te role of cast concrete is most commonly as a structural mate­ rial that supports more refned fnish materials. Concrete is not always desirable as a façade material because of its industrial appearance. But since concrete can pick up detail, there are strategies to make concrete an elegant and refned material. As we have seen in the previous section, we can superimpose textures or patterns to draw attention away from blemishes. But also, like Ando’s Punta della Dogana, we can perfect the concrete mix and the fabrication process to achieve fawlessly smooth concrete casts. Tis requires a great deal of experimenta­ tion and applied testing to control desired results. In casting concrete, we know that the material can misbehave and imperfections are inevitable. It requires a certain amount of testing to know how to control the cast mate­ rial’s behavior. Tere are numerous factors and intricacies in the casting process that can afect the fnal product. We are not solely dependent on the mold or formwork because we can also further manipulate the surface of the cast product. Tere is also beauty in the socalled ‘defects’ in the casting process and we can embrace these imperfections as perfection. To make the unintentional intentional also requires persistence and taking risks in producing desired results. In this section, we are interested in projects that have highlighted potential imperfections in the casting process as an advantage or a feature for the building. As discussed, the inevitable imperfections associated with the casting of concrete is typically undesirable. However, for the American Folk Art Museum, Tod Williams Billie Tsien Architects intentionally reproduced concrete’s rough and unpredictable texture using cast metal for the façade. Te metal cladding was cast in Tombasil, a type of white bronze and this was the frst application using it as a building material (Figure 2.56). Tombasil is an alloy with 57% copper content and it was a typical material for fre nozzles and ship propellers. At the top of the building, the façade had a diagonal fold in the cast panels and a break in the façade. Te façade tilted in plan to include vertical apertures (Figure 2.57). Te 63 metal façade panels were staggered in horizontal bands using three diferent panel widths. None of the façade panels were identical. Te surfaces of the cast bronze panels were mottled and cracked and each panel was cast with unique texture. For the American Folk Art Museum, Williams Tsien closely collaborated with Polich Tallix, a metal foundry, who also cast the aluminum fences at Herzog & de Meuron’s 40 Bond Street building. Williams Tsien wanted the cast bronze to imitate the imperfec­ tions that are typical in cast concrete and they did not want each panel to be unique. Metal does not behave exactly the same as concrete when it is cast. Because the metal is molten, it solidifes as soon as heat is lowered or removed. So together, the architects and the fabricators researched and experimented with strategies to intentionally cast imperfections in the bronze. Tis was not an easy task. Te surface quality of cast metal and cast concrete difer based on their materials characteristics. In concrete, these inconsistencies can happen at any point in the casting process and these inconsistencies are unpredictable. Cracks in concrete usually occur when there are signifcant changes in thickness or geometry of the concrete.

112

What Happens When Casting?

FIGURE 2.56 Cast bronze façade of the American Folk Art Museum. Photo: Detlef Schobert.

Producing cast metal with cracks or color diferentials depended on manipulating factors in the casting process. Tey were trying to achieve qualities of inconsistencies that naturally appear in cast concrete, so they were working against the nature of cast metal. Both cast metal and cast concrete also required very diferent materials for formwork. Trough an extensive discovery process, the architects and the fabricators developed a method using a steel surface and a concrete surface as the formwork. Tey were able to produce cast metal panels that varied in their mottled surface (Figure 2.58). Te fnish surface of bronze panels had cracks, air bubbles, and all kinds of wrin­ kles providing texture that helped the panels catch light. Te bronze texture reacted to natu­ ral light and changed its color and appearance throughout the day. Te metal panels were not all uniform. Te refective metal fnish in combination with the surface texture variations produced a dynamic surface with spatial depth. From the casting process, the metal panels also had varied tones between the panels and within a panel itself. Te color variation was marbled and non-uniform, so that added an implied depth in the bronze. It is interesting for

113

Why Cast?

FIGURE 2.57 Apertures in the façade. Photo: Kazuyo Oda.

us to note the multi-scalar qualities of the American Folk Art Museum façade. At the scale of the building, the folds and displacement created windows and entrances. At the scale of the components, the panel pattern ran horizontal on a proportionately tall vertical façade. And at the detail scale, the inconsistencies and texture of each panel addressed a tactile experience. To create the concrete texture inside the Bruder Klaus Chapel, Peter Zumthor used an unusual formwork and process of casting. He shaped the formwork by using 112 local pine tree trunks that aligned side by side to form the interior of the chapel. Each pair of pine tree trunks were vertically oriented and assembled into triangular arches starting from the chapel entrance and extending to the aperture at the top of the chapel. Layers of concrete were then poured and then rammed around the wood formwork. Once the concrete set, the tree trunk formwork was burned away. As a result, the burned wood form left behind a charred surface on the concrete and an added sensory dimension to the chapel interior (Figure 2.59). Te concrete material rammed against the wood formwork created surface texture that is rugged and random in its surface appearance. No exterior formwork was used because the concrete had a dense viscosity and it was troweled into shape on the exterior. Te concrete

114

What Happens When Casting?

FIGURE 2.58 Detail of the cast bronze texture. Photo: Kazuyo Oda.

was mixed with local sand and gravel and cold joints are visible on the exterior (Figure 2.60). Each visible layer was the amount of concrete constructed in a day’s work. Te concrete was cast onto the tree trunks and resulted in an interior surface of ragged fns. Concrete is non­ combustible, so the cast form in combination with what the concrete absorbed in the burn­ ing process produced unpredictable surface colors and textures. It is also interesting that the wood piles created the interior shape for the chapel and the concrete formed around it. Tis is the inverse of the typical casting process where formwork bounds and surrounds the cast material. Instead, the Bruder Klaus formwork was only on the inside creating the occupiable space instead of the usual formwork determining the exterior building form. Te contrast between the smooth concrete against the wood trunks and the inconsistent fns between the trucks establishes a beautiful texture in the concrete (Figure 2.61). In regard to texture and unpredictability, the Clyford Still Museum by Allied Works is a fascinating example of celebrating the potential defects and problems in concrete casting and turning them into an impactful aesthetic feature for the building. Te struc­ ture, enclosure, and the facades of the building are cast-in-place concrete (Figure 2.62). Te

115

Why Cast?

FIGURE 2.59 The interior sur­ face of concrete in Bruder Klaus Chapel. Photo: Lisa Huang.

FIGURE 2.60 The exterior of Bruder Klaus and detail of rammed concrete. Photo: Lisa Huang.

116

What Happens When Casting?

FIGURE 2.61 Formwork residue on the concrete. Photo: Lisa Huang.

building has two components – the wall texture and the ceiling screen – that cast concrete in unique ways. Te wall texture focused on unpredictability in casting to create texture, while the ceiling screen created texture using precision of digital fabrication. Te ceiling screen for the Clyford Still Museum will be discussed in the next section. For the exterior and interior walls, the concrete was cast continuously for the full height of each section of wall. Tis was achieved through a combination of appropriate formwork design and a carefully choreographed pour sequence where the pour rate was slow enough to allow the concrete to set-up as the pour progressed. Tis was critical to prevent the concrete head pressure from exceeding the formwork’s strength capacity. Full height pour durations lasted between ten and 12 hours. Tis provided a seamless concrete cast that does not require tie rods or horizontal cold joints between concrete pours. Te vertical seams between wall sections are concealed due to the wood board spacing and vertical striations inherent in the formwork design. Te surface texture of the concrete consisted of thin vertical ribs formed by the spacing between linear wood boards. From a distance, the concrete surfaces dynamically play with light and shadow. Te vertical grain in the concrete texture is visible, but there is vari­ ation in the three-dimensional surface. Upon closer inspection of the concrete, the surface dynamism is attributed to randomly broken sections within each vertical rib (Figure 2.63).

117

Why Cast?

FIGURE 2.62 Concrete texture at Clyfford Still Museum. Photo: Lisa Huang.

Each concrete rib is not continuous and perfect in its form. Allied Works intentionally fac­ tored in the breaking point of concrete in the casting process as part of the design and expres­ sion of the concrete. Te tapered vertical ribs utilize the brittleness of the material and the tendency of thinner cross sections of concrete to chip and break of if subject to excess pres­ sure or impact. What makes the concrete extraordinary at the Clyford Stills Museum is that it embraced the unpredictability that exists in the casting process. Tey assumed that the concrete would break if it was cast into thin ribs. Allied Works took a huge risk in that all the thin vertical ribs could have broken of in the construction, but the possibility of ‘fail­ ure’ was incorporated into the design. To anticipate this irregularity, they had to test the concrete’s behavior with diferent formworks, consistencies, and strengths of concrete. How much unpredictability could be predicted? Allied Works is a practice interested in innovation and the process of discovery. At the Clyford Still Museum, they challenged the possibili­ ties within conventional construction processes in architecture. To determine the concrete surface texture, they produced a large number of material experiments in-house to develop

118

What Happens When Casting?

FIGURE 2.63 Details of Clyfford Still Museum concrete surface. Photo: Lisa Huang.

casting techniques and to test the factors that afect surface appearances. Tey tried atypical materials for formwork liners, chemical, or reactive efects on concrete, controlling the distri­ bution of aggregates, and variations in arranged wood formwork components. Trough this discovery process, Allied Works landed on a limitation of casting concrete that becomes the primary feature of the concrete building. Te vertical ribbed tex­ ture of the concrete façade is formed using vertically oriented fr wood boards of varying widths. In the gap between each board, the protruding rib is shaped by beveled board edges. Te notches forming the ribs were narrow enough that when the form is removed from the cast concrete, the architects understood that the ribs would likely break because con­ crete would be thin and brittle. Te design intention was to retain some vertical texture in the concrete surface, but the precise results of breakage in the formwork removal cannot be entirely predicted, only controlled through repeated testing and by working closely with the builders in the feld to ensure the process remained consistent throughout construction. Te width and the depths of the protruding ribs varied to ensure that the concrete ribs did not completely break of or remain entirely intact. Te design and casting process of the façade achieves a random three-dimensional patterning because it assumes breakage of concrete would occur during the formwork removal.

Texture and Exactitude: How Do We Make A Rough Material Look More Refned? In regard to concrete surfaces, we frst focused our discussion on disguising the casting imperfections, then the highlighting or valuing of those imperfections. We will now examine strategies that control the potential imperfections by altering and challenging the natural roughness of cast concrete. To elevate the characteristics of cast concrete requires eforts in maximizing precision from the material composition through to the removal of the formwork. As we saw in the cast concrete of Ando’s Punta della Dogana, the care in each step

119

Why Cast?

of the process produces unbelievably refned concrete surfaces. Te following case studies silence the ‘brutal’ qualities of concrete to produce refnement in the cast texture and form. Each project challenges the characteristic of typical cast concrete by working against the nature of typical cast concrete. One strategy for refnement emphasizes ornament through manipulating the range of textures possible in casting concrete. At the Eberswalde Technical School Library, Herzog & de Meuron imprinted pixelated photographic images onto the concrete. Te façade is composed of precast concrete panels and glass panels. Each panel depicts a screenprinted photographic image selected by the photograph artist, Tomas Ruf. Te concrete surface converted the black and white images into smooth and rough fnishes (Figure 2.64). Te small size of the image pixels required precision and contrast between those concrete textures. On the concrete, the image was produced using a flm liner and a retarder agent. Te screen-printed photograph has a black and white color range. Using a photolithographic process, the photo was set on a flm and a retarder agent was applied to the black colors of the image. Te flm then lined the inside surface of the formwork. Te retarder agent pre­ vented the cement from curing. As a result, the black parts of the image are rinsed away to remove the uncured cement. Because of the rough exposed aggregate and texture, the con­ crete remained dark gray in color. In contrast, the white parts of the image, that did not touch the retarder agent, are smooth and light gray. From a distance, the collective images create repetitive textures across the building façade. Looking closely at the concrete surface, we can see the composition of pixels that compose each image (Figure 2.65). Te width of the pixels varies to produce tones in between the black and white. Te precision of these pixels used the roughness of concrete to counter the brutal and rough appearance of concrete.

FIGURE 2.64 Precast and glass façade of the Eberswalde Technical School Library. Photo: Immanuel Giel [CC BY-SA 3.0 (http:// creativecommons. org/licenses/by­ sa/3.0/)].

120

What Happens When Casting?

FIGURE 2.65 Detail of the pixelized image. Photo: Immanuel Giel [CC BY-SA 3.0 (http://creativ ecommons.org/li censes/by-sa/3. 0/)].

In another Herzog & de Meuron project, the Tenerife Espacio de las Artes (TEA) addresses precision in texture at the large-scale perforations cast into concrete walls. On the exterior face of the concrete wall, the shape of the aperture is orthogonal and glass is inserted fush with façade (Figure 2.66). On the inside face of wall, the shape of the aperture has fl­ leted corners (Figure 2.67). Tis required a formwork that negotiated the geometry between the one face of the wall to the other. Although the concrete is monolithic, the concrete cast is refned in that the geometry of the apertures between the interior and exterior face require exact formworks, intricate internal structures, and precise edges. Te apertures through the concrete wall are not rectangular volumes, but instead they are complex geometries of varying lengths, widths, and shapes. Tey are arranged in a non-repetitive pattern derived from a pixelated image of the ocean. Te apertures do not stack or align with each other in any direction. Tis perforation pattern required a complex structure of steel reinforcement bars that were bent around each aperture. Te concrete was cast on site as a uniform construction using milled polystyrene forms set within the formwork to produce the perforated openings. Te polystyrene forms spanned the thickness of the wall

121

Why Cast?

FIGURE 2.66 TEA windows at exterior surface of concrete façade. Photo: Koppchen [CC BY 3.0 (http s://creativecom mons.org/licens es/by/3.0)].

FIGURE 2.67 TEA windows at interior surface of concrete façade. Photo: Hajotthu [CC BY 3.0 (http s://creativecom mons.org/licens es/by/3.0)].

and some apertures are six feet long. Once the concrete set, the polystyrene was destroyed during the formwork removal. Load-bearing cast concrete walls are typically solid constructions and the steel rebar embedded in the concrete is a complex framework. In conventional cast concrete constructions, bent rebars negotiate between horizontal and vertical concrete components (between foor slab and column). In TEA, the steel rebars bend around every window in order to construct the load-bearing concrete wall. Te apertures at TEA are complex and precise forms perforating the concrete walls. Te patterning of the apertures creates a texture in the fat monolithic walls. In

122

What Happens When Casting?

manipulating larger scale texture into a cast concrete building, Peter Haimerl’s Konzerthaus Blaibach articulates both the exterior and interior concrete surfaces using two diferent strategies. Te concrete exterior is fnished using specifcally selected granite stones. Te arrangement of granite on the exterior is very calculated. Each granite stone is placed so that the fat face of the stone is parallel with the concrete surface. Te surface texture is rough, but also it is consistent in its arrangement. At the building corners, the stones are stacked to defne a clear edge condition outlining the building form. Te vertical control joints in façade give scale to the sculptural form of the Konzerthaus Blaibach. Te pure rectangular volume of the concert hall tilts up emerging from the ground. Te concert hall entrance is brilliantly defned by the tilted end of box providing just enough clearance to access stairs embedded into the ground (Figure 2.68). Te tilting of the building volume not only creates the entrance vestibule, but also the angle of the tilt is coordinated with the raked seating inside the concert hall. Inside Konzerthaus Blaibach, the poured-in-place concrete is designed as a three-dimensional form that accommodates the acoustical needs of the space. Each pleat, fold, and fn on the surface has a purpose (Figure 2.69). Te formwork had to be so pre­ cise and exact that it was produced by experts in automotive fabrication. Te concrete at its thickest is 23.6 inches (60 cm) and at its thinnest is 2 inches (5 cm). Te hardness of concrete is desirable for playing classical music, but in addition, recycled glass aggregate provided roughness to the concrete surface. Te complexity of the cast concrete form not only addressed acoustics, but embedded within the concrete, there was a complex system of electrical wiring, radiant heating, and also a set of tubes for regulating bass sounds. Tis 200-seat concert venue is an astounding feat of precision. Te design and the construction process had to be extremely coordinated in order to execute the concrete casting.

FIGURE 2.68 Volume of perfor­ mance space tilts up to shape main entrance. Photo: Edward Beierle.

123

Why Cast?

FIGURE 2.69 Textured concrete walls inside the Konzerthaus Blaibach. Photo: Edward Beierle.

Te Konzerthaus Blaibach exterior façade addresses the public space, while the interior concrete accommodates the acoustic and infrastructural needs for a music space. Te interior concrete is designed with layers of texture. Te concrete surfaces are cast in horizontal bands that tilt and fold throughout the concert hall with recycled glass aggregate adding additional texture and detail. Te horizontal pleats create a large-scale texture with functional purposes. Each pleat is angled to refect sound and they also house the lighting fxtures (Figure 2.70). Te LED light grazes the concrete surface emphasizing the angles and further adding depth and shadow to the cast concrete. Along the same lines, the second cast concrete component in the Clyford Still Museum is a large span ceiling surface that is concrete slab cast with precision. Te ceiling of the Clyford Still Museum is a delicate concrete screen that flters natural light into the galler­ ies (Figure 2.71). Te concrete screen has 12-inch thick ribs spanning the diagonal between parallel edges of the building. A series of elliptical apertures are set in between the ribs and they are oriented to create complex curvatures that capture and difuse daylight, and address the specifc intensity of the light in central Colorado, the building’s orientation, and the glare from neighboring structures. Te formwork is CNC milled in polyurethane foam and steel reinforce­ ment is set within ribs of the formwork. Each aperture in the concrete has a three-dimensional shape with varying angles to capture light throughout the day producing an elegant and refned screen. Aside from difusing natural light, the concrete screen at Clyford Still Museum also appears light in weight as it delicately hovers across the gallery spaces. Te concrete ceiling is cast as one element and within the building it appears to defy gravity. Te curves within the concrete screen picks up light that the edges of each aperture dissolves into light. Te ceiling screen is integrated with the museum’s walls, held below the museum’s skylights, and spans the entire building. Te interior walls of the galleries are lowered to allow the con­ crete screen to extend over gallery spaces to further emphasize the concrete’s lightness. Te concrete slab transmits natural light into the building while also it challenges the appearance of concrete’s weight.

124

What Happens When Casting?

FIGURE 2.70 Detail of the faceted interior concrete surface. Photo: Edward Beierle.

Form and Lightness: How Thin Can We Cast a Material? Tis brings us to the next series of constructions that have pushed the structural limits of a cast concrete. In working with any building material, understanding the limits of that mate­ rial helps us to know how the material will behave and how else we can work with it. With cast concrete, characterized by its mass and weight, the breaking point comes down to the

125

Why Cast?

FIGURE 2.71 Concrete screen diffusing light into the Clyfford Still Museum. Photo: Lisa Huang.

dimensional thinness of the cast form. Structural innovations not only defed the massiveness of concrete but also tested geometric form as a means of creating lightness in cast concrete. For the 1939 Swiss Exposition in Zurich, Robert Maillart designed the Cement Hall to showcase the structural possibilities of cement. Maillart was a pioneering engineer in experimenting with the limits of reinforced concrete shell structures. Te objective of the Cement Hall was to create a thin structural concrete shell with a minimal amount of material (Figure 2.72). Maillart was able to cast a reinforced concrete vault less than 2.52-1/2 inches thick by using a parabolic catenary cross section. His intention was to use as little cement as possible to demonstrate that with concrete, the form of the structure can minimize the amount of material. Te Cement Hall was an engineering feat at that time not only because of its thinness, but also for the overall form of the structure. Cast concrete relies on mass for its load-bearing capabilities. Te Cement Hall demonstrated that form can replace mass in providing strength for a concrete structure. Te formwork for the vaulted shell was made of curved timber and the concrete was applied over

FIGURE 2.72 Robert Maillart’s Cement Hall. Photo: courtesy of ETH Zurich.

126

What Happens When Casting?

steel reinforcement 3.5 inches (8mm) by spraying the concrete over the shuttering. Te shell only needed to accommodate snow loads and no live loads, so this allowed the concrete to get thinner. Te vault was 70 feet long, 89 feet wide, and 50 feet high with a pedestrian bridge tying together the two sides of the vault. Te cement shell was elevated of the ground by four concrete columns on each side of the vault. Two stifening arches, aligned with columns, ran along the center of the barrel vault, supported the pedestrian bridge, and extended down to the ground. Te structure had two primary parts, the thin arch of the shell and an L-shaped cantilever that folded outwards to provide rigidity. Since the Cement Hall was to be demolished at the end of the Expo in 1940, Maillart used this as an opportunity to test the behavior and breaking point of thin concrete under stress.1 During the demolition, Maillart applied point loads and discovered that the shell could resist deformation and torsion. In addition, the Cement Hall’s shape had a very high load capacity. No amount of applied load caused the concrete to fail which proved that the vault’s geometric form was completely sound even as a thin shell structure. Te shell only started to fail when the pedestrian bridge was destroyed. Tis caused the stifening arches to buckle and the shell consequently fell. Concrete is universally understood as a thick dense material that relies on mass for structural stability. Maillart tested the ability to cast concrete in other geometric forms and questioned whether concrete was capable of more elegant forms that defy its conventional characteristics. Since the Cement Hall was an experiment, Maillart could intentionally test the thin concrete structure to the point of failure. In professional practice, we do not have the luxury of taking design risks that could impact life safety. Expo pavilions are often temporary testing grounds for material and assembly innovations. Te buildings of Felix Candela, infuenced by engineers Maillart and Heinz Isler, focused on testing thin concrete shell structures and further pushed the innovative use of concrete. Before building full-scale concrete structures, Candela started by recreating thin shell concrete experiments to analyze the forms and the construction processes.2 Tis experi­ mental stage in his work was critical in establishing a foundation for his thin concrete struc­ tures. Candela used this time to anticipate issues and to understand research and experiments that have already been conducted in order to then consider the next innovative possibilities. In 1951, Candela built his frst thin shell commission, the Cosmic Rays Laboratory on the Universidad Nacional Autonoma de Mexico (UNAM) campus in Mexico City. Tis 1,400 square foot structure would house two small laboratories. Te thin concrete shell is elevated approximately eight feet of the ground held by three concrete arches to further emphasize the lightness of the structure (Figure 2.73). Te shell is a hyperbolic paraboloid vault which is essentially a saddle shape that can be formed by ruled surfaces. Te geometry of the hyperbolic paraboloid could structurally support the thinness of concrete better than a conventional barrel vault. In the Cosmic Rays Laboratory, the formwork used straight boards crossing at a 60-degree angle to create the saddle shape. At the top of the saddle, the concrete has a thin­ ness of less than 2 inches (5 cm). Candela used a minimum amount of concrete to cover and insulate the steel reinforcing. Like in Maillart’s Cement Hall, Candela added concrete arches to stifen the structure at the high points of the shell. However, in the Cosmic Rays struc­ ture, the stifening arches are in the underside of the shell so that the shell maintains a pure expression of geometry on the exterior. After the Cosmic Rays Laboratory was built, Candela

127

Why Cast?

FIGURE 2.73 Cosmic Rays Laboratory by Felix Candela. Photo: Unknown [Public domain].

realized that the three stifening arches were perhaps unnecessary for strengthening the shell.3 Tey were added to make sure that the structure would not fail. As this was his frst thin shell commission, Candela was still pushing the limits of casting concrete, but he also had to be more conservative since this structure was to function as laboratory space. Te success of the Cosmic Rays construction inspired Candela to take bigger risks in subsequent projects to push the potential thinness of concrete. Candela was interested in the ability to cast a plastic material of concrete into any complex geometric form and the structural potential of an economical material that could exceed aesthetic expectation. Even though concrete is an economical material, Candela continued to test the minimal amount of material needed to create a structurally sound form. Te geometry of the shell shape was one factor in determining the structural strength. He was casting forms that defed expectations and showcased the structural potentials of the material. Te saddle shape of Candela’s Chapel Lomas de Cuernavaca had a more dra­ matic form compared to Cosmic Rays Laboratory. For the chapel, Candela, knowing that his forms were untested, factored in additional costs in the construction in anticipation of potential failure.4 One end of the chapel has a steep end that arches 78.7 feet (24 m) above ground. Candela avoided using an edge beam or arch in this structure in order to preserve the thin appearance of the saddle. Te formwork for the concrete cast consisted of straight wood boards set along a ruled surface of the structural shape. Te formwork was erected with heavy steel reinforcing to shape the underside of the shell. A double formwork was not needed because the concrete was a dry mix applied by hand. Each step in the process of construction afected the success of the structure. Te scafolding for the formwork was extreme in order to achieve the tall fared ends of the chapel. Te saddle form was pushed to its limits in height and its structural capabilities, so even the process of disassembling the formwork was a delicate situation for the structure. Te frst

128

What Happens When Casting?

version of the chapel collapsed when the shuttering was removed. Te concrete may not have set to the appropriate strength before removing formwork and it jeopardized the stability of the geometric form.5 In that frst construction, the formwork decentered the concrete so the weight and structural forces were not evenly distributed when the scafolding and formwork were removed. Since Candela had anticipated possible failure, in the subsequent construc­ tion, the height of the fared shell end was lowered seven feet. Te side of saddle was thickened to absorb additional structural load. Te concrete remained 1.5 inches (4 cm) thick through most of the shell structure. Candela’s complete body of work continued to test other complex geometries for thin shell concrete forms. In a more recent construction, we are still fascinated with the illusion of thinness and lightness in concrete. Unlike Candela’s structural strategy with thinness using geometry of form, Alvaro Siza’s Portugal Pavilion in Lisbon hangs a thin concrete canopy pre-stressed by steel cables. Te pavilion has two 45 feet (14 m) tall load-bearing porticos that support steel cables that stretches 213 feet by 190 feet (65 meters by 58 meters). Te concrete slab is cast with a uniform thickness of 7.87 inches (20 cm), but because of the large span, the con­ crete appears thin and light. From a distance, the draped form makes the concrete look like a delicate sheet of fabric (Figure 2.74).

FIGURE 2.74 Thin concrete draped at the Portugal Pavilion. Photo: Andy Bosselman from Denver, CO, USA [CC BY 2.0 (http s://creativecom mons.org/licens es/by/2.0)].

129

Why Cast?

Te two porticos are designed to resist the forces exerted by the concrete roof and in combination with the concrete canopy, the pavilion provides shade and frames the view toward the sea. Te vertical distance between the edges of the concrete to its low point is approximately ten feet (3 m). Wind is the biggest structural challenge to the hanging concrete structure. If the concrete is too thin and the wind uplifts the canopy, then it would cause structural failure in the concrete. Tere is a gap between the structural porticos and the con­ crete canopy that reveals the steel cables and allows wind to pass through (Figure 2.75). In addition, this gap further emphasizes the lightness in weight of the concrete. Concrete has pores that do not connect continuously through the material, so concrete generally keeps water out. As previously discussed, moisture becomes a concern when it freezes and thaws in the pores causing expansion and contraction in the concrete. Also, concrete operating alone as a building enclosure will thermally bridge between exterior and interior. Candela’s concrete work in Mexico only had to deal with warm weather, so

FIGURE 2.75 Detail of the joint between the concrete and the portico. Photo: Zachary Wignall.

130

What Happens When Casting?

additional layers of insulation and weatherproofng were unnecessary. Requirements for add­ ing layers of materials to protect and enclose concrete constructions certainly challenges the possibility of showcasing concrete’s thinness. In several buildings by Eero Saarinen, we can see an evolution of experiment­ ing with casting thin concrete while also constructing thermal assemblies. Several of his projects in the mid-20th century experimented with the technical and expressive potential of cast concrete shells as part of a building enclosure. Te geometric form of the concrete structures was more important than seeing exposed thin concrete. Saarinen used each project as a learning experience for his next building.6 Since thin shell concrete was a struc­ turally innovative construction at the time, working through problems was inevitable. But with each building, Saarinen would re-examine and rethink the assembly strategy for his next building project. Te frst cast reinforced concrete shell building we will discuss is the MIT Kresge Auditorium (1955). Te building roof was thin shelled dome, essentially one-eighth of a sphere, that was very economical in materials and cost (Figure 2.76). Tree equally spaced points of the concrete shell rested on abutments that were buried in ground. At the top of the dome, the site cast concrete shell was 3.5 inches thick. Te concrete thickened at the base to 18 inches. For waterproofng and thermal insulation, the top of concrete dome was covered with a thick coating of felt membrane, 2 inches of glass wool (an asphaltic fabric), 2 inches of cinder concrete, and an acrylic plastic mixed with fber beach sand for waterproofng and sound insulation (Figure 2.77). Saarinen did not include edge beams in the concrete shell, but then they found that without edge beams the shell form was struc­ turally unstable. Te mullions in the glass façade were then designed as structural members to help support the roof. In the Yale University David S. Ingalls Rink (1958), Saarinen proposed a rein­ forced concrete saddle-shaped roof using steel cables. Te roof was a parabolic arch creating

FIGURE 2.76 Kresge Auditorium at MIT by Eero Saarinen. Photo: Jack E. Boucher. [Public domain].

131

Why Cast?

FIGURE 2.77 Close-up of the abutment and the roof. Photo: Fred Gutierrez.

a central spine spanning the building length (Figure 2.78). Tis concrete structural arch was stabilized by a matrix of steel cables running parallel and perpendicular to the arch. Tis network of cables anchored to the exterior walls and draped in catenary curves creating a tensioned steel web (Figure 2.79). Tese exterior walls also tilted outward to increase struc­ tural efciency and resist forces in the cables. In this building, Saarinen responded to the lessons learned from Kresge auditorium regarding waterproofng. He used a neoprene sheath for water protection in the roof assembly. However, the roof was not insulated, so as a result, moisture would condense inside the rink creating fog.7 Te TWA Terminal (1962), one of Saarinen’s last buildings, continued with his use of cast reinforced concrete but in another more complex geometric form. Te TWA Terminal is the most fgurative of Saarinen’s works. Te concrete shells of the building extend outward as if it were about to take fight (Figure  2.80). Te edges of the con­ crete roof are 7-inch thick, but to support the cantilevered extension of the thin concrete, the concrete shell changes thickness to accommodate structural needs (Figure 2.81). Te

132

What Happens When Casting?

FIGURE 2.78 Ingalls Hockey Rink at Yale University by Eero Saarinen. Photo: Carol M. Highsmith [Public domain].

FIGURE 2.79 Concrete arch and cables of Ingalls Hockey Rink dur­ ing construction. Photo: Balthazar Korab [Public domain].

thickest point of the concrete shell is a 44-inch-deep horizontal concrete keystone. Te formwork for the concrete shell uses both straight wooden boards and treated and bent wooden boards. Since the board forms were specially ft for the cast concrete shell, they could not be reused. In this building project, the formwork accounted for 50% of roof construction cost. In the TWA terminal, the roof remains as exposed concrete unlike the Kresge Auditorium and the Hockey Rink.

133

Why Cast?

FIGURE 2.80 TWA terminal aerial view. Photo: Rich Lemonie [CC BY-SA 4.0 (https:// creativecommons. org/licenses/by -sa/4.0)].

FIGURE 2.81 Cast concrete during construction of TWA terminal. Photo: Balthazar Korab [Public domain].

Plasticity and Mass: How Else Can We Highlight the Fluidity of a Cast Material? In Candela’s work, his curved geometric forms worked well with cast concrete that was thicker in viscosity. Te plastic state of a cast material like concrete is temporary. When the material hardens, its initial fuidity is not necessarily present in its cured state. Te thinness and elegance of Candela’s curved concrete forms captured a fuid movement inherent in the casting. Tese qualities defy the massiveness of cast concrete by minimizing material and maximizing form to maintain structural integrity. In essence, there is a visual and a physical

134

What Happens When Casting?

reduction of material, but it is in the form of the cast that we can capture the characteristics of appearing more liquid than solid. Focusing on diferent scales, we will now look at additional ways of emphasizing the liquid state of concrete. Tis difers from thinness in Candela’s work. Instead of pushing to the physical breaking point, these buildings cast concrete emphasizing fuidity. At the scale of the building, a cast concrete structure does not necessarily have to be thin to capture fuidity. Sergio Musmeci’s Ponte del Basento is a reinforced cast concrete bridge with a consistent thickness of 11.8 inches (30 cms). Te form of the bridge is a single concrete slab that pulls up and down at points to form four arches that support a roadway (Figure 2.82). Te cast concrete touches the ground and the roadway lightly with its tapered points. Te concrete twists as it transitions in form extending from the ground to the road consequently emphasizing a fuidity in the cast concrete. Te structure for the bridge is a sin­ gle monolithic concrete cast whose fowing shape contrasts the straight roadway it supports. Te lightness and fuidity of the concrete structure is reinforced by methods determining the form of the bridge. Musmeci’s study models used cotton threads and a flm of soap and glycerin to test structural shapes. Tese whisper-light materials helped determine the bridge’s geometry, but also their lightness has a proportional relationship with the cast concrete. Te viscosity of the concrete reinforces the plasticity of the bridge’s shape. Te shape of the mass and the proportions between the building size and the concrete thickness allows concrete to appear wavy and light despite its mass. SANAA’s Rolex Learning Center is a large mat building with horizontal concrete slabs for the foor and the roof planes. Parts of the slabs lift up and down to create passage underneath and into the building. Te cast concrete slabs are continuous planes perforated with large circular

FIGURE 2.82 Basento Bridge by Sergio Musmeci. Photo: Luigi Catalani [CC BY-SA 4.0 (https://c reativecommons. org/licenses/by -sa/4.0)].

135

Why Cast?

FIGURE 2.83 Construction of the Rolex Learning Center. Photo: User: Epfl Alain Herzog [Public domain].

openings that provide access points and bring light into the building (Figure  2.83). Te openings in the concrete slab emphasize the elegance of the curves and accent the fuidity of the structure. Te thickness of the concrete slab varies based on the structural needs in relation to the span of the concrete foating about the ground. Te concrete slab gradually lifts of the ground producing deep shadows that help reinforce the lightness of the structure. Underneath the building, the mass of the concrete slab appears to foat as it spans across the ground (Figure 2.84).

FIGURE 2.84 The public space under and through the building. Photo: Lisa Huang.

136

What Happens When Casting?

At the smaller scale of the component, fuidity also is expressed through the formwork of the concrete cast. Te work of Miguel Fisac approached plasticity and light­ ness of cast concrete components with two strategies that challenge the heaviness and massiveness of concrete. In his early work, Fisac defed the mass of concrete by precasting concrete components that were then post-stressed into concrete beams. As demonstrated in the Hydrographic Studies building in Madrid, these precast modules completely defed the weight and mass of concrete because each concrete module was held in tension and together, the concrete modules basically foat in the air as the post-stressed beam spanned between load-bearing walls. Fisac was preoccupied with methods in achieving the “real expressions of con­ crete,” so he put a lot of thought into the shape of precast forms. He saw cast concrete as a material and operation capable of adapting to any shape needed for the building assembly. In the Hydrographic Studies building, Fisac wanted to bring light into the space, so the concrete components are shaped to refect natural light. To span the long distance as modules, he conceived of the concrete modules as hollow components like vertebrae. As a result, the shape of building components was both functional and expressive. Each precast concrete module became structural when it was compressed into a beam. Also, the curved shape of each mod­ ule helped to transmit light into the building. Later in his career, Fisac shifted his focus toward pushing the expressions of con­ crete even further. He experimented with other techniques of addressing concrete’s plasticity and mass specifcally using fabric as formwork for casting concrete into component panels. Up until then, curved cast concrete forms typically used wood for formwork. But this meant that the texture of the wood would be imprinted on the concrete surface. In the La Pagoda building (1970), wood formwork was used to produce precast panels that emphasized con­ crete’s playful possibilities. Fisac used a single formwork design and then alternated the ori­ entation of each module to create the building’s shape. Te wood paneling of the formwork was visible on the concrete surface. Trough these projects, in Fisac’s later work, he became interested in expressing concrete’s liquid form and rethought the casting process developing fabric-formed concrete to expose the fuidity of the concrete. Fisac made formwork out of wire and thin sheets of fexible polythene that allowed the concrete to deform in the mold to retain its liquid appearance. Te fabric formwork allowed the concrete to settle in balance with the fabric’s fexibility creating subtle varia­ tion in each fabric-formed panel. As a result, the concrete cast captured the viscous state of the concrete. For many building projects, the fabric-formed concrete was cast in panels. At Clinica Mupag, the precast concrete panels also turned corners to emphasize the plasticity of concrete not only at the material scale but also at the building scale. Fisac’s own house and studio in Cerro del Aire became a testing ground for larger assembly methods. Fisac created fexible formworks that precast concrete on site. Te formwork had an internal structure imposing a grid to help control the viscous concrete. Tis let the concrete sag and deform in sections instead of in the entire panel. Fisac’s work with fabric-formed concrete has been inspiration for many cur­ rent experimentations with casting concrete. Led by Mark West, the work of Centre for Architectural Structures & Technology (C.A.S.T.) at the University of Manitoba takes Fisac’s studies further by carrying on fabricform experiments and reimagining typical concrete com­ ponents in buildings – precast panels, foor slabs, columns, and beams. For example, with

137

Why Cast?

the concrete beam, C.A.S.T. has used fabric formwork to cast beams that minimize material, reduce formwork construction time, and refect exactly where structural forces occur. Teir designs are more efcient in amount of material used to maximize the concrete beam’s struc­ tural efectiveness. In comparison to wood or metal shuttering, the fabric formwork is also less bulky, lighter, reusable, and it is easy to assemble and dissemble. C.A.S.T. also consulted on the casting methods for Byoung-Soo Cho’s Hanil Visitors Center and Guest House. Te project was built for the Hanil Cement company in Korea who wanted to showcase the potentials for their product. Te primary façade of the building uses fabric-formed concrete to showcase the fuidity of the concrete. Each panel spans the full height of the building and they are precast on site as long elements and then tilted vertically for assembly. Te concrete was cast in a wood formwork structure using tubes that supported the plastic fabric liner. Tis consequently limited the extent of con­ crete bulging. In the fabric-formed concrete panels, the plasticity of the material is refected in the curvature of the panels but also in the interaction between the fabric and the wood formwork. Te appearance of plasticity in cast concrete relied on a formwork that allowed the concrete to express its original material state. When the fuidity and the viscosity of concrete is emphasized, it creates the illusion of lightness in its weight and mass because its appearance redirects our attention to the liquid state of concrete. But regardless, casting concrete requires mate­ rial thickness in order to be a substantial building component. Concrete can be thin with certain structural geometric forms, but it is not a typical thin sheet material that minimizes the material or emphasizes other aspects of thinness. Tere is always a material volume and mass associated with casting concrete. It is inevitably a heavy material. Cast concrete is also not limited to refecting characteristics that are in sync with the construction methods. Le Corbusier’s Notre Dame du Haut in Ronchamp appears as a heavy, thick, and massive cast concrete structure, but in actuality, the whole building uses concrete casting methods in three diferent ways that minimized the amount of concrete material needed (Figure 2.85). Te walls and the roof appear as thick concrete structures, but they are, instead, very thin and composed to look monolithic and heavy. Te roof was constructed of two thin cast-in place concrete shells cast together as a hollow free-form clamshell that was supported on cast concrete columns. Te east and north walls are masonry assemblies reusing stone rubble from previously demolished churches in the area. Te southern stained-glass wall was a cast concrete open frame that provided the internal structure for the four-foot thick wall. Sheets of metal lathe attached to the concrete frame and shaped the deep windows of stained glass. Te concrete frame and metal lathe cre­ ated an armature for the window wall (Figure 2.86). A thin layer of gunite was then sprayed onto on the masonry walls and the metal lathe to create a unifed concrete surface that hid the numerous assembly methods employed in the building construction.

138

FIGURE 2.85 Exterior view of the stained glass window wall. Photo: Zachary Wignall; © F.L.C. / Adagp, Paris, 2019 sauf pour l’église de Firminy: © F.L.C. / ADAGP, Paris [année/year] et José Oubrerie [Conception, Le Corbusier architecte, José Oubrerie assistant (1960–1965). Réalisation, José Oubrerie architecte (1970–2006)] et pour la Chapelle Notre Dame du Haut à Ronchamp: © ADAGP, Paris [année/year].

What Happens When Casting?

FIGURE 2.86 Masonry construc­ tion before the application of sprayed concrete © F.L.C. / Adagp, Paris, 2019 sauf pour l’église de Firminy: © F.L.C. / ADAGP, Paris [année/year] et José Oubrerie [Conception, Le Corbusier architecte, José Oubrerie assistant (1960–1965). Réalisation, José Oubrerie architecte (1970–2006)] et pour la Chapelle Notre Dame du Haut à Ronchamp: © ADAGP, Paris [année/year].

Le Corbusier used concrete because it was more economical than stone masonry. And the continuous mate­ rial helped to present the chapel as a monolithic structure. Te process of casting concrete is not necessarily limited to creating the appearance of massiveness as we saw in the buildings that pushed geometric and structural possibilities. In Notre Dame du Haut, curvature and thinness in the building was constructed through a conservation of materials. What makes Notre Dame du Haut interesting to us is that the building created the illu­ sion of a monolithic mass formed in concrete, but instead, the building was composed of an assembly of parts. Te thickness of the chapel’s south wall deceivingly looks as if it is a thick cast of concrete (Figure 2.87). But a building does not have to be a cast for it to look monolithic and heavy. In construction, there are always multiple strategies to achieve a desired appearance. We should not think of concrete as just a cast material. It can play a more complex role in the buildings we construct.

FIGURE 2.87 Construction of the stained glass and concrete wall © F.L.C. / Adagp, Paris, 2019 sauf pour l’église de Firminy:© F.L.C. / ADAGP, Paris [année/year] et José Oubrerie [Conception, Le Corbusier architecte, José Oubrerie assistant (1960–1965). Réalisation, José Oubrerie architecte (1970–2006)] et pour la Chapelle Notre Dame du Haut à Ronchamp: © ADAGP, Paris [année/year].

139

Why Cast?

Notes 1 2 3 4 5 6 7

140

David P. Billington, Robert Maillart and the Art of Reinforced Concrete, (New York, Cambridge: Architectural History Foundation, MIT Press, 1990), 104. Maria E. Moreyra Garlock and David P. Billington, Felix Candela: Engineer, Builder, Structural Artist, (New Haven: Princeton University Art Museum, Yale University Press, 2008), 65. Ibid., 88.

Ibid., 138.

Ibid., 134–138.

Reinhold Martin, “What Is Material?” in Eero Saarinen: Shaping the Future, ed. Eeva-Liisa

Pelkonen and Donald Albrecht, (New Haven: Yale University Press, 2006), 75. Jayne Merkel, Eero Saarinen, (New York: Phaidon, 2005), 130.

Chapter 3

Why Carve?

3.1

What Can We Carve?

In the operations examined so far, we have looked at building construction methods that require the use of additional supporting building material to help shape the assembly. Stretching requires forming and shaping with a frame. Casting requires forming and shaping with a removable formwork. In the operation of carving, the building material is formed and shaped by removing or subtracting parts of a dimensionally stable material. Te operation of carving, or more familiarly milling, requires the use of tools, machines, and other processes that help to cut into a material. A carved material can take on any complex geometric form. Milling is a carving strategy that implies the use of machines and equipment. In this chapter, we will use the broader term of carving so as to include the use of hand tools in the removal of material.

Typical Carving Materials and Components Scale of the Building Cave dwellings and carving into the earth were known primitive approaches to making spaces for human occupation. Te construction process requires tools and labor for excavat­ ing and moving earth. Te natural topography, typically stone, is shaped and cut away to create occupiable spaces. With just the use of simple tools, carving into the natural ground can accommodate our most basic need for shelter. In the most elemental process of produc­ ing occupiable space, carving is an operation that only uses one material and an assembly of components is not required. At the Rock Sites of Cappadocia, these natural landforms, over one hundred feet in height and eroded by wind and water, were carved by hand to become protective spaces camoufaged in the landscape (Figure  3.1). Te earth in Cappadocia consists of soft rock from volcanic ash. Carving into the soft rock topography was a defensive strategy. Occupants needed their dwellings to be completely disguised and invisible. Tey also carved tunnels connecting between spaces in order to avoid being seen and exposed. At Cappadocia, the carved spaces are intentionally hidden within earth, so they did not carve ornate facades. Te

143

Why Carve?

FIGURE 3.1 Cappadocia. Photo: Bernard Gagnon [CC BY-SA 3.0 (https://c reativecommons. org/licenses/by -sa/3.0)].

exposed surfaces of the earth and topography were minimally changed and only altered for access. In this case, the existing earth was cut and removed as a strategy to address the large scale of the building and the occupant. In another UNESCO World Heritage site, the buildings in Petra, Jordan were cut into the sandstone desert clifs and ornate stone facades were added thresholds into the carved spaces. Unlike the Rock Sites at Cappadocia, the architecture at Petra was both carved and additive. Te carved structures were primarily institutional or religious, so they were not built for hiding or defensive purposes. Te advantage of carving the land protected the important buildings from the harsh efects of wind and water. Spaces were hand-carved into the sandstone earth, but then elaborate facades were stacked stone assemblies integrated into the face of the sandstone clifs (Figure 3.2). Te operations of carving earth occurred at both the scale of the building space and at the scale of the building component. Each stone block of the façade was carved to celebrate the importance of the building function. Te stepwells in India are another example of architecture carved into the earth. Instead of cutting into vertical landforms like in Petra and Cappadocia, stepwell structures are carved into horizontal ground. Te occupiable spaces of stepwells were typically carved several stories down into the earth (Figure 3.3). Te functions of stepwells were to capture water and to take advantage of the cooler temperatures deep in the earth providing refuge from the hot tem­ peratures above ground. Te architecture of the stepwell used the operation of carving at both the scale of the building space and the scale of intricate ornamentation in building components. Due to the large scale of the carved building space, the procession down into the stepwell was intended as a monolithic and grand experience. Te stepwells were community spaces where everyone could access water and cool down. Not only was earth cooler further into the earth, but also the carved earth cast a shadow shielding the harsh rays of the sun. Te stepwells were an interesting inversion of buildings as we know it. Instead of the stepwell building being an object above the ground, it is a negative or void space. Te stepwell extends straight down into the ground. Te enclosures that defne the functional spaces are not an

144

What Can We Carve?

FIGURE 3.2 The Treasury building at Petra. Photo: Petra,_ The_Treasury. jpg: John Thomas from Sydney, Australiaderivative work: MrPanyGoff [CC BY 2.0 (http s://creativecom mons.org/licens es/by/2.0)].

assembly of parts, but instead, the enclosures are a resultant condition in removing earth. To celebrate the stepwell’s institutional and public function, the walls were stacked stone handcarved with elaborate designs (Figure 3.4). Te addition of the carved stone blocks superim­ posed a component scale to the monolithic scale of carved earth and it helped to relate the vast space of the stepwell to the human scale. Of course, we know that harder stones are quarried with the use of substantial equipment and labor. Most commonly, the earth that is carved for human occupation occurs in soft stone. In most historical cases of carving earth, manual labor and the lack of mechanical equipment restricted locations that could be carved into occupiable spaces. Starting from the 1st century and through the mid-20th century, Matera, Italy has a long history of cave dwell­ ings called Sassi carved into the deep gorge (Figure 3.5). Te side of the gorge became where the poor created rupestrian churches and dwellings for themselves (Figure 3.6). Te tufo stone in Matera is soft and easy to excavate by hand. As a result, the Sassi are an intricate network of underground spaces that relied on the integrity and stability of the tufo stone. Networks of

145

Why Carve?

FIGURE 3.3 View into the Adalaj stepwell. Photo: Karthik Easvur [CC BY-SA 4.0 (https://c reativecommons. org/licenses/by -sa/4.0)].

FIGURE 3.4 Carved stone deco­ rating the Adalaj stepwell. Photo: Lisa Huang.

146

What Can We Carve?

FIGURE 3.5 Panorama view of Matera’s sassi carved into the gorge. Photo: Lisa Huang.

FIGURE 3.6 Sassi dwelling entrance. Photo: Lisa Huang.

147

Why Carve?

spaces were carved horizontally into the slope of the mountain gorge and they staggered with the slope of the mountain to create accesses and terraces. Te carved dwellings stacked on top of each other, so the carved volume tended to be vaulted spaces. Te shape of the vault not only provided structural bracing, but it also reduced the amount of stone to be removed. For access to water in the Sassi, they carved vertically to make wells from inside the staggered dwellings. Tese tall spaces were narrow at the top of the access point and widened at the bottom of the well. Once a well dried out, they carved horizontally to con­ nect the empty well with adjacent cave dwellings to increase occupiable spaces. In Matera, Casa Cava is an old well transformed into a modern-day multifunctional performance space (Figure  3.7). Te soft tufo stone is also an ideal environment for playing the violin. Te spaces in Casa Cava preserves the network of carved spaces and reveals a systematic process of removing the stone (Figure 3.8). Te traces of carving are present in the patterned texture on the stone’s surface. To connect between adjacent spaces, columns were carved out of the stone to support a larger span of space. Tere was no need for additional structural members spanning the space. Instead, they carved in limited distances and strategic volumes that were completely reliant on the integrity of the stone. Te operation of carving earth to form occupiable spaces is not exclusively a his­ torical or primitive strategy. Built in 2009, Villa Vals, adjacent to Peter Zumthor’s Terme Vals, is a dwelling carved into the earth and buried in the Swiss Alps mountainside. Te architectural collaboration of SeARCH and CMA emphasized the concept of occupying the earth with the entry sequence into the house. Access to the underground dwelling of Villa Vals starts at an existing barn and then under the earth through a tunneled corridor. Along the slope of the mountain, the oval drum volume intersects with the earth and the removal of earth at this intersection creates a nested outdoor terrace (Figure 3.9). Tis carved volume also allows for windows to bring light into the house. A stone façade wrapping the surface of the carved volume is reminiscent of a quarried site – as if the removed earth reveals the layers of stone.

FIGURE 3.7 Section drawing of Casa Cava.Photo: Lisa Huang.

148

What Can We Carve?

FIGURE 3.8 Interior space of Casa Cava. Photo: Lisa Huang.

FIGURE 3.9 Façade of Villa Vals. Photo: Lisa Huang.

149

Why Carve?

If we look at the interior of Villa Vals, we also see that the building’s section emphasizes the carved nature of the villa’s functional spaces. On the interior, site cast con­ crete retains the earth and bounds the occupiable spaces. Each of the bedrooms is nested into one another in the same manner as the villa nesting into the earth. Tese shifts in the building section create platforms for beds, but consequently it shapes the spaces below. Te shifts of spaces carved into the villa interior transmits shifting windows and rooms onto its stone façade. From the terrace looking out to the landscape, an oblique circle inscribed into the ground frames the view within the mountain and valley. Te carved nature of the terrace is reinforced with a ledge separating the ground from the occupiable spaces of the villa. Above the ground surface, there is a fence added to defend against falling objects, snow retention, and any issues of ground erosion.

Scale of the Component In examining a smaller scale of carving instead of focusing on specifc materials, we will discuss carved components in terms of sheets or chunks of material. Panels of wood, stone, foam, metals, thermoplastics, and acrylics can all be cut away to produce apertures or screens. Tere are a countless number of architectural projects that have milled metal or wood sheet materials for fnish surfaces. In addition, etching or making shallow carvings onto material components produces intricate surface details like the stone carvings we just discussed in the stepwells. At the Chapel of St. Ignatius, Steven Holl used Alaskan yellow cedar for the cus­ tom doors of diferent sizes – one for private entry and the other scaled for larger ceremonies (Figure 3.10). Both thick doors are a composition of cedar planks accented with bronze at the base and the door handles. A total of seven oval windows, referencing the spatial concept of the chapel, are hand-carved into the thick cedar doors. Each window varies in oval shapes and angles to reinforce Holl’s concept of the seven diferent lights in the chapel. Te apertures carve into the wood doors to reveal the mass and solidity of the cedar. Te inner edges of the apertures are sanded smooth to further help refect light into the chapel. Te process of carving is visible as a texture on the exterior and the interior sur­ faces of the wood doors. On the exterior, the doors are monolithic and the wood planks are aligned vertically. On the interior, there is composition of texture and light from the matrix of wood planks and the carving traces (Figure 3.11). Te wood planks change directions and rectangular wood sheets are screwed into the doors to support the glass panes in the aper­ tures. Te carved texture on the wood surface is systematic but clearly irregular so it does not look machine milled. Tis texture picks up light that slips in when the entrance doors open and the hand-crafted marks encourage tactility and intimacy between the chapel doors and the occupant. At Villa Solaire, Jérémie Kœmpgen Architecture converted an old farm building and milled spruce wood planks to create a façade that also adds another scale of texture and light to the building. Te villa complex used typical board and batten wood facades to unify the buildings, but three-dimensional shapes are milled into each wood board to transform the wood paneling into a screen assembly (Figure  3.12). Te wood cladding is a weather

150

What Can We Carve?

FIGURE 3.10 St Ignatius exterior of wood doors. Photo: Zachary Wignall.

barrier and transmits natural light and ventilation into the building. Local carpenters con­ structed the wood façade and as a whole assembly, the milled boards create a pattern that wraps around the villa and coordinates with functional needs of each occupiable space. Te narrow wood battens, at a width of 2.36 inches (6 cm), are not milled. Te battens establish a constant rhythm in the façade. Te wider wood boards, at a width of 10.6 inches (27 cm), are milled creating additional shadows in the façade. Te shadows from the batten cast onto the boards and then contrasts of light and shadow from the milled boards create additional spatial depth in the building façade (Figure 3.13). Te wood boards are carved where natural light is needed within the villa. Te wood boards are milled with straight cuts, but the façade relies on layers of wood for a texture of light and shadow in the villa’s cladding. In both Villa Solaire and the Chapel at St. Ignatius, the components are carved or milled through to produce apertures. In contrast, etching carves a shallow depth into the surface of material components. A minimal amount of material is cut away to produce texture or patterns on the surface. Numerous materials like metal, glass, and concrete can be etched, but it may require additional operations. As we discussed in Chapter 2, the patterned

151

Why Carve?

FIGURE 3.11 Carving patterns at interior of wood doors. Photo: Zachary Wignall.

concrete at the Eberswalde Library is power washed away while the Yale Architecture and Art building by Paul Rudolph is bush hammered. Te Schaulager uses a combination of power washing and bush hammering to remove the surface layer of concrete.

Key Issues to Consider in Material Selection Whether the building material is hard or soft, we can cut into it with the appropriate tools and methods. Te primary concern we have in opting to carve a material is the dimensional stability of that material. Te material needs to have enough dimensional integrity to remain rigid and structurally sound, especially if the thickness of the material varies. If material is cut away, it is important for us to know how will the material react during the carving process and how will the material behave in its carved form. Some materials become more vulnerable to warping and failures with any changes or variations in its dimensional thickness. Carving into the earth depends on the consistency of the ground material. Additional materials like concrete retaining walls are then needed to hold back and stabilize

152

What Can We Carve?

FIGURE 3.12 Villa Solaire wood enclosure. Photo: Julien Lanoo, courtesy of Jeremie Kompgen Architecture.

FIGURE 3.13 Close-up of the milled wood clad­ ding. Photo: Julien Lanoo, courtesy of Jeremie Kompgen Architecture.

the earth. As we know, wood has a grain, so the direction and the depth of the carving could cause the wood to warp or crack. Another aspect to consider is regulating between the carv­ ing equipment and the material. Milling equipment will generate heat in the process of carv­ ing the materials. Terefore, we need to know if the material will stand up to the heat or if we need to tweak the process to accommodate the material.

153

How Do We Carve?

Typical Assembly Requirements Te operation of carving components includes material removal by hand with chisels, by hand-operated woodworking tools, by automated computer numerical control (CNC) mill­ ing machines, or through a combination of these strategies. Traditional methods of carving relied on hand-held tools to extract material. In carving earth, we need the help of large-scale construction equipment. When we think of ‘carving,’ there is an implication that the sub­ traction of material creates a three-dimensional result like all the marble sculptures we have seen throughout history. Carving subtracts and cuts away material, but it also implies that it produces shape with the depth of a material. In this chapter, we want to make a distinction between the two-dimensional removal of material and the three-dimensional shaping of material as ‘carving.’ At the de Young Museum, we discussed in Chapter 1, Herzog & de Meuron cuts away material in the copper cladding panels. Te fat sheets of copper were machine-punched to remove material which produces a lot of leftover copper. In perforating sheet metal, it does not create threedimensional space in the material. We will focus on discussing case studies that have cut into material in multiple axes. To carve with precision and refnement, it is a repetitive and gradual process of mate­ rial removal. Whether we carve by hand or with machinery, it requires multiple stages of carv­ ing, starting with rough cuts and then toward more precise and detailed cuts. Carving is an incremental and methodical sequence of removal. It is not possible to carve with refnement in one pass at removing material. Te number of passes at carving determines the fnish of the material. Ultimately, the material is sanded if the traces of carving need to be invisible. Te level of fnish depends on the desired efect and typically we hand polish to achieve really fne fnishes. Unless we carve by hand, the size limitations for carving materials is determined by the capacity of the milling equipment. Te technology of CNC mills continually advances in capacity and precision. Because the carving operation is occurring in three-dimensions, jigs may be needed to hold materials in position during the milling process. In the act of carv­ ing, there is resistance and tension between the tools and the material. Te tools are imposing their will on the material, changing the material’s form through force. 154

3.2

3.3

What Happens When Carving?

What Are the Failures/Limitations/ Problems We May Encounter? Te process of carving requires visualizing a preconceived form that then emerges from a material. Carving is a subtraction of material so that what remains is the fnal form. With the prevalence and advancement of digital fabrication tools, automated milling processes are the primary operations in carving building materials. One critical issue that we must acknowledge in the operation of carving is material waste. Since the carving process is usually a sequence of subtractions to create forms and spaces, the material that gets carved away is typically unusable. Since we carve in stages to refne form, the extracted material in carving becomes particles. Also, once material is removed, it is impos­ sible to fx or correct mistakes. Te subtracted material cannot be put back to its original or pre­ vious state. Major errors would require redoing the work which then uses even more material.

STUDENT EXPERIMENT

What Issues Emerge When We Let the Carving Process

Dictate Form and Appearance of Components?

Heather Holle | University of Florida Heather was interested in experimenting with carving a paneled material on both sides to examine the resulting intersections. Using wood boards and the CNC mill, she cre­ ated two three-dimensional forms that were independent of one another and then she applied each fle on opposite sides of the wood boards. Te overlap between the two three-dimensional cut fles resulted in perforations in the board. Creating apertures: Heather created several three-dimensional form patterns to carve into the boards that were composed of hills and valleys that followed and lengthened along the grain of the wood (Figure 3.14). Because Heather used 3/4-inch thick wood boards,

155

Why Carve?

FIGURE 3.14

Drawing fles of wood topographies. Photo: Heather Holle.

the curvatures were shallow and varied across the surfaces. In that shallow depth, the occurrence of overlaps between the two sides was difcult to predetermine. Te occur­ rence and the shape of apertures in the wood panel depended on the combination of curved forms used on either side of the board. Since the wood boards were thin, the material that was cut away becomes sawdust. Heather allowed the milling operation to produce the overlap that connected between both sides of the wood board. Addressing texture in the milled surface: Te variations in Heather’s three-dimen­ sional patterns led to inconsistencies in the grain cuts. Te boards were milled on two stages – frst, a rough cut like a series of topographic layers, then using a smaller mill bit, a fner cut that transitioned layers into curvature. Te two passes at carving were rough but it produced interesting patterns of texture and shadows in the board. Te wood fbers were cut in diferent axes, so it created a furry surface and the wood was not sanded to remove roughness (Figure 3.15). Te wood board in cross section had a large range of thickness despite the thickness of the board. At the apertures, the wood is extremely thin and fragile. Over time, the variation of thickness could lead to issues of cracking, warping, and breaking in the wood. Stabilizing the material during the milling and in the assembly: In carving both faces of the wood board, Heather took a risk in challenging the structural integrity of the wood during and after the milling operation. Te primary issue she addressed was whether there was enough material thickness to keep the wood rigid and structurally sound. Te two surfaces of wood could not be carved at the same time. One side is milled frst and then fipped onto the other side. Te carved surface was not fat or level, so the wood board was screwed to a jig to keep the wood board stable while milling the second side (Figure 3.16). Heather wanted to make sure that the uneven thickness of wood would not destabilize or catch onto the CNC mill bit.

156

What Happens When Carving?

FIGURE 3.15

Jig used while milling the wood board. Photo: Heather Holle.

FIGURE 3.16

Milled wood surfaces before sanding. Photo: Heather Holle.

157

Why Carve?

Operation and Composition: How Do We Make Something Predictable Look Unpredictable? Often, carved materials in building projects create organic forms that reference the appear­ ance of erosion in nature. Te forces of wind or water gradually remove earth to shape our natural landscapes, so its association with carving and milling materials is an obvious parallel in building construction. We selectively remove material to make organic shapes, but we rely on machinery to make building material look more natural. Erosion in nature implies an unpredictability of form. To carve, we need the tools to recreate and capture that unpredictability. In order to produce a carved form, we depend on developing technologies and tra­ ditional techniques but we cannot assume the digital fabrication tools will do exactly what we want. As with all equipment, we have to work with limits in milling machines to challenge con­ ventions. Te following projects use innovative approaches to adapt to digital fabrication tools and their parameters to achieve the desired efect. Tese projects carve components efciently to produce overall spatial efects and the composition of organic forms. Te large-scale appearance of these buildings is achieved through a unifed aggregation of individually carved components. At a quick glance, the Private House by Gramazio Kohler appears as a series of thin vertical wood slats that create a screen façade enveloping the house. Tree hundred and ffteen wood slats are fastened to a concrete load-bearing structure. Te repetition of the wood fns provides a more delicate and softer surface for the house in contrast to its concrete core. Te slats are perpendicular to the exterior wall so that it provides some depth for shade and privacy. Upon closer inspection, each delicate wood component is milled in cross section and as a uniform screen, achieving subtle changes of material thickness across the façade. Te cross section of each slat is shaped at angles while the length of the slat is also carved with gradual curves. Te space between the slats dictates where the wood is milled away to accom­ modate views and light. Te wood is carved in response to window heights to let in more light and to minimize view interference from the wood. Te wood slats narrow at the top of the façade aligning with the ribbon window set between the wall and roof. Te carving of the wood slat is three-dimensional and responsive to the sun orientation to also provide subtle shading. Te typical wood slat used for the screen maintains its overall dimensions while it also minimizes its dimensions at a smaller scale. Te repetition of wood components creates the appearance of a unifed surface. Seven thousand limestone blocks clad two building masses of Renzo Piano’s Valetta Parliament House. In its context of Malta, the thick stone façade panels are reminis­ cent of eroded stone. Te heaviness of the stone building masses contrasts with thin struc­ tural columns. Te stone masses foat above the ground generating an open public space that extends through the building (Figure 3.17). Te stone façade on the building masses are both monolithic and porous. Each stone panel is carved with ornamental detail, and as an aggregation of panels, it creates a pattern and texture that unifes the façade as a single mono­ lith (Figure 3.18). Te limestone is carved not just as decorative cladding. Each stone façade panel is CNC milled with the intention of fltering and refecting natural light. Te geomet­ ric forms carved into the stone also functions not just for light control but also for climate control. Te carving of the stone regulates solar heat gain and ventilation into the building.

158

What Happens When Carving?

FIGURE 3.17 Malta Valetta Parliament House by Renzo Piano Building Workshop. Photo: Continentaleurope at English Wikipedia [CC BY-SA 4.0 (https:// creativecommons. org/licenses/by -sa/4.0)].

FIGURE 3.18 Close-up of milled stone panels. Photo: VillageHero from Ulm, Germany [CC BY-SA 2.0 (https:// creativecommons. org/licenses/by -sa/2.0)].

Te cladding appears as stacked stone; however, a hefty steel structure fastened to reinforced concrete cores supports the stone panels (Figure 3.19). Te uncarved stone estab­ lishes a fat façade surface that aligns with the face of the carved stone. But the uncarved stones are thinner panels to efciently use the limestone. Te supporting steel structure adjusts to accommodate the carved and uncarved stone. Te depth of the carved stone gener­ ates added weight since they cantilever of the steel framework. Local limestone was used for the Valetta Parliament House, but during construction, issues arose with natural cracks and inconsistencies in the stone that afected its structural integrity. Subtracting materials from the stone also becomes a strategy eliminating the fawed parts of the stone. Te angles cut into the limestone refect sunlight but also the shadows generated by the stone’s carved form increase the depth and three-dimensionality of the façade. At Trerrfellhytta Reindeer Viewing Pavilion, Snøhetta designed a raw steel box, open on its two opposing sides contrasted with an elaborate carved wood wall that provides

159

Why Carve?

FIGURE 3.19 Stone panels installation. Photo: Frank Vincentz [CC BY-SA 3.0 (https:// creativecommons. org/licenses/by -sa/3.0)].

FIGURE 3.20 Carved wood wall and bench at Tverrfjellhytta. Photo: Ketil Jacobsen, courtesy of Snøhetta.

seating on the exterior and interior (Figure 3.20). Te wood assembly appears as an eroded timber object shaped to create seating and held inside the metal box. Te thick wood wall is composed of 10-inch square pine timber beams oiled on the interior and protected with pine tar when exposed on the exterior. Set in the cold Norwegian climate, the carved wood assembly is essentially a large furniture component providing a place of warmth from which to view the outdoors. Te wood assembly appears as a massive chunk of eroded wood. But in actuality, the wall assembly is a hollow steel framework clad with milled timber members to appear as a single eroded mass. Trerrfellhytta efciently uses one layer of 10-inch square timber to cre­ ate the overall interior topography. Te form of the wood assembly was 3D modeled so that

160

What Happens When Carving?

FIGURE 3.21 Section of the wood timber assembly. Photo: © Snøhetta, courtesy of Snøhetta.

only a single layer of timber beams would be required. On the outer face of the wood wall, individual timber elements shift to minimize the amount of wood needed to create the complex curved form (Figure 3.21). Snøhetta relied on the expertise of Norwegian shipbuilders to carve the timber assembly’s unique form. Te traditional method of using wooden pegs as fasten­ ers joins the timber members together and then the assem­ bled timber is milled as a larger unit. Te milling machine leaves traces on wood surface. Tis smaller scale texture reveals the path of the mill onto the timber assembly (Figure 3.22). Te face of each timber is milled to achieve its eroded and organic shape. Te remaining three sides of the timber component are fat along its length so that the timber can be easily attached to a supporting structure. Te carved wood is brought to the site in several units and then set into place as a unifed assembly. Te carving strategy used at Trerrfellhytta is a strategy of assembling the timber components into a larger unit and then milling it. For the Grotto Sauna, Partisans Design Studio created an eroded interior topography, but in this project, each wood panel, varying in shape and size, is carved independently and then assembled on site. On the exterior, the sauna is a simple wood box embedded into a natural rock landscape. Partisans Design Studio devel­ oped a new process of fabrication that used a 3D scanner to get precise site topography so that the entire sauna assembly could be prefabricated and then attached to the foundation on site. Te wood façade panels are vertically oriented and charred using the Japanese shou sugi ban treatment. In contrast, a total of 117 northern white cedar wood panels are milled and the direction of the wood grain was consistent to create the illusion of a uniform carved interior.

FIGURE 3.22 Interior view of the carved wall at Tverrfjellhytta. Photo: Ketil Jacobsen, courtesy of Snøhetta.

161

Why Carve?

On the sauna interior, each 7.5-inch-deep wood panel is completely unique. Te panels curve to form an organic interior environment integrating seating, windows, and other functional needs. Te sanded-smooth wood panels are supported on a hidden galvanized steel structure. Since the space is a sauna, the wood is expected to expand and contract. Partisans Design Studio focused on added details of joints and reveals between the panels to accommodate movement in the wood. Because each wood panel is unique in form, this meant that each panel had to be installed in a specifc order. In order to carve the wood panels precisely and to make efcient use of materials, Partisans Design Studio worked with fabrica­ tors to override the limitations of the CNC milling machines. Tey did not let the machinery dictate their design. In another Partisans Design Studio project, Bar Raval also has a carved mahogany wood paneled interior with complex curved forms. Te hand-oiled carved wood clads the entire interior of the bar. Te organic geometry is functional in that it accommodates storage spaces, integrates bowls, and curves to encourage comfort for patrons. Instead of smooth sur­ faces, the wood panels were designed with a continuous rib texture to capture a sinuous and muscular character in the wood panels. Like the Grotto Sauna, each wood panel is unique in shape and size using a fve-axis CNC mill. To produce a continuous interior surface, the ribbed pattern needed to align between panels. Te ribs added dimension and could also help create rigidity for the panels. But the variation in thicknesses of the ribs at panel edges could cause warping and shrink­ age of the wood. Aligning the rib pattern between panels was difcult due to the complex geometry of each panel. Partisans Design Studio made design adjustments in the panels dur­ ing fabrication and construction to align the rib patterns. To prevent warping and shrinkage in the wood, the angle of the seams between panels had to be perpendicular to the carved surface. Te wood panels would ft together like a puzzle as it fastened to a supporting steel framework. At the storefront window, the wood panels are supported on laser cut steel panels which adds another layer of detail to the bar interior. Building materials like wood and stone have an inherent organic composition and they have to be shaped through a process of cutting and removing the material. In using wood and stone in building assemblies, the most common and simplest process is to make straight cuts and then address the fnished surface texture of the material. To carve the mate­ rial further seeks the unexpected in those typical building material components. Te opera­ tion of carving is not just for decorative purposes. It can have more important functions in increasing the surface area of the material to difuse natural light and to create depth in the façade.

Ornamentation and Stability: How Do We Maintain and Express Structural Integrity in Carving? We have just discussed carving building materials as cladding components. In this section, we look at building materials carved to function as structural components. Carving does not just create complex geometry for appearances, but cutting materials increases the surface area so that individual components work together as a whole structure system. Te following pro­ jects carve materials in innovative ways for structural functions and for expressive structural components. Material is subtracted when it is not needed for structural integrity.

162

What Happens When Carving?

At the scale of the component, the façade panels in Snøhetta’s SF MOMA addi­ tion are generated from a carved mold to provide structural shape and ornamentation. Tis project is the frst building in the United States to use exterior façade panels made of fberglass reinforced polymer (FRP) (Figure 3.23). In preliminary design proposals, Snøhetta looked into producing the façade panels using glass fber reinforced concrete (Ductal). Working with the fabricator Kreysler Associates, the concept of using foam and FRP was a lightweight alter­ native for the façade. It is critical to note the importance of considering diferent construction operations. Design ideas can materialize in any number of ways, so thinking through the options allows for innovative possibilities. Since FRP was a new material for building façade panels, the project went through rigorous fre testing to demonstrate that the FRP was a suitable application. Each of the 700 one-of FRP panels were shaped using milled recyclable expanded polystyrene (EPS) foam molds. Te maximum size of the panels was approximately 5 feet by 29.5 feet (1.5 meters by 9 meters). Te wavy pattern carved into the foam contributed to the structural integrity of each façade panel. Te FRP material was laid over the milled EPS foam panels to create a composite panel. Te surface of the panel was a layer of sand and resin mix, and then it was overlaid with three layers of woven glass fber roving with resin impregnator. In total, the FRP surface is 3/16 inches thick for the cladding panels. Aluminum tubes were added to the back of each panel to give additional structural rigidity and to provide a fat surface to attach to the building structure. Te EPS foam was used during transport to protect the panels, but then the foam is recycled. Experimenting with materials and assemblies often requires the strategic combi­ nation of various operations. CNC milling materials such as EPS foam is a typical step for shaping molds or prototypes. In these carved materials and forms, the structural integrity comes from its role as a supporting component. Likewise, innovative techniques can also come from new strategies based on traditional techniques. Japanese joinery is well known

FIGURE 3.23 SF MOMA façade. Photo: Kazuyo Oda.

163

Why Carve?

for carved timber members and interlocking these members into a unifed structural system without the use of fasteners or additional materials (Figure 3.24). Te subtraction of material is precise in its geometry and form in order to interlock members and distribute structural forces and loads. Shigeru Ban’s Tamedia Ofce Building is a modern variation on traditional Japanese wood joinery applied to an unconventional glu-lam timber structure for an ofce building. Te seven-story wood post and beam structure of Tamedia is an assembly of carved timber components interlocked together. Tis primary structure is composed of 1,400 untreated timber pieces and using a CNC mill, each timber piece is rounded at its ends to express the interlocking joints (Figure 3.25). Long structural members are spruce wood and each 18 foot (5.5 meters) long cross beam is milled in an oval cross section for a more rigid structure. Like the traditional Japanese approach, no fasteners or adhesives were used. To lock together the softwood timber, the joint pins are carved out of beechwood, a durable hardwood. Tere is no steel in the entire timber structure. Tamedia’s structure is a series of timber frames using four 69 feet (21 meters) posts and fve 57.5 feet (17.5 meters) double beams. Te timber frames are then connected with the pins and the rounded cross beams. Te timber elements are prefabricated and then assembled on site. Te form of timber structure stands out from the other building materi­ als (Figure 3.26). Te orthogonal building elements negotiate between and cut around the rounded structural components. Wood gives the building warmth and carving the wood into rounded shapes emphasizes a visual contrast between the wood and the rest of the building. On the interior of the ofce building, the timber structure has a dominant presence. On the exterior, the glass façade shields the timber structure, but the façade has retractable windows that open to reveal the timber structure. Ban used timber because it is a renewable construc­ tion material and a sustainable option. To produce the 70,600 cubic feet (2,000 cubic meters)

FIGURE 3.24 Typical Japanese wood joinery struc­ tures. Photo: Lisa Huang.

164

What Happens When Carving?

FIGURE 3.25 Detail of Tamedia structure. Photo: Lisa Huang.

of timber structure, 127,130 cubic feet (3,600 cubic meters) of spruce were milled, so almost half of the wood gets carved away. In contrast to the large-scale structural components in the Tamedia building, Kengo Kuma carves small-scale wood components aggregated into a building assembly that is both structure and enclosure. At SunnyHills, Kuma uses a modern version of traditional Japanese joinery methods called jigoku-gumi where wood components intertwine into a complex interlocking structure. SunnyHills uses cypress wood elements that are 2.36 inches square (60mm × 60mm) in cross section. Wood is carved out in 30-degree and 60-degree angles so that wood elements interlock into a single three-dimensional structure. All the ele­ ments combine to act as one woven or knitted unit (Figure 3.27). Te wood assembly is composed of two layers of wood that crisscross to interlock into a plane. Ten two vertical planes of crisscrossed wood members are interlocked with a third wood component creating a three-dimensional structure (Figure 3.28). Traditional Japanese joinery carves the wood with chisels and the joints do not use nails or adhesives. In SunnyHills, Kuma wanted the wood to be extremely thin, so the intersecting members are secured with a hidden screw and then steel plates and metal pins are used to reinforce the interlocking joint. Te wood was carved to accommodate the interlocking joints and to hide

165

Why Carve?

FIGURE 3.26 Lobby at Tamedia Offce Building. Photo: Lisa Huang.

connections. Each wood piece has a precisely cut groove to achieve a tight ft between wood components. At the carved surfaces, the wood components exert forces on each other. Te notches provide more surface area encouraging the material to absorb structural forces. Te subtraction of material maximized the material’s ability to contribute to a larger whole. Each step in the construction of the wood structure was very systematic. Te concept of jigoku­ gumi implies that every single component was vital and if one component was removed, it would destabilize the entire structural system. Another project where carved components rely on each other to create a structure is Höweler + Yoon’s MIT Sean Collier Memorial. In this project, 33 granite blocks are carved to structurally support each other and to defne a space of remembrance (Figure 3.29). Te memorial is 36 feet in length and 28 feet in width and fve stone arches meet in the center vault to form a central ovoid space. Te inside surface of the ovoid is honed smooth, while the exterior stone edges are a famed texture. Te memorial uses the traditional structural technique of stacking masonry to distribute weight and form an arch. However, Höweler + Yoon challenge the traditional masonry structure by setting the center stone frst during

166

What Happens When Carving?

FIGURE 3.27 Wood façade of SunnyHills. Photo: Lisa Huang.

FIGURE 3.28 SunnyHills wood structure detail. Photo: Lisa Huang.

construction. Te central stone is not the key component that structures the arch form. Each stone block in the assembly contributes to supporting the arches. Te shape of each stone block was determined by the equilibrium in the whole assembly. Höweler + Yoon produced numerous physical material models using foam, wood, and 3D prints to test the shape of the unit and the whole composition. Stone itself is a stable and rigid material, but since the shape and size of each block was unique. Every stone block was hand-picked from the quarry. Tis ensured the stones would not have faws that could

167

Why Carve?

FIGURE 3.29 Sean Collier Memorial at MIT by Höweler + Yoon. Photo: Fred Gutierrez.

FIGURE 3.30 Collier Memorial stone cut with precision. Photo: Fred Gutierrez.

afect the structure stability. In the operation of carving the stones, a combination of saws, CNC mills, and robotic milling machines were used to cut the stones extremely precisely. In this project, the joint between stones carried structural forces. Te joints were cut perpen­ dicular to the lines of thrust to keep the whole stone assembly stable (Figure 3.30). Steel pins were added between some of the stones in case any shifts occurred due to unforeseen forces. Te stones had to be carved to a 0.5 mm tolerance. During the fabrication process, cutting tools would wear down and consequently afect the tolerance, so Höweler + Yoon would have to adjust the digital model in parallel with fabrication so that the next stone components would be carved to match.

168

Chapter 4

Why Stack?

4.1

What Can We Stack?

Te assembly technique of stacking materials is essentially a series of building modules placed one upon another to create a monolithic and uniform construction. Te key material con­ siderations for stacking revolve around the simplicity of the construction technique. It is a low-tech assembly strategy that does not require the use of special equipment. In stacked assemblages, the size of the components is scaled to the human body. Human hands can pick up each module without the use of mechanical equipment and set the module into place. We often consider stacked materials to be intimate and relatable because each individual building module is proportioned to a size that we can grasp. Te construction of a brick wall is visible in its outward appearance. Te aesthetic of a stacked wall directly reveals the process of making the wall. Because each module in a stacked assembly helps carry the weight of the whole assembly, the material used for the module needs to be strong and capa­ ble of handling the cumulative weight of the bearing assembly. Also, typical materials used for stacking like stone and fred clay are inherently heavy, solid, and stable in character and appearance. Te assembly method of stacking has deep-rooted historical signifcance as one of the earliest methods of construction. Structures built using stacking techniques have lasted for centuries. Te pyramids in Djoser, Egypt from the 27th century BC are the earliest largescale cut-stone construction (Figure 4.1). So many of our iconic historical structures across the world such as the Mayan ruins and the Great Wall of China are all still structurally intact. From these structures, we understand stacked assemblies as durable constructions that can withstand the test of time. Institutional projects like university buildings are often stacked brick constructions to project the appearance of permanence, monumentality, and massiveness, yet because of the natural material and intimate scale of the material, the stacked construction still conveys familiarity. When we think of stacked assemblages, brick and stone are the most common materials. However, stacking modules can include other regional materials like adobe blocks and timber to manufactured products like concrete masonry units and glass blocks. Stacking materials even include unconventional or salvaged objects. Basically, any material that is modularized and able to bear weight can be stacked. With all these material options, there is

171

Why Stack?

FIGURE 4.1 Pyramid at Djoser. Photo: Sharp Photography: Charles J Sharp.

also the possibility of creating texture on stacked surfaces. Te production processes of stack­ ing modules vary greatly and can impact the aesthetic decisions in a building design.

Typical Stacked Materials and Components Stone is quarried from the natural environment. Large blocks of stone are carved out of the earth, then shipped to production facilities that cut the stone into standard construction sizes and fnish the stone face to a desired surface texture (Figure 4.2). Stone is cultivated in numerous locations throughout the world with large variations in color and hardness.

FIGURE 4.2 Stone quarry. Photo: Mahlum.

172

What Can We Stack?

Granite is the hardest stone available for construction while the other end of the spectrum consists of sandstones. Both hard and softer stones can be used in stacked block construc­ tion. A range of diferent stone surface textures can be polished, honed, famed, or left in its natural cleft. Fieldstone is collected in its natural form and used in dry stacked construction. No manufactured procurement is necessary for feldstones. Historically, structures used stone blocks as load-bearing walls, but in contempo­ rary construction, stone is more commonly used as a veneer cladding. Tin sheets of stone are fastened to a back-up structural wall. In the Ohel Jakob Synagogue designed by WandelHoefer Lorch and Hirsch, the stone building façade looks like a stacked assembly of largescale travertine blocks with an undressed natural cleft surface. Each stone’s dimensions are consistent in height but varies in width stacked in a running bond pattern (Figure 4.3). Te building’s appearance conveys a monolithic construction with stone blocks assembled into the bearing wall construction. However, the travertine stone is a cladding. Each stone mod­ ule is not bearing weight onto the stones below; it is a thinner cut of stone fastened to the bearing wall structure. Tis historical shift from structural to cladding conserves material and simplifes construction labor. Stone is a limited natural resource and it is relatively more expensive than other building materials. Contemporary construction technology has evolved to be more efcient and to save on material costs. Adobe bricks are mud modules composed of several natural materials such as earth (sand, clay, and silt), water, and an aggregate of straw to help avoid extreme shrinkage in the drying process. Typically, the adobe mixture is pressed into a simple wood mold. Te wood form is removed and adobe brick is then air- and sun-dried, frst fat on its broad face and then on its edges to evenly dry (Figure 4.4) After several weeks of drying, the bricks are ready to use. As an alternative to stacked blocks, adobe mixtures are also used to form walls at a large scale. An adobe assembly is an excellent thermal mass – cool in summer and warm in winter – but it is not a good insulating material. A continuous layer of adobe is typically spread on the outer edge of stacked adobe wall to protect the entire assemblage (Figure 4.5). Adobe is one of the oldest and most basic building materials, but it is material that only works for dry and warmer climates. It is a common building material in the southwestern

FIGURE 4.3 Stone façade at Ohel Jakob Synagogue. Photo: Lisa Huang.

173

Why Stack?

FIGURE 4.4 Adobe bricks drying in Chiapas Mexico. Photo: Lisa Huang.

FIGURE 4.5 Great Mosque at Djenné in central Mali. Photo: Ruud Zwart.

region of the United States even in the present day. Stacked adobe is an inappropriate con­ struction strategy universally since adobe bricks are sun-dried. Te material composition of adobe does not transform, so the climate needs to support the integrity of adobe to maintain the assembly. If the climate is prone to wet conditions, adobe bricks could return to its origi­ nal consistency. In addition, since adobe bricks will shrink and swell with the weather, any freeze and thaw conditions could break up the bricks. Tere is a newfound interest in adobe brick masonry because it is a low-cost and sustainable construction. Like adobe brick, masonry brick is formed with a base of clay and silt, but bricks are fred at high temperature to create a fre-resistant and permanently stable building material.

174

What Can We Stack?

Te material composition of bricks can vary to achieve a range of colors and textures. Brick properties can be manipulated, whereas the composition of stone is a found condition. Bricks are molded or formed and then fred in a kiln. Te fring process of the brick changes its material composition and makes it a more universally standard construction material. Te standard size is the modular brick which has an actual dimension of three and fve-eighths of an inch × two and one-quarter of an inch × seven and fve-eighths of an inch. Mortar makes up for the remaining three-eighths of an inch thickness in the assembly to make it a nominal four-inch × two-and-a-half inch × eight-inch module. A brick module can be easily custom molded or extruded into diferent shapes. Once a brick is fred, it is noncombustible and impermeable to water. Bricks are sized to the human hand and the small size makes it less likely to crack during the process of drying and fring. Te size of brick is also easy to adapt to small-scale geometries and patterns in building forms. Te important qualities to consider when selecting bricks are the molding process, color, size, durability, and general uniformity in appearance. Bricks are manufactured into standard sizes but even with modernized and standardized manufacturing processes, every brick is still very individual in appearance. Each brick from the same batch of ingredients and fring is not identical or perfect in form. With bricks, the expectations of uniform appear­ ance, perfectly straight edges, or identically colored cannot be controlled. Te standard size, form, and quality are approximate because of a number of factors. Bricks are produced in an automated process where the clay material is extruded, pressed or molded, dried, and then fred. Bricks are made from primarily natural materials that have inherent inconsistencies. Te addition of admixtures can also produce a range of colors and textures. Even though brick production is automated and standardized, each brick is still unique and it is difcult to produce completely identical bricks. In taking a closer look at a brick wall, the individuality of the brick is what makes the wall more interesting. From a distance, the stacked brick assembly looks like a unifed whole, but upon a closer examination, there are variations of color and texture of each brick like a pixelated surface. Clinker bricks are an example of the extremes in brick production. Te location of a brick in the kiln can change its aesthetic characteristics and material composition. Clinker bricks are a result of the fring process where the bricks that are too close to the fre get burnt and irregular in shape, color, and texture. Clinkers are named for the glass-like sound they make. In these ‘overcooked’ bricks, the sand com­ ponent in the clay mixture melts and transforms to glass. Tese bricks are normally con­ sidered unusable, but many architects have incorporated clinker bricks into their stacked assemblies. Alvar Aalto’s Baker House at the MIT campus and Eero Saarinen’s MIT Chapel both used clinker bricks in the masonry assembly for texture and shadow. For the Baker House, Aalto went to the brickyard and handpicked the clinkers that would create shadows and texture in the large masonry façade (Figures 4.6 and 4.7). At the MIT Chapel, the bricks were handmade using a water-struck technique that was a common method in New England (Figures 4.8 and 4.9). Bricks were hand-molded and used a high content of water to slide bricks out of their wood molds, thus leaving a unique texture on the brick faces. Water-struck bricks are sun-dried and then baked in a kiln. Te process yielded an even wider range of vari­ ation and irregularity in the color and texture of the bricks. It is not mechanically produced, but they were more likely to have inconsistency in shape. Due to their distorted form, bricks

175

Why Stack?

FIGURE 4.6 Baker House facade with intermittent clinker bricks. Photo: Daderot [Public domain].

FIGURE 4.7 Close-up of clinker brick at Baker House. Photo: Tom Ring.

like clinkers are more difcult to set into the stacked wall because the mortar has to fll in the inconsistent dimensions between the deformed clinker bricks. Brick is historically a common material in stacked bearing wall constructions. But often in contemporary constructions, the stacked brick seen on building facades are actually brick veneer cladding. In an efort to save on material and labor costs, brick may be a thin veneer set on a precast panel that is then fastened to a back-up wall. Te illusion of stacking brick is captured in the appearance of the cladded assembly, but it may not refect the actual construction. Stacked masonry assemblies openly express a load-bearing construction system, but as veneer cladding, the bricks do not bear weight on each other.

176

What Can We Stack?

FIGURE 4.8 MIT Chapel interior masonry wall. Photo: Fred Gutierrez.

FIGURE 4.9 MIT Chapel exterior masonry wall. Photo: Fred Gutierrez.

177

Why Stack?

Concrete masonry units, known as CMU, are also a common precast building module type used in stacking. Concrete is a material that has been historically prominent, but the precast concrete block is a relatively modern building component developed in the 19th century. CMU blocks consist of cement, water, sand, and gravel molded in automated processes and then cured. Since the module is made of concrete, it does not need to be fred like brick. Concrete blocks are manufactured in various standard sizes, but the typical eightinch CMU module has the actual dimension of seven and fve-eighths of an inch × 15 and fve-eighths of an inch × seven and fve-eighths of an inch. Like brick, a three-eighths of an inch thickness of mortar is calculated into the nominal module size. Concrete blocks are usu­ ally hollow to lighten the weight of the block and to provide space for added steel reinforcing and insulation. Concrete blocks have fat faces, but surface variations such as split-face and ribbed are available. Concrete blocks are porous, so often the surface of a concrete block wall requires a layer of stucco to provide a protective surface that consequently hides the stack­ ing pattern. Te material and scale of the CMU block give it a more industrial appearance. Rectangular or cube blocks are typically used in back-up wall assemblies, but CMU molds can be customized into diferent shapes, sizes, and surface textures. In the AU Ofce and Exhibition Space, Archi-Union Architects use the hollow core of the concrete block to create an undulating façade (Figure 4.10). Te wall is a single wythe of CMU blocks with approximate nominal dimensions of an eight-inch cube. Te void within the CMU, which is typically hidden, rotates perpendicular to the face of the building to produce a screen wall. Te blocks rotate in a pattern that creates an organic surface texture. Te directional changes of the CMU openings consequently cast light dynamically into the building. Te stacking pattern for the CMU was a digitally generated parametric surface. Te entire assembly used ten templates to lay out the wall’s geometry. Te complex layout of the stacked assembly highlights an issue: How do we apply mortar if the orientation of each adjacent brick is not aligned? To perfectly match mortar to CMU interfaces would be a complex and time-consuming process. Here, a layer of mortar is applied uniformly on top of each CMU block to eliminate the problem of placing mortar exactly in the overlap between blocks. Excess mortar sits on top of every block, but the entire assembly appears consistent.

FIGURE 4.10 Overall façade of CMU modules stacked. Photo: Archi-Union.

178

What Can We Stack?

Concrete block is generally a low-cost building component. In 1923 and 1924, Frank Lloyd Wright built a series of textile block houses, including the Charles Ennis House and the Alice Millard House, which experimented with concrete block assembly. Wright reimagined the reinforced concrete wall by composing the wall with stacked concrete blocks in more elegant proportions than CMU. Precasting concrete in smaller units allowed for more precise articulation and detail in each block’s surface. Acknowledging that concrete’s strength is in compression, each block was essentially stacked to exert its weight on the blocks below. As a result of experimenting with a new construction strategy, there were numer­ ous lessons learned in these projects. In the Ennis House, Wright designed a custom formwork to produce 16 inch × 16 inch × three-and-a-half inch concrete blocks. Te wall assembly was two layers of the concrete block, one exterior facing and the other interior facing, with a steel reinforcing frame embedded between blocks. In the Ennis House construction, the steel structure is hidden within the assembly and the relatively thin concrete blocks exert weight on adjacent blocks (Figure 4.11) Te material of the formwork, whether wood or aluminum, afected the dimensional consistency of the block’s form. Te material composition of the Ennis House concrete blocks used aggregate from the site, but unfortunately, it contained decomposing granite. Tis consequently produced a weak material composition for the concrete. Te faulty concrete mixture likely contributed to premature decay of the concrete modules. Te thin blocks located at the base of the house very quickly cracked in bearing the weight of the assembly. Numerous attempts have been made to preserve the weathering and aging of the Ennis House blocks. At one point, a protective coating was applied to the concrete blocks to help the integrity of the concrete composition. But instead, it resulted in faking and peeling at the face of the concrete block. A glass block is a hollow module of glass molded or formed in two parts, then fused together along a central seam. Glass blocks stack like most masonry installations. Mortar is used to adhere glass blocks together into an assembly. Vinyl is sprayed on the edges

FIGURE 4.11 Detail of concrete panels at Ennis House. Photo: Geek_Love_13.

179

Why Stack?

of each glass block in the manufacturing process so that the mortar adheres better. Te edges of glass block also recess inward to create space for setting reinforcing steel bars between the blocks. A typical glass block has a nominal size of eight inches or six inches square. Te actual dimension of a nominal eight-inch glass block would be seven and three-quarters of an inch to account for the one-quarter-inch thickness of mortar. In the early 20th century, hollow or solid glass blocks were set into horizontal or vertical surfaces to transmit light into a space. In Pierre Chareau’s Maison de Verre, glass appears as a masonry module stacked to create a translucent façade. Tis three-story façade would provide maximum natural light for the infll site condition (Figure  4.12). In 1927, Chareau had been experimenting with thick frosted glass lenses as the primary material for large translucent walls. Glass modules were untested for protective weather enclosure. For the Maison de Verre, Chareau opted for a Nevada-style glass lens, 7.8 inches × 7.8 inches × 1.5 inches, that had a thin concave surface. It was not a hollow glass block, but the module had a groove along its edges to hide the structural reinforcing system. Like with the Ennis House, Chareau used a thin module, but the glass lens had substantial steel structure that distributed material weight. Te steel framed the façade into sections that contained three to six rows of glass block with hidden steel reinforcing. Te façade operates like a curtain wall system rather than a masonry assembly.1 Te glass modules do not exert any weight directly on glass modules below (Figure 4.13). Glass block was an extremely popular accent building material in the 1970s to the early 1990s. It was often used as infll within a wall. Because glass block was so prevalent then, the material is often associated with a dated postmodern aesthetic. As we see in Maison de Verre, glass block is aesthetically more impactful when the entire façade is stacked with

FIGURE 4.12 Glass lens façade at Maison de Verre. Photo: Trevor Patt.

180

What Can We Stack?

FIGURE 4.13 Close-up of the glass lens. Photo: Trevor Patt.

FIGURE 4.14 Glass block façade at Maison Hermes. Photo: Woranol Sattayavinji.

glass block. Renzo Piano’s Maison Hermes in Tokyo uses 13,000 glass blocks for the entire building façade (Figure 4.14). Piano changes the proportion of the glass block into a custom size so it is bigger than standard glass block dimensions. Two block dimensions were used: 17 inches square and a half-size of eight-and-a-half inch square used at the rounded corners of the building (Figure 4.15). Flexible seals, set into the joint between each block, absorb lateral forces anticipated from earthquakes. Piano created an innovative façade structure where the stacked glass assembly is mounted on a steel framework that is hung from steel structural cantilevered of the primary building structure.

181

Why Stack?

FIGURE 4.15 Glass blocks at the edge and corner of Maison Hermes. Photo: Lisa Huang.

When we consider stacked wood components, the rustic log cabin represents the prototypical construction. Te ends of timber logs are notched so that when the logs stack, they interlock at the corners and hold together the assembly. To avoid rot and mold, the roof eaves extend out past the assembly surface to keep water away from the timber. Te wood may also be treated or the gaps between logs may be sealed to provide more thermal enclosure. Te typical log cabin stacks along the length of wood, but stacking of wood mod­ ules can occur in the opposite orientation that exposes the end grain. Cordwood masonry, another regional construction technique, stacks the timber logs like brick modules. Each log segment is adhered with mortar and stacked with the end grain exposed. Te mortar for cordwood masonry usually incorporates sawdust to produce a more insulating joint. In this type of stacked assembly, a long timber log is not needed and it is easier to conserve wood by using scraps or recycled wood. As a result, cordwood masonry usually produces a thick structural wall assembly. Studio Gang’s Arcus Center for Social Justice Leadership located at Kalamazoo College in Kalamazoo, Michigan uses cordwood masonry construction to form the building’s exterior and brings a progressive approach to this regional technique. Log sections typically 11 inches in length with varying diameters and natural variation in color are set into mortar in a seemingly random pattern (Figure 4.16). Te end grain of the logs is exposed on the exterior surface, creating a cladding for the building. Te thickness of each module provides additional thermal protection in the wall assembly. At the scale of the build­ ing, the modules of cordwood masonry easily negotiate the curved façade of the building. Te pattern of their cross sections is coordinated with the location and shape of the building’s windows. To create larger apertures and thresholds in the building, the cordwood modules shift outward, producing curved surfaces on the vertical axis in the façade (Figure  4.17). Te white cedar logs were harvested in-state and because they require minimal processing, they actually sequester more carbon than was emitted in their production. Although it is not a universally common construction method, cordwood masonry is a highly thermal, lowcarbon, and economical assembly option. Te Arcus Center demonstrates that using stacked wood does not have to be exclusively rustic in appearance.

182

What Can We Stack?

FIGURE 4.16 Cordwood masonry construction at Arcus Center for Social Justice Leadership. Photo: Courtesy of Studio Gang.

FIGURE 4.17 Shifted cordwood modules to form windows. Photo: Steve Hall.

Atypical Stacking Materials and Components Te strategy of stacking is a very straightforward construction operation. Essentially any component of a manageable size can be stacked to create a wall. Te assembly just requires a large quantity of that material component. Many architects have found innovative ways to stack atypical construction materials and recycled building materials. Clay roof tiles are typical overlapping shingles on rooftops, but both Amateur Architecture Studio and Arturo Franco Ofce for Architecture brought new life to salvaged

183

Why Stack?

building components by reusing them as stacked modules. In the Ningbo Historic Museum, Amateur Architecture gathered numerous types of abandoned building materials made of clay and stacked these materials to produce an intricately patterned façade cladding (Figure 4.18). Tis Chinese construction technique called Wapan masonry is a method of assembling a wall rapidly using found building materials. Te museum’s façade uses gray and red roof tiles and bricks of various sizes and dimensions. Items like curved molding and bricks are inserted within the stacked cladding patterns. From a distance, the reclaimed materials appear as land­ scape compositions of colors. Up close, the stacked modules are marvelous constructions. Every odd shaped building module has its place, tightly set in the assembly (Figures 4.19 and 4.20).

FIGURE 4.18 Reclaimed building materials in the Ningbo Historic Museum facades. Photo: Xuancheng Zhu.

FIGURE 4.19 Details of the stacked facade assembly. Photo: Xuancheng Zhu.

184

What Can We Stack?

FIGURE 4.20 Photo: Xuancheng Zhu.

In the Matadero Warehouse 8B project, Arturo Franco stacked reclaimed roof tiles into interior partitions. (Figure 4.21). Te clay tiles have a turned-down ledge on one end which would be used to attach the tile to the roof. In the Warehouse 8B project, Franco reorients the tile to celebrate the tile’s three-dimension form. Mortar was selectively used to not only bind the clay tiles but to also create space between the tiles. Tis added shadow and depth to the interior screens. Te three-dimensional roof tile form was cleverly stacked to also allow movement of light and air through the assembly (Figure 4.22). In both these projects, the reclaimed materials are seen in an innovative way and create beautiful new masonry pat­ terns and textures revealing the typically unseen portions of building materials. Te work of Rural Studio is known for its creative use of reclaimed or found materials. Rural Studio has also reimagined stacked assemblies with all kinds of materials like baled cardboard or stacked plywood on its end grain. Stacking materials does not require complex construction equipment, so they have experimented with a range of salvaged and donated material components. In the Lucy Carpet House, 72,000 salvaged carpet tiles were furnished by modular carpet company and individually stacked to construct the walls of a 1,200-square-foot house (Figure 4.23). Te stacked carpet assembly is aligned with vertical steel rods and held in compression by a heavy wooden ring beam at the roof edge. Te steel reinforcement rods embedded inside the carpet assembly carry the structural load of the roof and relieve the carpet of any structural responsibility. Rural Studio conducted a series of material tests and found that the 18-inch-thick carpet walls had high insulation values with­ out the need for additional insulation. Teir material tests also demonstrated that the carpet was fre, water, and bacteria resistant. In Rural Studio’s Yancy Tire Chapel, salvaged tires were stacked to create retain­ ing walls and to support a wood roof structure. Nine hundred tires were stacked, tamped with dirt, and tied together with rebar. Te chapel is an open-air structure, so the project did not have to address issues of thermal protection and weather-tightness. Stucco was applied over the stacked tires to unify the appearance of a monolithic assembly. Te visible shape of

185

Why Stack?

FIGURE 4.21 Interior walls com­ posed of stacked roof tiles created at Matadero Warehouse 8B. Photo: Carlos Piñar, courtesy of Arturo Franco.

each tire is evident, but the tire’s rubber material is obscured. Sealing the stacked assembly with a layer of concrete stucco not only hides the tires but also protects the material compo­ nents from water infltration and material deterioration. Often stacked assemblies are covered in a protective layer, especially if the stack­ ing module is vulnerable to deterioration. Te Bryant Haybale House used 24-inch wide hay bales stacked into the house walls. Since hay is an organic material that is susceptible to decay when exposed to air and water, an applied layer of concrete helps to preserve and pro­ long the organic material’s life span. Rural Studio also tested cardboard in a housing pod on their Newbern Alabama home base. Wax-impregnated corrugated cardboard clippings from construction sites were recycled, bundled, and then stacked to create a walled enclosure for a residential unit. Te cardboard soaked in wax created a protective barrier that resists and maintains its strength against moisture. Te cardboard bales are stacked in a running bond pattern to perform as both foundation and bearing walls for the housing unit (Figure 4.24). Tese projects demonstrate to us that any material can be bound together and become a stacking module.

186

What Can We Stack?

FIGURE 4.22 Details of roof tile assembly. Photo: Carlos Piñar, Courtesy of Arturo Franco.

Key Issues to Consider in Material Selection Brick is the most common material used in stacked assemblies, but there is a wide range of available materials. Te keys to a stacked assembly are using a building component that is easily installed by hand and implementing a simple construction process where each mod­ ule bears weight on another creating a stable assembly. If a stacked assembly is used for an exterior wall, the module material must address concerns of water resistance, fre resistance, and thermal insulation. If a stacked assembly is used as an interior wall, water resistance and thermal protection are less of a concern. Stacking is a straightforward method of construction because each building mod­ ule tends to be a small component. A small sized module is less likely to crack and a per­ son can assemble these modules without the help of mechanical equipment. Inherent in the module size and a hand-produced construction method, the stacked assembly has an easily relatable scale. Stacked assemblies can appear massive, monolithic, and heavy, but it is not imposing because of the module’s intimate size and through variations in the texture and pattern in stacking.

187

Why Stack?

FIGURE 4.23 Lucy Carpet House by Rural Studio. Photo: Timothy Hursley.

FIGURE 4.24 Cardboard Bale House by Rural Studio. Photo: Lisa Huang.

Two primary factors impact the texture of a stacked assembly: the characteristics of each module (the design of the module itself) and the coursing patterns of the modules (the arrangement of the modules in relation to each other). Although there are standard sizes for modules like brick and glass block, these mechanically produced components are easy to customize in form and surface texture. Te die or formwork to make molded or extruded

188

What Can We Stack?

FIGURE 4.25 Young Vic Theater brick façade tex­ ture. Photo: Lisa Huang.

modules can be customized. If stacked assemblies are using large quantities of material, the module customization can be a repetitive and cost-efcient process. Altering the masonry module has implications. Te ‘folded’ brick shape in Haworth Tompkins’s Te Young Vic Teater creates more texture and shadows at a smaller scale and the geometry of brick creates an interesting corner condition for the façade. Te varying surface depths of the brick face impacts typical methods of tooling mortar joints (Figure 4.25). Like the three-dimensional geometry of the AU Ofce and Exhibition Space façade, brick modules producing three-dimensional surfaces in the stacked assembly require more efort in applying and tooling the mortar joint. In the Young Vic Teater, the overall efect of the wall is beautiful, but each brick has a small ledge, so masons have to invest more time in constructing a clean assembly. At the scale of the building, the coursing of modules creates patterns in the stacked assembly. More commonly, stacked assemblies have fushed surfaces for efciency of con­ struction. Flush edges of brick allow quick and easy tooling over the surface. However, many architects have experimented with rotating or shifting modules within the assembly in order to create greater three-dimensional and shadow efects in the stacked surface.

Note 1

Esther da Costa Meyer, Pierre Chareau: Modern Architecture and Design, (New York, New Haven: Te Jewish Museum, Yale University Press, 2016), 185–186.

189

How Do We Stack?

4.2

Typical Assembly Requirements Local resources and vernacular traditions largely determined the materials and methods of stacked construction. Stacked wood assemblies would be more common in regions where timber is abundant. Bricks and adobe blocks are easy building materials to produce with­ out complex equipment. Tey are often a common and inexpensive building material when alternative materials are difcult to source. Bricks can be easily made in most places where clay is present in the soil. Te primary material for sun-dried adobe blocks and fred bricks can be extracted directly from soil. Waste products like coconut husks can be used as rein­ forcement within the module. Kilns to fre the bricks could be fre pits dug into the ground (Figure 4.26). Te simple beauty in the process of making these building components reveals

FIGURE 4.26 Kiln for fring bricks in Chiapas Mexico. Photo: Lisa Huang.

190

How Do We Stack?

the honesty in the construction assembly. Te module can directly display the process of making. Stacked masonry systems are an accessible, economical, and easily implemented form of building construction. It is a simple assembly of manageable building modules that do not require fancy equipment. However, it is a labor-intensive process. Building modules are installed piece by piece in a repetitive manner and set in place either by dry stacking or mortared together. A dry stacked assembly does not use mortar and relies on gravity to compress stacked modules into a monolithic assembly. Te mason carefully selects the shape and form of stones to prevent the stone from slipping in the construction. Typically, the stones are similar in size and scale and an intermittent large stone spans the width of the wall to tie together the assembly. A mortared assembly uses a mix of Portland cement, hydrated lime, water, and inert aggregates such as sand to bind modules together. Mortar should adhere to the vertical and horizontal surfaces of a module, but also the mortar needs to be workable and easy to spread. Mortar bonds between masonry units so the entire assembly functions as a mono­ lithic assembly. It creates a seal to keep water and wind out of the stacked assembly. Te mor­ tar profle is also designed to shed water. Te profle impacts the aesthetic appearance and texture of the assembly surface. Stacked assemblies are also not limited to walls. Stacked roof structures are possi­ ble when bricks are stacked to create arches that span openings. Catalan vaults are constructed using thin veneers of bricks stacked in a multi-layered lamination. Wood scafolding, also known as centering, is used as a formwork for laying and mortaring bricks into a low arch. Once the mortar sets, the formwork is removed and the assembly is essentially a monolith. If a fast-setting mortar is used, then a wood formwork may not be needed. Te key to stacking is for the modules to bear weight on each other so the structural forces are carried down to the foundation.

Historical Shift from Bearing Wall to Veneer Cladding Troughout history, stacked materials systems were the most common construction method. Te assembly refected characteristics of stability and durability while still maintaining a con­ nection to the human scale. Brick is generally considered an industrial and economical material. Stone and brick are typical modules used in buildings for its monumentality and durability. In contemporary construction, the role of stacking building materials has shifted. Historically, it was more common that a stacked assembly was a load-bearing structure. In modern times, due to cost efciencies, economy of materials, and advancements in other building technologies, stacked brick and stone are increasingly relieved of structural duties and they are more com­ monly used as veneer or cladding materials. In many historical buildings, brick would be used as the exterior and the inte­ rior surface in a wall assembly. Te mass of the stacked modules and an air gap between the outer and inner wall would provide thermal insulation. In contemporary construction, the outside face and the inside face of a wall are not necessarily the same materials. Stacked materials used as veneer cladding reduce the amount of material while still appearing like a

191

Why Stack?

masonry wall. Aspects of cost, thermal requirements, and new construction materials and methods determine whether we actually stack materials. On the surface, the wall looks the same whether it is a structural stacked assembly or a cladded assembly. Since the stacked assembly does not need to take on structural responsibilities, the primary reasons for choos­ ing a stacked assembly shifts to the aesthetic characteristics of stacking modules.

192

4.3

What Happens When Stacking?

What Are the Failures/Limitations/ Problems We May Encounter? When working with stacking modules, we cannot let issues of costs and efciency in construc­ tion dictate the potential of the assembly design. Tin veneers used to simulate the appear­ ance of load-bearing masonry walls may now be a commonplace construction strategy, but it removes the responsibility and integrity of the building module. Te module no longer has to bear weight and the stacking pattern does not have to help transfer the weight of the assembly. What we fnd most exciting about stacking is that a strategic aggregation and arrangement of small modules will produce a monolithic weight-bearing structure. All the stacked units work together, with the help of additional supporting materials, to produce an enclosure. In thinking about stacking materials, questions regarding lateral stability, height limitations, texture, porosity, and weight emerge for us. Tese issues impact design decisions and challenge us to reimagine stacked assemblies. Brick is often treated like a common and standard building material that then lacks a presence. However, valuing the module and investing in its potential has produced innovative strategies in stacking.

STUDENT EXPERIMENT How Else Can We Integrate a Stacked Assembly with Another Material System? Anggita Zurman-Nasution | University of Florida In this full-scale construction, Anggita tested an atypical method of reinforcing and structurally supporting a stacked assembly without using a back-up wall and mortar. In most stacked constructions, steel reinforcing may be hidden within the wall assembly to support and align the assembly. Anggita initially proposed a steel box framework that would have an equal presence with modules in the assembly.

193

Why Stack?

Stacking masonry modules without mortar: Te steel framework would be integrated with the stacking modules to produce open space between each adjacent module. Te metal box frame would turn the assembly into a screen wall. Te steel would weave together the modules in the stacked assembly (Figure  4.27). Each masonry module would lock into the structural framework, so no mortar was needed. Te gap between each module would allow light to penetrate through and each masonry module would appear to foat in the assembly. Te steel structure would support the weight of each module instead of the modules bearing weight on the modules below. Addressing inconsistencies in the module: Anggita cast concrete modules with a wood formwork and holes in the modules would receive threaded steel rods. Te formwork

FIGURE 4.27

194

Original stacked assembly proposal. Photo: Anggita Zurman Nasution.

What Happens When Stacking?

was made of wood because it is a manageable material by hand, but using wood pro­ duced numerous issues. Te wood formwork would swell from the concrete mix and produced inconsistencies in the shape of the module. Te wood dowel used to cast holes in the modules was difcult to remove after it absorbed water in the concrete. Te module’s shape was intentionally angled so that a staggered bond pattern would emphasize the appearance of a woven assembly and the three-dimensional surface would cast shadows similar to the brick at the New Vic Teater. Negotiating two material systems: Due to limited resources, the steel box framework could not be welded and it was altered to a mechanically fastened framework. Te original project concepts were simplifed and key concepts were revised to maintain the idea of a metal framework that would allow in light and air between each mod­ ule. Te steel box frame was reduced to threaded rods. Te dimension of the holes cast into the module was exactly the size of the threaded rod, so it did not account for inconsistencies and unevenness in the module. Trying to insert the threaded rods then made the module more prone to breaking. (Figure  4.28) It was too difcult to achieve precision between each module because of the irregular geometry of the concrete module. Nuts were used as spacers to create the gaps between each module. However, this made the assembly sequence more complex because the modules had to be individually adjusted to be level. It was a challenge for Anggita to thread and level each module with uneven surfaces and misaligned holes in the module. Te steel reinforcing system required too much labor to adjust each module and the assembly swayed since the vertical steel rods had no lateral support. Ultimately these factors limit the height of the assembly

FIGURE 4.28

Attempt at assembly. Photo: Lisa Huang.

195

Why Stack?

Lateral Stability and Height: How Do We Increase the Height of an Assembly of Small Modules While Keeping It from Overturning? In the stacked assembly, each module bears weight on each other for structural strength, but a primary concern when stacking is lateral stability. Gravity plays a role, but as the assembly increases in height, the arrangement of small modules becomes more susceptible to horizon­ tal forces. Stacked modules, on their own, have height limitations as a structural assembly. Veneer cladding is an alternative strategy to maintain the look of a stacked assembly in tall structures. Increasing a stacked assembly’s height requires changes in formal geometry or the use of additional material systems that help absorb structural loads. Historically, the tallest masonry load-bearing skyscraper is the Monadnock Building by Burnham & Root in Chicago. Te Monadnock Building, built in 1891, is six­ teen stories high and 215 feet in height (Figure 4.29). In order to achieve this height, the

FIGURE 4.29 Photo: Cervin Robinson, Monadnock Building in Chicago, Library of Congress, Prints and Photographs Division, Survey HABS IL-1027, Call number HABS ILL,16-CHIG,88-.

196

What Happens When Stacking?

FIGURE 4.30 Monadnock longitudinal sec­ tion drawing with dimension changes in load-bearing masonry walls. Historic American Building Survey, Photocopy of Measured Drawing by Dieter Sengler, 1964, Library of Congress, Prints and Photographs Division, Survey HABS IL-1027, Call number HABS ILL,16-CHIG,88-.

stacked brick wall’s thickness at the top of the building was 12 inches and at the base of the building, the masonry assembly was six feet thick. Te wider base provided a solid founda­ tion and lateral stability to prevent the masonry walls from overturning. Since each module bears weight on the modules below, the structure carried the most weight at the bottom of the building. Te masonry assembly narrowed in width as the structure increased in height to reduce weight (Figure 4.30). Each brick module was bound together using mortar, but any weakness or deterioration in the joints between mortar and brick added vulnerability to the assembly. Te Monadnock walls use width and mass at the bottom, creating redundancy in the structure, in order to push the building to higher heights. During this point of time, steel was economical and common in tall building construction, so other masonry structural buildings did not try challenging the height of Monadnock. Stacking modules requires some reinforcement to strengthen the assembly. Te reinforcing structure for masonry construction is typically invisible—hidden with the wall assembly. Masonry modules are strong in compression, but steel reinforcing is needed to

197

Why Stack?

make up for structural weaknesses. Steel reinforcing bars are either set into mortar between masonry courses or grouted in between two masonry wythes. Te mortar holds the reinforc­ ing components in place and integrates the reinforcement into the assembly. Tis provides vertical and lateral support between modules. Vertical reinforcement in a CMU assembly is often set within the hollow cells of CMU modules. In a typical brick cladding installation, the stacked masonry assembly is fastened with tiebacks to the back-up wall. Te steel rein­ forcing structure is a secondary system. It does not provide enough structure to extend the height of a masonry assembly. It provides additional structural stability to the assembly, but it does not assist the stacked masonry in bearing weight. As an alternative to widening the base of the masonry wall, a stacked assembly could be reinforced by a supporting framework that helps to resist any lateral instability. Kengo Kuma’s Chokkura Plaza is only one-story tall but it uses a steel framework to support stone modules that foat within the stacked assembly (Figure 4.31). Te building is an addi­ tion that abuts and aligns with a former rice warehouse. To integrate the existing building and new building, Kuma uses matching Oya stone and the dimensions from the existing structure. Oya is a porous and soft stone which was also used as a veneer facing in Frank Lloyd Wright’s Imperial Hotel. At the junction between the existing warehouse and Kuma’s addition, the spacing between the stone rows gradually transitions from conventional opaque masonry wall to appear as an expanding screen masonry assembly (Figure 4.32). Each stone module is cut in a ‘V’ shape and the stacking pattern produces apertures and textured light and shadow within the addition. At the Chokkura Plaza addition, the stacked assembly has a welded steel plate framework that holds each stone module. Te fat steel plates fold to support the underside of the stone modules. Te stone block is notched on its inner edge to receive the steel framework. Te steel plate is only visible on the bottom edge of stone and when the wall assembly turns

FIGURE 4.31 Stacked stone façade at Chokkura Plaza. Photo: courtesy of Kengo Kuma Associates.

198

What Happens When Stacking?

FIGURE 4.32 Stone modules transitioning from opaque to screen. Photo: courtesy of Kengo Kuma Associates.

FIGURE 4.33 Steel frame sup­ porting the stone modules. Photo: courtesy of Kengo Kuma Associates.

a corner (Figure 4.33). At the corners of the building, Kuma reveals a vertical steel plate of the framework. Te stone blocks at the corners are mitered. Te sharp corners of the stone would be vulnerable to breaking, but the steel plate helps protect the stone. When two peaks of folded plates touch, a vertical steel plate connects between each horizontal plate function­ ing like a steel beam. Tis creates a rigid steel frame that takes care of lateral stability for the

199

Why Stack?

entire wall assembly. Tere is no steel reinforcing threaded into each module. Te folded steel frame is a shelf structure for the stone blocks. Each soft Oya stone at the Chokkura Plaza does not directly bear any weight on adjacent stone modules. Te stone block’s weight transfers to the steel structure. so, the stacked soft stone is not limited by its bearing capacity and the wall assembly could extend in height. Standard reinforcing steel in stacked assemblies holds the wall back and maintains alignment in the assembly. Kuma sets the edge of the steel frame one-half-inch from the face of the stone. Te dark-colored steel frame is recessed in shadows of the assembly, allowing stone to be the primary material in the stacked assembly. When we look closely at the detail, the reveal between the rows of stone modules and the horizontal folded plate is visible. Te interstitial steel plate connection is hidden so that the stone looks like a continuous row of masonry. Tis allows the space between each row to be an uninterrupted opening. Te Chokkura Plaza addition references the monolithic nature of masonry, but creates a stacked stone assembly that appears extremely light.

Lateral Stability and Height: How Do We Make a Fluid Form Out of Something Rigid? Without the use of a substantial steel reinforcing structure, we can also achieve structural stability in a masonry assembly by changing the geometry and form of the assembly. Te serpentine garden walls on the University of Virginia campus are historical examples of form providing structure in a masonry assembly. Interestingly, the serpentine wall was not driven by aesthetics but rather by efciency and stability. Tomas Jeferson fgured out an economi­ cal way to build these low garden walls by deviating from the straight line. A typical straight masonry wall would require a reinforced double wythe assembly for stability. With English low wall constructions as precedence, Jeferson recognized that a single wythe of brick laid out in a sinuous line would use less bricks and was structurally stable without adding rein­ forcement to the assembly (Figure  4.34). Te height of the wall is limited without lateral

FIGURE 4.34 University of Virginia ser­ pentine garden walls. Library of Congress, Prints and Photographs Division, HABS VA-193-D.

200

What Happens When Stacking?

support, but the undulating form has an inherent stability that prevents the wall from top­ pling over. In a more contemporary example, Gramazio Kohler and the Swiss Federal Institute of Technology in Zurich (ETHZ) further studied the potential of the serpentine stacked wall and form in the Structural Oscillations installation. Working with digital fabrication tech­ nology and equipment, Gramazio Kohler and their students experimented with the use of a robotic arm in the construction process to achieve a higher level of precision and complexity in the single wythe serpentine wall (Figure 4.35). Teir research tested the automated process of constructing a dynamic stacked assembly. Another aspect of their research was the development and application of an adhe­ sive instead of traditional mortar, thus minimizing the spacing between bricks. Te robotic arm was also programmed to administer the binding material. Te undulating form created a complex interface between two bricks—an issue we discussed in the Archi-Union Ofce and Exhibition Space project. Once we change the geometry of the stacked assembly, every overlap between bricks is diferent. Advances in digital technology allowed the possibility of precisely programming the application of the adhesive or mortar. Otherwise, the manual labor in applying mortar precisely is a time-consuming efort. Te Structural Oscillations installation achieved a more complex geometric form than Jeferson’s serpentine walls. If each module is small in dimension, the stacking orientation and pattern easily accommodates vari­ ation in the surface plane. However, inherent in the stacking process, the overall pattern of the assembly relies on an organization of horizontal bands of modules. Tese horizontal strata are always present in a stacked assembly. Te work of Eladio Dieste in Uruguay during the mid-20th century challenged the formal potential of stacked structures that were geometrically complex in both vertical and horizontal surfaces and their meeting points. Te Church of Christ the Worker in Atlantida and the San Pedro Church in Duranzo are examples of stacking small modules appearing to

FIGURE 4.35 Gramazio Kohler Structural Oscillations. Photo: Gramazio Kohler Research, ETH Zurich [CC BY-SA 4.0 (https://c reativecommons. org/licenses/by -sa/4.0)].

201

Why Stack?

defy the laws of gravity. Universally, brick is often seen as a common and mundane building material. Brick was considered industrial and inexpensive in Uruguay, so Dieste dedicated his work to showcasing refnement and innovation in stacked brick assemblies and establishing a new appreciation of the material. Dieste used curved masonry forms to achieve greater height and lateral stability while also creating compelling building forms. He pushed the structural possibilities of brick to demonstrate beauty in common materials. In the walls and roof of Church of Christ the Worker, Dieste used undulating forms for structural stability and for transferring weight between the horizontal and vertical planes (Figure 4.36). Te base of the church’s sidewalls start as a straight line, then the verti­ cal plane starts to undulate. Each brick in the wall is ofset from the row of bricks below as the wall transitions to a serpentine form at its top edge (Figure 4.37). Dieste brings light into the church through multicolored stained-glass inserts pixelated within the undulating brick walls. Like Jeferson’s serpentine garden walls, the principles of the church’s construction rely

FIGURE 4.36 Entrance façade to the Church of Christ the Worker. Photo: Julian Palacio.

FIGURE 4.37 Ruled surface of the brick walls. Photo: Julian Palacio.

202

What Happens When Stacking?

on geometric form to reduce the need for additional structural reinforcing and to make an efcient and economical structure. Unlike the garden walls, the church’s walls are a double wythe masonry assembly to increase the building height. Te serpentine walls at Church of Christ the Worker work together with an undu­ lating roof to establish the building’s structure. Te roof is essentially a series of catenary arches that distribute its weight in compression and transfers it to the walls (Figure 4.38). Dieste, an engineer, pushed structural possibilities with the vault’s geometry and the thin­ ness of the roof as a masonry assembly. Te roof is constructed with veneer bricks stacked in staggered layers. A steel framework is set into the mortar, between brick modules, to bind the brick veneer layers and provide tensile strength in the roof assembly. Te roof’s brick veneers bind together to become a single unifed assembly. Te intersection between the sidewalls and the roof not only gradually transition between vertical and horizontal assemblies but it is also a highly engineered joint.1 Te thinness of the roof is expressed in the eaves cantilevering past the walls. Te extension of the roof edge not only draws water away from the wall’s sur­ face but also distinguishes the vertical and horizontal planes into two diferent components. Incredibly, the brick assembly conveys thinness and lightness and defes expectations for a masonry assembly. Dieste reinforces this idea of lightness on the interior. Te brick wall that defnes the space of the altar, sacristy, and chapel does not touch the roof or walls. At the entry of the Church of Christ the Worker, the thinness of the roof and walls align to create a frame for the recessed entrance façade. To articulate the main entrance, Dieste stacked brick in a single wythe curving inward to create the appearance of a carved entry into the church. Te brick screen above the entrance further explored the innovative possibilities and the structural limits of brick. Dieste stacked brick veneers in a single layer to create delicate masonry panels that seem impossibly thin (Figure 4.39). Each panel is set at an angle to allow light into the church and the angle changes for each row of masonry panels to vary the light quality entering the church. Supporting each row of brick panels, Dieste used the same thin brick veneer laid horizontally to create a continuous thin plane defning each

FIGURE 4.38 Interior of the Church of Christ the Worker with undulating roof. Photo: Julian Palacio.

203

Why Stack?

FIGURE 4.39 Thin stacked veneer screen at church entry. Photo: Julian Palacio.

row of panels. Tis screen is set into the overall structure so that it only needs to support its own weight Dieste emphasizes this façade screen as a foating stacked assembly using a contin­ uous reveal that makes a physical separation between undulating building enclosure and the façade screen. Te reveal and building frame create the illusion that the stacked brick screen is lightly held within the façade. Te entire screen defes gravity at the scale of the building façade, the thin screen assembly, and the brick veneer module itself. Inside the church, the light from the façade screen grazes across the brick veneer and celebrates the textures in the brick assembly. Troughout his work, Dieste tests the structural and expressive potential of brick that defes the brick’s standard characteristics. In the San Pedro Church, the rosette window is an astounding structural feat. Te rosette is composed of fve brick diaphragms in the shape of an irregular hexagon (Figure 4.40). Each diaphragm is made of two-inch-thick brick veneers similar to the stacked brick screen in the Church of Christ the Worker. Te rosette is supported on thin steel frames that create the illusion of brick foating in light. Dieste

204

What Happens When Stacking?

FIGURE 4.40 Rose window at the San Pedro Church. Photo: Julian Palacio.

challenged conventional expectations of brick and experiments with new ways to think about stability and structure in a stacked assembly. Brick is a common building material that has a simple construction, but Dieste highlighted the impact that the form of the assembly has on structure and height limits while also bringing delight to the material and assembly.

Pattern and Texture: How Can We Use the Individual Module to Contribute to a Dynamic Collective for the Uniform Monolith? In a stacked assembly, each individual module contributes to the larger whole. Materials like brick and stone naturally have inconsistencies in color or texture, but once they are set into a monolithic surface, their individuality blends together, like pixels that compose the larger digital image. We have to look closely to see the diferences in each individual module. Te size, orientation, and patterning of stacking components dictate the form of the assembly and the overall composition and appearance of the building. A module like brick is rigid in its individual form, but the arrangement of stacked modules can create surface textures with three-dimensionality and variety in the monolithic assembly. Trough two projects by Alvar Aalto, we will look at two methods of manipulat­ ing the stacked module to create texture – customizing the module itself and varying the ori­ entation of a standard module. Aalto experimented with red brick on numerous projects as we discussed regarding the clinker bricks for the MIT Baker House. Aalto implemented various strategies to explore the potentials of stacking brick. Aalto’s House of Culture reconfgures the shape of the individual module to mirror the larger form of the building. In modifying the brick module, he applies his design intentions at multiple scales of the project. Each cus­ tom brick is an isosceles trapezoid in plan and oriented so the widened part of the trapezoid is the exterior face of the brick. Te brick’s shape and its rounded exterior corners correlate with the fan-shaped foor plan of the building.

205

Why Stack?

Te narrow part of the brick module, which would be hidden within the wall assembly, is not curved. Te profle of the mortar is set back to allow the rounded vertical edges of each brick module to be more pronounced. Te bricks are laid in a ‘stacked’ bond pattern where the bricks do not stagger but instead align one on top of the other. Te vertical alignment of bricks also aligns the curved vertical edges of the brick. Tese rounded module edges produce the illusion of a square proportion for brick face and downplay the vertical alignment of the rounded brick edges. From a distance, the building’s brick façade appears uniform and consequently emphasizes the curved corners of the building. Even with the custom brick shape, the stacked modules aggregate into a monolithic construction and the individual brick disappears into the larger assembly. But in the House of Culture, the brick’s unique form has a reciprocal relationship with the building’s overall form. Te patterning of modules in a stacked assembly has a huge impact on the texture of the assembly. Te standard brick module is dimensioned and proportioned so that the six brick faces can all participate in stacking patterns. In the Experimental House in Muuratsalo, Aalto used the façade of his summer studio and house as a palette to test numerous ways of patterning bricks. Te façade is a collage of diferent brick types, colors, orientations, and patterns (Figure 4.41). Changing the orientation, pattern, and spatial relationship of modules produced shadow and texture variation in the stacked assembly. In the façade, Aalto used diferent sizes and proportions of brick. Te staggering or overlapping of bricks help to tie bricks in both vertical and horizontal directions of the assembly. As we can see in Aalto’s Experimental House, altering the position of the module from the face of the main assembly produced textures and shadows in the stacked pattern. We can also see three-dimensionality from the tooling of the mortar. Te profle and recessed depth of the mortar to the face of the brick helped to highlight the individual module. Te spacing between bricks and mortar thickness produces a visible infrastructure that weaves together the stacked modules (Figure 4.42).

FIGURE 4.41 Stacked facade of Aalto’s studio and house. Photo: Jonathan Reinke.

206

What Happens When Stacking?

FIGURE 4.42 Detail of the differ­ ent brick patterns. Photo: Zachary Wignall.

Te main issue we need to consider when modifying a module’s shape or when shifting the overlap between modules is that the application of mortar will be more difcult. If there are ledges between modules, then tooling the mortar joint is a less efcient process in the construction. Also, any ledges made between modules create a place for water and dirt to sit at the mortar joint. Water penetration can ultimately degrade mortar and damage the assembly over time. Cutting bricks to the required sizes is done out of convenience to ft the building design. It would take great efort to design the entire building based on a small brick module. In the Experimental House façade, the mortar dimensions are standardized dimensions in each stacked pattern. Along the roof eave, bricks that encountered the slanted roof edge stag­ ger so that the metal fascia overlaps the brick edge hiding any irregular gaps. In the St. Petri Church, Sigurd Lewerentz designed the entire complex using a four-inch (100mm) brick module. Te overall building dimensions were coordinated with brick module dimensions which was an innovative approach in the mid-20th century. Lewerentz imposed the design parameter that no brick would be cut in the construction.2 But a smaller 3.15-inch (80mm) brick was delivered to the construction site, so the masonry patterns were adjusted by varying

207

Why Stack?

the mortar thickness instead. As a result, the mortar patterns are fgural adding another dimension to the texture of the masonry (Figure 4.43). Te St. Petri Church complex consists of two buildings, a rectangular main church, and an L-shaped auxiliary building, that form a courtyard. Lewerentz was compre­ hensive in working with brick masonry at St. Petri’s—the walls, foor, roof, and the altar are entirely constructed out of stacked bricks. Lewerentz intended that no brick would be cut during construction; however, it was not always possible.3 But with this guiding parameter, he challenged the standards for brick masonry construction and the fgures produced from varying dimensions of mortar joints alter the typical appearance of a masonry assembly. If the building form is set in dimension and a specifc brick module is used, there is a potential dimensional discrepancy if the brick module spacing and the standard threeeighths of an inch mortar thickness are not coordinated in the overall building. In St. Petri Church, the mortar mediated dimensional diferences in the assembly. In typical stacked assemblies, the uniform thickness of applied mortar has less of a visual presence; it plays a supporting role in the masonry assembly. Lewerentz uses diferent brick patterns through­ out the complex as a strategy for designating diferences in the church complex’s programs.

FIGURE 4.43 Mortar joints as fgures in Lewerentz’s St Petri Church. Photo: Zachary Wignall.

208

What Happens When Stacking?

Troughout the church complex, the mortar joints highlighted spatial conditions and medi­ ated between diferent stacking patterns. Te roof of the church structure is a steel frame with series of brick vaults that pro­ ject a scalloped edge on the public entry façade of the building. At the intersection of the roof and the walls, Lewerentz negotiated between curvilinear building forms and the orthogonal form of the brick. Te full-sized bricks stop where needed in relation to the vaults and then mortar flled in the space between the two geometries. Lewerentz did not alter the brick mod­ ule for the building form. Instead, he let the stacking patterns determine the texture of the façade.4 Tis acknowledged that a monolithic construction is not necessarily monotonous in appearance. Te brick patterns set up a texture, but the mortar also has a dynamic presence in the assembly. Te idea of letting the mortar negotiate geometries was reinforced at other scales in the project. Te masonry walls in St. Petri Church are load-bearing and in the long span orientation of the church, steel beams span the width of the space and support the arches in the roof plane. Four light cannons on the east side of the church are fush with the façade but extend in height to accommodate a vertical skylight capturing southern light. Tese light cannons use two brick patterns – a running bond and a stacked bond. Te actual form of each cannon is the same, but the change of pattern creates the illusion of a variation in threedimensional form (Figure 4.44). Te patterning of the brick foor changes with the diferent zones of programmed activity within the church. At the christening font, the brick foor rises up in elevation to cre­ ate a mound that abuts against a slotted opening in the foor. A light metal frame holding the christening basin hovers above the foor opening. Lewerentz cantilevered bricks at the ends of the foor opening thus challenging the limits of individual bricks to defy gravity. In front of the christening font, the brick foor changes to a grid pattern and the mortar is recessed creating the shadow of a cross on the foor at the location where the priest stands during the ceremonies. Even the locations for the congregation chairs are marked with the pattern of

FIGURE 4.44 The four light can­ nons with alternat­ ing brick patterns. Photo: Trevor Patt.

209

Why Stack?

the bricks and mortar. Te bricks under the chairs organize along mortar joints that deviate from the adjacent brick pattern; thus, highlighting these bands as fgural moments. A thick mortar band was inlaid to locate and align the back end of the chairs (Figure 4.45). Other furniture and the altar are also constructed with stacked brick that is contiguous with the brick assembly. Te bricks pattern in the foor is laid on end to designate the zone of the altar. Doors and windows in St. Petri Church are not set within brick openings. Doors either overlap the exterior façade or the brick façade is recessed and the door is layered onto the interior face of the wall. Te windows are glass panes overlaid on the exterior face of the brick assembly (Figure 4.46). Te glass panes are held by clips fastened to the brick and then

FIGURE 4.45 Brick pattern designating chair locations. Photo: Zachary Wignall.

FIGURE 4.46 Window detail at St Petri Church. Photo: Zachary Wignall.

210

What Happens When Stacking?

sealed at its seam for weatherproofng. Te arrangement of brick and mortar had to accom­ modate the overall building form, but their arrangement superseded other building compo­ nents like thresholds and apertures. From within interior spaces of the complex, there are no visible window frames for the glass, so the form of the stacked assembly is uninterrupted. Lewerentz demonstrated that both the module and the mortar can contribute character and texture in a masonry building. Rules and parameters established for stacked patterns help create textural efects that afect not only physical characteristics but also the perception of space. In the Aalto’s House of Culture, the brick shape was fgural to refect the trap­ ezoidal building form. In St. Petri Church, the patterning of brick and the spacing of mortar took on fgural forms. In both these projects, stacked modules were adjusted to ft the overall building form. Te positioning of each brick module can also infuence the shape of the three-dimensional building form. In Ofce dA’s Tongxian Gatehouse, the composition of stacked brick modules creates texture and shadow on the surface of the building while the brick patterning also establishes the building’s fgural form. In the Tongxian Gatehouse, the brick assembly is not a load-bearing structure. Te masonry is the exterior cladding on a concrete structure and the building showcases the skills of local masons. In exterior appearance, the building is a brick monolith inserted with wood apertures. Te brickwork subtly plays with the position of the brick to create transitional changes in the building’s surface texture (Figure 4.47). Te brick stacking pat­ tern is not just about interacting with light on the façade. Te brick spacing compresses and expands, both perpendicular and parallel to the façade plane, to ultimately shape the building’s form. Tere is a resonance between form-making at the scale of the module and at the scale of the overall building. On one end of the Gatehouse, the second foor of the building cantilevers to frame an entry into the site. A layer of bricks is clad to the underside of the cantilever to reinforce that the building is a brick monolith, but the brick stops short of the building corners to reveal the concrete structure. Te monolithic building exposes the brick as a cladding when the building extends over the road and the individual bricks on the façade react to this cantilevering action (Figure 4.48). Each header brick in the Flemish bond pattern also cantilevers from the surface of the façade. To emphasize the texture of the brick pattern, the stacked brick is fush at the wood window and then turns the corner. Te protruding header bricks also turn the corner, but here, the bricks incrementally transition back to a fushed stacked surface. At the base of the building, a brick-clad plinth leads to a main entry that is recessed into the building form. Te operation of receding in the building form is also carried to the scale of the module. Te cladding of the platform is expressed with header bricks that set back from the façade surface. Te recessed bricks create a horizontal band that wraps around the building plinth. Tere is an inversion of shadow and texture between the recessed header bricks at the building base and the protruding header bricks on the cantilevered upper foors. Tis inversion is reiterated by protruding header bricks at the spatial joint between the build­ ing platform and the main entry (Figure 4.49). At the other end of the Tongxian Gatehouse, the building form bends in at the top corner. Te stacked bricks compress the wall assembly to narrow the form of the overall build­ ing. Te brick pattern reveals that the folding of the monolithic wall is associated with each

211

Why Stack?

FIGURE 4.47 Curved wall detail at Tongxian Gatehouse. Photo: Dan Bibb, courtesy of NADAAA.

brick incrementally shifting laterally at the corner (Figure 4.50). Te stretcher bricks along this edge remain fush with the façade, but the header bricks set back. Te spacing between the stretcher bricks closes in toward the top of the building. Te wood windows interrupt the façade, but the bricks continue to set back as a single veneer layer. At every corner, the build­ ing reveals that the brick is a cladding. Te brick façade is a veneer, but it directly infuences the building geometry. Te stacking pattern and texture of the bricks celebrate a resonance between the individual module and the overall building form. So far in this section, we have looked at projects where standard brick faces are always parallel with building façade. Stacking patterns of standard modules that are not at a 19 orthogonal to the façade plane can also impact the building form and play with light and shadow in new ways. Te bricks in Dean Wolf Architects’s Hyderabad housing project shift in and out in a pattern that determines the concrete structure and the form of the building façade. Like the Tongxian Gatehouse, this building also takes advantage of skilled masonry construc­ tion traditions in India. It is important for us to acknowledge and work with local skills and

212

What Happens When Stacking?

FIGURE 4.48 Building cantile­ vering over the road. Photo: Dan Bibb, courtesy of NADAAA.

FIGURE 4.49 Main entry into the Tongxian Gatehouse. Photo: Dan Bibb, courtesy of NADAAA.

213

Why Stack?

FIGURE 4.50 Brick pattern turn­ ing the building corner. Photo: Dan Bibb, courtesy of NADAAA.

techniques in order to achieve precision in building assembly. In this Hyderabad housing project, the bricks in each row zigzag and each row of bricks shifts laterally resulting in a diagonal pattern on the surface of the brick façade. Te zigzagged positioning of each brick is in turn reinforced with a zigzagged concrete foor edge at the façade and the three-dimen­ sional zigzagged form of the concrete balcony. Te pattern of the standard brick modules creates a V-shaped reveal. Te shadow created is a small-scale version of the shadow cast by the concrete foor edge. For the South Asian Human Rights Documentation Center, Anagram Architects rotates a standard brick size to produce a dynamic fgural façade that functions also as a thermal barrier (Figure 4.51). Te façade wall’s thickness uses the length of the brick module. Te brick pattern scales up the module by using a six-brick unit. Tis composition of six bricks – three headers on top of stretcher bricks – sets up a module in the stacking pattern. On the opaque face of the wall, every three bricks in a double course rotate nine degrees creating complex texture on the facade surface. Te vertical mortar joint is continuous. Tere is no shifting in the mortar joint. Te bricks rotate for eight courses and then are fush to provide stability in the stacked assembly. Te rotation of the bricks produces varied geometric surface geometry in the oblique views of the façade (Figure 4.52). Te rotation of individual bricks and of the six-brick unit adds three-dimensional form to multiple scales of the build­ ing façade. Te twisting bricks in the sculpted assembly also allow light and air through the façade. In the porous part of wall, a single wythe of bricks makes a quarter turn every two courses in order to create openings in the façade. Te brick façade is monolithic. but the organization and arrangement of stacked modules adds depth and dynamic surface texture that plays with light and shadow. Tis innovative and complex patterning of bricks challenges the uniform masonry assemblies to imply movement in the facade surface.

214

What Happens When Stacking?

FIGURE 4.51 Dynamic facade of the South Asian Human Rights Documentation Center. Photo: courtesy of Anagram Architects.

215

Why Stack?

FIGURE 4.52 Oblique view emphasizing movement in the surface. Photo: courtesy of Anagram Architects.

STUDENT EXPERIMENT How Else Can We Transmit Light Trough a Monolithic and Opaque Assembly? Ali Atabey | University of Florida In this study, Ali was interested in a brick screen alternative that asks what if mortar was replaced with a light transmitting material. Usually in brick assemblies, brick modules are removed or shifted to produce a screen. Ali was interested in using the space between bricks as the aperture for transmitting light through the stacked assembly. Ali used onehalf-inch-thick acrylic sheets to test a strategy for transmitting light through a solid masonry wall (Figure 4.53). Holding together a stacked assembly without mortar: Te brick modules were dry stacked in Ali’s study, so he immediately had to confront the issue of what will bind together a stacked assembly if a non-adhesive material replaces mortar. Mortar was not going to bind the acrylic to the bricks. But without an adhesive, the stacked assembly was loose and unstable. Using hollow core bricks, Ali applied mortar and reinforcing steel bars within the brick cores to stabilize the assembly. Te mortar secures the steel system within each brick which then in turn secures the assembly. Te mortar is hidden from the brick surface and the reinforcement structure is inter­ nalized. Ali then laser cut holes into the acrylic sheets to match the hollow cores in the brick module. Te frosted edges of the acrylic worked perfectly to obscure the reinforcing bars within the assembly, but aligning each brick and the steel reinforcing was not reliable. Filling each hole with mortar was signifcantly more laborious than the application of mortar in typical masonry constructions. Injecting mortar into

216

What Happens When Stacking?

FIGURE 4.53

Drawing of the stacking proposal. Photo: Ali Atabey.

brick core holes was also difcult because the position of hollow cores is not identical in each brick (Figure 4.54). Creating a complex form: Because of slight inconsistencies in each brick module, Ali developed a pattern of formally shifting modules to make up for misalignments inev­ itable in the assembly. Te pliability of mortar in typical masonry assemblies easily negotiates material inconsistencies in brick modules. A dimensional stable acrylic sheet against brick however, highlighted the discrepancies in the modules. Varying the profle

217

Why Stack?

FIGURE 4.54

Tests to bind the stacked bricks. Photo: Ali Atabey.

of the acrylic sheets tested the geometric formal patterning of the stacked assembly, the ability to hide discrepancies, and the creation of unique shadows on the three-dimen­ sional surface of the assembly. Ali laser etched a template for locating each brick module into the surface of the acrylic. Acrylic sheets have a size limitation, so there would be a joint abutting each sheet. In this study, acrylic was only tested as a horizontal element. Since the reinforcing structure does not extend horizontally, vertical acrylic compo­ nents would need to be interlocked to the horizontal acrylic components. Casting light through the gaps of the stacked assembly: Te frosted acrylic produced interesting shadows transmitting light through the brick assembly (Figure  4.55). Casting light through the brick wall is most efective as a single wythe construction that is not concerned with water penetration and thermal insulation. Acrylic stacked with brick modules will not produce a watertight assembly, so water can gather on the ledges. In thinking about the application of this stacking assembly, the project provoked additional questions about the UV discoloration of translucent materials, the efects of trapped water on the steel reinforcing system, and height limitations for the assembly.

218

What Happens When Stacking?

FIGURE 4.55

Final stacked assembly. Photo: Ali Atabey.

Porosity and Lightness: How Do We Transmit Light through a Stacked Assembly? Te façade of MVRDV’s Crystal Houses in Amsterdam regulates light by using glass blocks as a light-transmitting load-bearing wall. Te solid glass blocks are stacked on top of each other like a conventional masonry wall. Te Crystal Houses facade is completely transpar­ ent at the ground level and then gradually transitions into an opaque terracotta masonry structure. Te glass blocks are cast in the identical form and dimensions of the terracotta brick in order to produce a fush façade. Researchers from Delft University of Technology (TU Delft) worked in partnership with MVRDV to develop this stacked glass façade system. Trough their research and tests, they found that the stacked glass assembly is ten times stronger than a standard brick assembly. Instead of mortar, the bricks join together with a clear UV-curing adhesive. No reinforcing material like steel is needed. Te clear adhesive increases the strength of the stacked assembly. Like a brick masonry load-bearing structure, the glass bricks wall thickens and widens at the base, like buttresses supporting the weight of the façade. In the Crystal Houses, the entire stacked façade is transparent. When stacking, we can also incorporate conventional windows or module-sized openings to regulate light through the assembly. At the scale of the individual module, we can remove modules, selec­ tively omit mortar, or use translucent materials like glass blocks to produce screens that are both monolithic and lacy. Making a permeable screen relies on the arrangement and orienta­ tion of stacked modules. In this section, we will examine ‘lightness’ in terms of strategies to mediate natural light and air ventilation in the stacked assembly.

219

Why Stack?

Te permeable stacked assemblies that we commonly encounter will remove indi­ vidual modules or sliding bricks apart to create an opening. Te dimensions of the opening are a module within the stacking pattern. Studio Gang’s Brick Weave House uses a brick screen to provide privacy from the public sidewalk for its front courtyard. Te open-air screen is an assembly of a single brick wythe. Te bricks, in a running bond pattern, pull apart to allow the passage of natural light during the day and artifcial light outward at night. Each brick minimally touches the ends of the bricks below and above. In between each screen sec­ tion, a vertical band of solid bricks ties the façade back to structural steel posts (Figure 4.56). Te porosity and the thinness of the stacked brick create an elegant façade that both demate­ rializes the brick and establishes a uniform appearance. As an alternative to sliding modules apart, we can also rotate the individual mod­ ule to create openings. In Studiomake’s Dude Cigar Bar, individual bricks, set in a running bond pattern, rotate at incremental angles to create a porous and textured screen Figure 4.57).

FIGURE 4.56 Privacy screen at the Brick Weave House façade. Photo: Leslie Fiedler.

FIGURE 4.57 Rotated bricks in the interior wall of Dude Cigar Bar. Photo: courtesy of Studiomake.

220

What Happens When Stacking?

Tis interior wall is a single wythe of bricks that divides the entry vestibule and the main bar. Tis wall provides both privacy and connection between the bar’s spaces. Te bricks rotate in alternating rows of coursing and the angle of rotation engages the occupant and moderates the ability to see into the bar. Walking along that wall, the view, and perspective into the main bar changes while also cigar smoke would permeate as an introduction in the main bar space. (Figure 4.58). Te work of Laurie Baker in India demonstrates a wide variation of creating open­ ings in stacking patterns. Brick is a common and economical building material in India and the jali – a perforated screen – is a typical passive cooling strategy. Tis single wythe brick screen ventilates the space and also shields the harsh sun. Baker explored a range of compositions that rotated, removed, and separated brick modules to produce fgural openings in the brick assem­ bly (Figure 4.59). Te resulting shape of the screen openings is just as important as the brick module itself. Minimal contact between modules is sufcient in distributing weight in a stacked assembly, so the arrangement of bricks and openings has unlimited potential for façade patterns. Typically, if the stacked wall is permeable and lacy, it is accomplished with a sin­ gle wythe of masonry and it is left exposed to the weather. In the Kolumba Museum, Peter Zumthor integrates porosity into a double wythe masonry assembly. Te monolithic stone

FIGURE 4.58 View through the rotated brick screen. Photo: courtesy of Studiomake.

FIGURE 4.59 Details of Laurie Baker’s stacked brick structures. Photo: Ming Thompson.

221

Why Stack?

masonry enclosure becomes a perforated stone screen that protects and ventilates the space of the archaeological ruin (Figure 4.60). Te spacing of the modules on the inner and outer wythes match so that the aper­ tures align through the wall. As a result, when natural light enters the interior space, the light bounces of surfaces within the wall assembly so that a spectacular dappled light enters the space (Figure 4.61). Te horizontal gray modules, specifcally developed for the project, have

FIGURE 4.60 Stacked stone exterior of Kolumba Museum. Photo: Lisa Huang.

FIGURE 4.61 Light that trans­ mits through the stacked stone wall. Photo: Lisa Huang.

222

What Happens When Stacking?

proportions much thinner and longer than standard modules (20.7 inches × 4.25 inches × 1.33 inches) Te overall façade wall thickness is the same as the length of the stone module, so the stone is intermittently rotated to tie the two wythes together into one assembly. Tis stacking pattern contributes to the illusion of a random pattern of perforated modules in the façade. Steel tube columns are set between the two masonry layers and cast shadows through the assembly which contrast the natural light. At the Kolumba, the stacked stone modules are spaced apart to produce a per­ meable wall assembly. Rotating the stone structurally strengthens a stacked wall by tying the two wythes together. At the Swiss Sound Box Pavilion from the 2000 Hannover Expo, Zumthor stacks newly cut Douglas pine and larch lumber in alternating directions, a nod to the traditional methods for air-drying wood. Te open-air pavilion is a composition of these wood screen walls where square sections of lumber are stacked in a pattern that refects the weight load. At the bottom of the screen wall, the square wood members are stacked close together and then reduce in number above (Figure 4.62). Te lumber is com­ pressed together with steel tension cables spanning the top and bottom of the assembly to stabilize the construction. A series of buildings by Alireza Mashhadimirza reimagines the typical brick screen assembly through the lens of traditional Iranian weaving techniques. In all these housing pro­ jects, the mashiyaba inspired screen façade is porous ensuring privacy while also providing shading, air, and views. Mashhadimirza tests patterns variations in stacking single wythes of bricks with internal steel rods for alignment and structural support. Te inclusion of steel rods and plates into the stacked assembly produces fantastic and complex three-dimensional brick facades (Figure 4.63)

FIGURE 4.62 Stacked lumber creating parti­ tion walls for the Swiss Sound Box Pavilion. Photo: Roland Halbe.

223

Why Stack?

FIGURE 4.63 Brick wall pat­ tern at the Brick Pattern House. Photo: cour­ tesy of Alireza Mashhadimirza.

Mashhadimirza’s Brick Pattern House has a screen facade reminiscent of the stacking pattern at the Swiss Sound Box Pavilion (Figure 4.64). Te brick orientation rotates in alternating rows and as a result, it produces an opening in the screen. Te bricks are stacked in a bond pattern but then in every other brick coursing, a header protrudes from the brick wall. Bricks in various lengths cantilever of the facade to create a textured surface. Te shadows from the protruding bricks add depth to the façade. At a larger scale in the façade, the window apertures alternate on each foor and its form refect the confguration of the stacked brick units. Te project cleverly creates an intricate facade within a tight budget. Te con­ struction of the intricate brick pattern was essentially a puzzle, so Mashhadimirza devel­ oped an assembly system with coded bricks and an instructive diagram to simplify the installation. Te bricks stack on top of each other, but the stacked assembly is supported by steel rods threaded through the center of the aligned column of bricks (Figure 4.65). No mortar is used in the brick assembly. Te steel rods are hidden within the bricks and the span between steel lintels. Te steel rods connect the brick façade to the building structure and reinforce the appearance of a light masonry screen foating of the build­ ing. At the windows, stretcher bricks are removed to transform the brick assembly into a screen (Figure 4.66). Mashhadimirza plays with opacity and transparency to shield each apartment. In the House with Green Neighborhood, Mashhadimirza orients the bricks verti­ cally for the façade screen. (Figure 4.67). Up close, this creates an illusion of gravity defying bricks that slip past one another. Here, Mashhadimirza also drills into bricks and threads steel rods through each brick. In this assembly, the horizontal steel rods are interwoven with bricks and span between vertical steel plates hidden between the brick modules. Te bricks are stacked and mortared, so it prevents racking and sagging in the steel rod structure (Figure 4.68).

224

What Happens When Stacking?

FIGURE 4.64 Brick Pattern House textured façade. Photo: courtesy of Alireza Mashhadimirza.

Te stacked brick screen façade in the House of 40 Knots is also inspired by the process of weaving traditional carpets. Long elegant bricks are drilled with holes and woven into steel rod structures connected at each foor plate. Te brick screen creates a topography in both the elevation and the three-dimensional surface at each foor (Figure  4.69). Te height of each brick screen varies to create a dynamic façade, but also the screen functions as a guardrail for the full height windows. Te brick assembly at each foor is independent from

225

Why Stack?

FIGURE 4.65 Construction process at the Brick Pattern House. Photo: courtesy of Alireza Mashhadimirza.

the brick screen above and below. A horizontal steel member supports the brick assembly at the foor level, so the weight of the stacked brick at the top of the building does not bear down on the bricks below. For this façade, Mashhadimirza and his colleague, Madjabadi, also provided an installation pattern for construction. Te façade is composed of raised, fller, and hollow bricks. No mortar is used. Steel angles are intermittently incorporated to keep the struc­ ture square (Figure 4.70). Te raised brick is threaded with the steel rods. In the assembly

226

What Happens When Stacking?

FIGURE 4.66 Window detail of brick facade. Photo: cour­ tesy of Alireza Mashhadimirza.

instructions, the void between bricks is called a ‘hollow’ brick. Te fller brick is free from the steel rod and cantilevers of the brick screen like the bricks are the Brick Pattern House. However, in this project, the fller brick is held by the weight of the raised bricks bearing on each other. Te lacy brick façade is threaded together but the steel rods stop at varying heights. So, the weight of the bricks plays a signifcant role in the structuring of the façade but also in regulating porosity and opacity.

227

Why Stack?

FIGURE 4.67 House in a Green Neighborhood brick assembly detail. Photo: courtesy of Alireza Mashhadimirza.

FIGURE 4.68 Brick façade at House in a Green Neighborhood. Photo: cour­ tesy of Alireza Mashhadimirza.

228

What Happens When Stacking?

FIGURE 4.69 40 Knots House brick screen facade. Photo: courtesy of Alireza Mashhadimirza.

FIGURE 4.70 Weaving bricks at the 40 Knots House. Photo: courtesy of Alireza Mashhadimirza.

229

Why Stack?

STUDENT EXPERIMENT How Can We Manipulate a Stacking Module Tat Can Create Diferent Patterns of Light? Stefan Oliver | University of Florida Stefan was interested in the work of Erwin Hauer, who cast plaster modules that inter­ locked into one cubic unit that was then stacked into a screen assembly. Stefan wanted to design a stacking module that would also cast light but could be oriented in diferent bond patterns. Creating a module that forms an opening: In most stacked assemblies, the stack­ ing module is a solid form with faces that can support weight from other modules. In Hauer’s modules, each unit was composed of two complex geometric forms to capture light and shadow. Stefan wanted to maximize the module’s potential even further by trying to use the module in multiple orientations to produce diferent efects (Figure 4.71). Negotiating geometry: A typical brick module has six orientations that are used in stacked patterns. Stefan’s module was a U-shaped cube with legs at two diagonal edges of the module. Like Hauer’s modules, Stefan’s module pairs two of these forms together to make a stacking unit. Although the two forms do not physically inter­ lock together, as a unit, it captures diferent depths of light and creates a variation of shadow in the opening. Stefan eliminated mass within the module, so it produced a lighter block (Figure 4.72). Encountering issues of gravity and weight. Stefan drew stacking patterns that spec­ ulated on possible stacking patterns for his module. Stefan included staggered pat­ terns of his module. However, when he tested these patterns with his modules, his U-shaped forms were difcult to stagger because the distribution of mass in the module was of-balanced and unsupported. In drawings, we don’t have to deal with gravity, so any pattern orientation would theoretically work. Stefan’s propos­ als could not be dry stacked because there was no resistance between blocks to prevent it from toppling over. Te lightness of the modules could not work against gravity. Adhering the modules together would help in unifying the assembly, but the weight distribution within the module would challenge the stability of the assembly.

FIGURE 4.71

230

Drawing proposal of stacking patterns. Photo: Stefan Oliver.

What Happens When Stacking?

FIGURE 4.72

Stacked modules in a self-supporting pattern. Photo: Lisa Huang.

Mass and Lightness: How Do We Make Something Inherently Heavy Defy Its Own Weight? Tere is an inherent appearance of weight when modules stack together in a monolithic assembly. A brick load-bearing wall can reduce its thickness as it increases in height and carries less load, but we cannot necessarily perceive this change in its exterior appearance. Each module needs to have a mass and density so that it carries weight and bears on other modules for structural strength. Te solidness of the stacked wall provides a protective enclo­ sure. However, stacking is not limited to traditional associations of heaviness. Te following projects challenge the appearance of a conventional stacked assembly as a gravity-loaded con­ struction and tests new ways of addressing structural stability. Teir stacking modules may still bear weight on each other, but the assemblies are constructed so that they also convey lightness.

231

Why Stack?

Te Optical Glass House by Nakamura and NAP Architects redefnes the typi­ cal stacked assembly’s weight-bearing appearance. It is a new interpretation of stacked glass block in reference to a typical masonry wall. Like in the MVRDV’s Crystal Houses, the glass façade fully transmits light. However, in the Optical Glass House the stacked glass blocks are actually hung from the top of the facade. Te house has lightness within the interior from the transparent glass blocks but also lightness in that the glass blocks are alleviated of carrying weight in the façade. Six thousand custom cast glass units were used in the house. Each cast glass mod­ ule has the proportions of a masonry brick, approximately 9.25 inches by 1.9 inches (235mm × 50mm) instead of the standard six-inch or eight-inch square glass block size. Te glass module is customized to a shape that receives a steel structure of reinforcing bars and metal plates. Te glass module is cast with holes to accommodate vertical steel structure. Seventyfve threaded steel rods are threaded vertically through glass blocks that are set in a running bond pattern. Te steel rods hang from a pre-tensioned structural beam spanning the top of the façade. Although this construction is composed of stacked glass modules, it is not a stacked system where each module bears weight on modules and then to the foundation below. Instead, the bearing of the façade weight is inverted and all the cast glass blocks are hung from the steel structure. Horizontal metal fat bars that span the façade width support the weight of rows of glass blocks and help to resist lateral forces. Te glass block is installed from the bottom of the steel rods and leveled with bolts that hold the glass blocks in place. Each block bears minimal weight from the other glass blocks to reduce the possibility of the glass breaking. Te intermittent horizontal steel structure isolates structural stresses to only a few rows of stacked glass blocks. Te façade of Ventura Virzi Arquitectos’s Brick House in Buenos Aires stacks bricks into a screen for a three story in-fll house. On the ground foor, the brick assembly is solid and opaque to shield private spaces from the street. Above the ground foor, the stacked assembly achieves structural lightness as it becomes more open and delicate toward the top of the facade (Figure 4.73). Te proportion of the brick module is elegantly thin and narrow, similar to dimensions of a Roman brick. Ventura Virzi uses three orienta­ tions of the brick: stretcher, soldier, and rowlock to construct the façade’s bond pattern. Te entire brick facade has a depth of two wythes to create a three-dimensional grid with structural integrity. Te module pattern of the screen alternates rows of stretcher bricks with rows of soldier bricks. Four pattern variations assemble the thin brick modules into a lacy façade. Te opaque section of the brick façade meets the sidewalk with a row of soldier bricks set at every intersection with two stretcher bricks. Tis lifts the façade and allows light to enter into the ground foor space. Tis open grid of base bricks supports six rows of completely opaque and densely stacked bricks. Te brick facade is held of the ground by a window and emphasizes the façade’s lightness. On the second foor, the brick façade becomes a screen. Te lateral spacing of the base is repeated at the joint of two stretcher bricks. But in the vertical dimension, the height of the opening increases to a 1.5 module height. A soldier brick is stacked on top of a

232

What Happens When Stacking?

FIGURE 4.73 Brick façade of the Casa de Ladrillos. Photo: Gustavo Sosa Pinilla, cour­ tesy of Ventura Virzi Arquitectos.

rowlock brick. Additionally, the two wythes in the facade vertically shift from each other to strengthen the three-dimensional structure (Figure 4.74). Te exterior face of bricks staggers from the interior face of bricks to create shadow within the screen and depth in the façade surface. At the top foor of the house, the brick screen at the roof terrace becomes even more open by omitting every other soldier brick. Te joint between two stretcher bricks is only connected with mortar; another brick does not support at the joint. Troughout the façade, the thin brick modules appear as though they defy gravity. Te vertically oriented soldier bricks and the horizontally oriented stretcher bricks minimally overlap each other. Te lightness of the assembly is exaggerated by the stacking of thin brick modules that do not appear to have additional support. Te only visible steel component spans the facade opening above the front door. Te brick facades turn in at the front entrance and at the roof terrace, so the brick façade is not just a face for the house but it also interlocks with spaces in the house. Te project intelligently uses depth and interlocking modules between wythes to lighten the weight of the assembly and to emphasize lightness in the façade. In Kengo Kuma’s Yusuhara Wooden Bridge Museum, laminated veneer lumber (LVL) made of local cedar is stacked to cantilever an enclosed bridge connecting buildings

233

Why Stack?

in the museum’s complex. Te structure of the museum refer­ ences traditional Japanese wood constructions. Each cedar LVL girder is laminated with eleven horizontal layers of cedar planks to produce a bridge girder that is seven inches × 11.8 inches in cross section. Te entire bridge structure is supported using one central column that is made of steel and enclosed with cedar. Wood girders are then stacked in an inverted pyramid form. Girders running parallel to the bridge incrementally increase in length to meet the full span of the bridge. Parallel to the museum’s width, shorter girders cantilever in between the long girders to create an airy porous structure (Figure 4.75). Across and along the bridge, the girders stagger to allow the structure to lengthen with each row of timbers. When the wood girders intersect, the bottom edge is notched to lock the girders together and then they are also bolted with a bracket system. Tis interlocks the girders into a uniform structure where the weight of the museum carries down to the central pillar (Figure 4.76). Te wood girder structure foats above the ground in a dramatic fashion. Te museum cantilevers of a sin­ gle column and the wood structure appears light and airy. Te wood girders minimally touch adjacent girders. Te ends of each wood girder are white in that they are covered with powdered shellfsh. Tis traditional Japanese method called kofun protects the wood against water erosion. Kuma’s design for the structure is simi­ lar to Zumthor’s Swiss Sound Box in that the stacked wood girders not only create an elabo­ rate and elegant structure, but also allows the wood structure to shed moisture. Structural innovations in stacking are a means to explore alternative strategies in addressing the visual and physical weight associated with stacked materials. In a typical load-bearing masonry structure, the weight is accumulated from modules stacking one on

FIGURE 4.74 Casa de Ladrillos detail of two wythes in the three-dimensional assembly. Photo: Gustavo Sosa Pinilla, courtesy of Ventura Virzi Arquitectos.

FIGURE 4.75 Structural form of the Yusuhara Wooden Bridge Museum. Photo: Takumi Ota, courtesy of Kengo Kuma Associates.

234

What Happens When Stacking?

FIGURE 4.76 Detail of the stacked LVL gird­ ers. Photo: Takumi Ota, courtesy of Kengo Kuma Associates.

top of the other. Each module is typically heavy so that it uses gravity to stabilize the struc­ ture. In the Lions Park Scout Hut, Rural Studio redefnes the role and character of weight in the building assembly. Te weight of stack modules shifts from its typical location in a wall assembly. Rural Studio has a series of projects experimenting with using thinnings in con­ struction (Figure 4.77). Tinnings are pine trees removed to thin out dense overcrowding in forests. Tis process helps with the growth rate and overall health of trees. In the Lions Park Scouts Hut, Rural Studio transforms the image of the typical log cabin in an unconventional

FIGURE 4.77 Lions Scout Hut, uses thinnings as ballast. Photo: Timothy Hursley.

235

Why Stack?

FIGURE 4.78 Rural studio’s testing ground for full-scale mock-ups. Photo: Lisa Huang.

way (Figure 4.78). Tin wood timbers are used as bents to structure a simple building frame of trusses and columns. Te bents extend past the building enclosure to frame a rack that holds stacked piles of thinnings. Te thinnings are dry stacked in this outer rack and serve two important purposes: they are a cladding for the building facade and they act as a ballast to hold down weight of structure. Te thickness of the stacked wood logs bufers the building from wind, rain, and sun exposure. Instead of stacking modules to stabilize structure through compression, the entire log pile stabilizes the structural frame in tension. Steel cables in the trusses equalize the forces generated by the weight of the ballast. Tis structural strategy reduces the foundation requirements and the amount of concrete required for the project. Ballasts on the exterior of the building allow the building interior to be very open. Te structure exposed on the interior is an assembly of thin wood members and steel tension cables. Weight and placement of the wood logs provide structural strength in the build­ ing; however, this also allows the building’s structure to lightly touch the ground. A continu­ ous clerestory window at the base of the building, like at the Ventura Virzi Brick House, emphasizes the lightness of the structure and enclosure. Te entire building enclosure foats above the ground redefning the typical log cabin. Sou Fujimoto’s Final Wooden House in Kumamoto also challenges the traditional log cabin construction through a change of scale in the stacking module. In this house, cedar wood blocks, 13.8 inches (350 mm) square in profle, are stacked into a perfect cube build­ ing form 13.8 feet in its dimensions (Figure 4.79). Tese wood blocks however are not just the exterior wall assembly but the stacked timber is the enclosure, structure, vertical circula­ tion, and interior walls. Te stacked modules’ length, orientation, and organization shape the functional spaces within the house. Te 13.8-inch dimension establishes the structural grid in the x-, y-, and z- orientations. It is also a dimension comfortably proportioned to the human body. Te stacked wood blocks can simultaneously function as steps, seating, tables, or sleeping platforms. Te interior of the house is a continuous space with playful overlapping func­ tions (Figure 4.80). Except for the bathroom, there are no interior doors separating rooms. Fujimoto carves out space within the 13.8-foot stacked wood cube, but the occupant decides how to use the space. Te vertical exterior openings in the structure are inflled with indi­ vidual glass planes tilted at 30 degrees. Skylights at the top of the house are waterproofed using a sheet of glass that is fastened across the whole building and sloped for water drainage. Tis glass roof is a continuous plane to emphasize the purity of the assembly.

236

What Happens When Stacking?

FIGURE 4.79 Stacked timber composing the Final Wooden House. Photo: Jeff Gaines.

FIGURE 4.80 Interior spaces defned by the stacked timber. Photo: Jeff Gaines.

237

Why Stack?

Te house’s construction is extremely unique in that it appears as a pure represen­ tation of a stacked assembly. Te large wood blocks cantilever and hover in the air, seemingly unchallenged by gravity and weight. To perpetuate this illusion, the design of the connection detail is critical in allowing timber blocks to hover. Timber blocks are bolted together to sta­ bilize the structure. Each bolt has an integrated spring coil to provide structural tension and accommodate movement in the stacked assembly. A wood cap covers the hidden bolt struc­ ture to preserve the appearance of a solid timber block. Instead of the conventional stacking principle of gravity bearing weight on each module, the entire assembly of a house is bound together as a singular structural module. Fujimoto’s Wooden House captures the appearance of a stacked assembly, but its structural integrity challenges conventional structural strategies for a stacked assembly.

Notes 1 2 3 4

238

Remo Pedreschi and Gonzalo Larrambebere, “Technology and Innovation in the Work of Eladio Dieste,” in Eladio Dieste: Innovation in Structural Art, ed. Stanford Anderson, (New York: Princeton Architectural Press, 2004), 147–148. Jane Ahlin, Sigurd Lewerentz, Architect, 1885–1975, (Cambridge: MIT Press, 1987), 167. Ibid., 171. Wilfred Wang, “Te Transcendence of Artchitecture,” in Te O’Neil Ford Monograph Series, Volume 2, St Petri Church, (Austin, TX: Center for American Architecture and Design and Ernst Wasmuth Verlag, 2009), 19.

Bibliography

Aalto, Alvar, Shigeru Ban, Barbican Art Gallery, Juhani Pallasmaa, and Tomoko Sato. Alvar Aalto: Trough the Eyes of Shigeru Ban. London: Black Dog Publishing: in association with Barbican Art Gallery, 2007. Ahlin, Janne. Sigurd Lewerentz, Architect, 1885–1975. 1st English language ed. Cambridge, MA: MIT Press, 1987. Ahlin, Janne and Wilfried Wang. Saint Petri Church: Klippan 1962–66. Austin, TX: Center for American Architecture and Design and Ernst Wasmuth Verlag, 2009. Allen, Edward and Joseph Iano. Fundamentals of Building Construction: Materials and Methods. 4th ed. Hoboken, NJ: John Wiley & Sons, 2004. Allied Works Architecture, Brad Cloepfl, and Clyford Still. Allied Works Architecture: Clyford Still Museum. Ostfldern, Germany: Hatje Cantz, 2013. Alread, Jason, Tomas Leslie, and Rob Whitehead. Design-Tech. 2nd ed. New York, NY: Routledge, 2014. Anderson, Stanford, Eladio Dieste, and Eladio Dieste. Eladio Dieste: Innovation in Structural Art. New York, NY: Princeton Architectural Press, 2004. Andō, Tadao, Francesco Dal Co, and Vittorio Gregotti. Tadao Ando: Complete Works. London: Phaidon, 1995. Architectural League of New York. Young Architects 4: Material Process. 1st ed. New York, NY: Princeton Architectural Press/Architectural League of New York, 2003. Armijos, Samuel J. and Bill Lassiter honoree. Fabric Architecture: Creative Resources for Shade, Signage, and Shelter. 1st ed. New York, NY: W.W. Norton, 2008. http://www.ufib.uf.edu/ tools/bookplate/donor.htm?donor=Gift in memory of: Bill Lassiter. Art Institute of Chicago, Jeanne Gang, Zoë Ryan, and Studio Gang Architects. Building: Inside Studio Gang Architects. Chicago, IL: Studio Gang Architects in association with the Art Institute of Chicago, 2012. Balmond, Cecil, Nobuyuki Yoshida, and 吉田信之. Cecil Balmond = Seshiru Barumondo; Cecil Balmond = セシル・バルモンド. Tokyo: A + U Publishing Co, 2006. Ban, Shigeru, Lauren A. Gould, Ian Luna, and Riichi Miyake. Shigeru Ban: Paper in Architecture. New York, NY: Rizzoli International Publications, 2009.

239

Bibliography

Barozzi Veiga (Firm), Harquitectes (Firm), Richard C. Levene, MGM (Architectural Firm), Fernando Márquez Cecilia, and SelgasCano (Firm). MGM, Barozzi Veiga, Harquitectes, Selgascano: Cuatro Estrategias = Four Strategies 2015. Madrid: El Croquis Editorial, 2015. Bauchet, Bernard, Marc Vellay, and Yukio Futagawa. La Maison De Verre by Pierre Chareau. Tokyo: A.D.A. Edita Tokyo, 1988. Bell, Victoria Ballard and Patrick Rand. Materials for Design. 1st ed. New York, NY: Princeton Architectural Press, 2006. Bell, Victoria Ballard and Patrick Rand. Materials for Design 2. 1st ed. New York, NY: Princeton Architectural Press, 2014. Bennett, David. Exploring Concrete Architecture: Tone, Texture, Form. Basel: Birkhäuser, 2001. Bennett, David. Te Art of Precast Concrete: Colour Texture Expression. Basel: Birkhäuser, 2005. Berger, Horst. Light Structures, Structures of Light: Te Art and Engineering of Tensile Architecture. Basel/Boston, MA: Birkhäuser Verlag, 1996. Bhatia, Gautam and Housing and Urban Development Corporation. Laurie Baker: Life, Work, Writings. New Delhi/New York, NY: Penguin Books, 1994. Billington, David P. Robert Maillart and the Art of Reinforced Concrete. New York, NY/ Cambridge, MA: Architectural History Foundation/MIT Press, 1990. Blaser, Werner and Ludwig Mies van der Rohe. Mies Van Der Rohe: Te Art of Structure. New York, NY: Whitney Library of Design, 1994. Bognár, Botond and Kengo Kuma. Kengo Kuma: Selected Works. New York, NY: Princeton Architectural Press, 2005. Bognár, Botond and Kengo Kuma. Material Immaterial: Te New Work of Kengo Kuma. 1st ed. New York, NY: Princeton Architectural Press, 2009. Brownlee, David Bruce, David Bruce Brownlee, David Gilson De Long, Grant Mudford, and Vincent Jr Scully. Louis I. Kahn: In the Realm of Architecture. Condensed ed. New York, NY/Los Angeles, CA/New York, NY: Universe Pub./Museum of Contemporary Art/Distributed to the U.S. trade by St. Martin's Press, 1997. Celant, Germano. Prada Aoyama Tokyo: Herzog & De Meuron. Milan: Fondazione Prada, 2003. Centre Canadien d'Architecture, Herzog & de Meuron, Schaulager, and Philip Ursprung. Herzog & De Meuron: Natural History. Montreal/Baden, Switzerland: Canadian Centre for Architecture/Lars Müller, 2002. Chilton, John and Heinz Isler. Heinz Isler. London: Tomas Telford, 2000. Corbusier, Le. Te Chapel at Ronchamp. New York, NY: Praeger, 1957. Croft, Catherine. Concrete Architecture: An American Classic. Salt Lake City, UT: Gibbs Smith, Publisher and Laurence King Pubishing, 2004. Davids, René and Christine Killory. Details in Contemporary Architecture. 1st ed. New York, NY: Princeton Architectural Press, 2007. De Alba, Roberto. Paul Rudolph: Te Late Work. 1st ed. York, NY: Princeton Architectural Press, 2003. Dean, Andrea Oppenheimer, Auburn University School of Architecture, Lawrence Chua, Timothy Hursley, and Cervin Robinson. Rural Studio: Samuel Mockbee and an Architecture of Decency. 1st ed. New York, NY: Princeton Architectural Press, 2002.

240

Bibliography

Dent, Andrew H. and Leslie Sherr. Material Innovation: Architecture. New York, NY: Tames & Hudson, 2014. Deplazes, Andrea. Constructing Architecture: Materials, Processes, Structures, a Handbook. Basel/Boston/London: Birkhäuser/Springer Distributor, 2005. Detail. Best of Detail: GLAS/GLASS: Transparenz Versus Transluzenz / Transparency Versus Translucence, 2014. S.l: Detail. http://www.degruyter.com/doi/book/10.11129/detail. 9783955532031 and http://www.degruyter.com/search?f_0=isbnissn&q_0=97839555320 31&searchTitles=true. Dieste, Eladio, Intendencia Municipal Montevideo (Uruguay), and Facultad de Architectura, Universidad de la Rebública (Uruguay). Eladio Dieste. Montevideo, Uruguay: IMM, 2003. Domin, Christopher and Joseph King. Paul Rudolph: Te Florida Houses. 1st ed. New York, NY: Princeton Architectural Press, 2002. Faber, Colin. Candela, the Shell Builder. New York, NY: Reinhold Pub. Corp, 1963. Flora, Nicola, Nicola Flora, Paolo Giardiello, Sigurd Lewerentz, Gennaro Postiglione, and John Wilson St. Sigurd Lewerentz: 1885–1975. Milano: Electa architecture, 2002. Freear, Andrew, Elena Barthel, Andrea Oppenheimer Dean, and Timothy Hursley. Rural Studio at Twenty: Designing and Building in Hale County, Alabama. 1st ed. New York, NY: Princeton Architectural Press, 2014. Gang, Jeanne and Studio Gang Architects. Reveal: Studio Gang Architects. 1st ed. New York, NY: Princeton Architectural Press, 2011. Gargiani, Roberto, Le Corbusier, Steve Piccolo (translator), and Anna Rosellini. Le Corbusier: Béton Brut and Inefable Space, 1940–1965: Surface Materials and Psychophysiology of Vision. 1st ed. Lausanne, Switzerland/Abingdon, Oxford/New York, NY: EFPL Press/ Distributed by Routledge, 2011. http://bvbr.bib-bvb.de:8991/F?func=service&doc_ library=BVB01&doc_number=022557580&line_number=0001&func_code=DB_ RECORDS&service_type=MEDIA and http://bvbr.bib-bvb.de:8991/F?func=servi ce&doc_library=BVB01&doc_number=024580184&line_number=0001&func_ code=DB_RECORDS&service_type=MEDIA. Garlock, Maria E. Moreyra, David P. Billington, and Art Museum Princeton University. Félix Candela: Engineer, Builder, Structural Artist. Princeton, NJ/New Haven, CT: Princeton University Art Museum/Yale University Press, 2008. Glynn, Ruairi and Bob Sheil. Fabricate: Making Digital Architecture. Toronto: Riverside Architectural Press, 2011. Gonzalez Blanco, Fermin. Miguel Fisac: Huesos Varios. 1st ed. Madrid: Fundación COAM, 2007. Goodwin, Kate. Dandelion: Te Making of the UK Pavilion at Shanghai World Expo 2010. S.l: London: British Council, 2011. Gramazio & Kohler [translations: Laura Bruce, Monica Buckland]. Gramazio & Kohler: Digital Materiality in Architecture. Baden: Lars Müller Publishers, 2008. Hauer, Erwin. Erwin Hauer: Continua, Architectural Screen Walls. New York, NY: Princeton Architectural Press, 2004. Heatherwick, Tomas. Tomas Heatherwick: Making. 1st ed. New York, NY: Te Monacelli Press, 2012. Herzog & de Meuron and Gerhard Mack. Herzog & De Meuron: Das Gesamtwerk = Te Complete Works. Basel/Boston, MA: Birkhäuser, 1996.

241

Bibliography

Herzog & de Meuron; text: Gerhard Mack. Elbphilharmonie Hamburg. Basel: Birkhauser, part of Walter de Gruyter GmbH, Berlin, 2018. http://apps.ufib.uf.edu/PrintMonoPDA/ default.aspx?ISBN=9783035616033&Title=Elbphilharmonie Hamburg&Author=&HA RRId=har185004945. Herzog, Jacques, Richard C. Levene, Pierre de Meuron, and Fernando Márquez Cecilia. Herzog & De Meuron 1981–2000. Madrid: El Croquis, 2005. Hofmeister, Sandra. Architecture and Construction Details: Herzog & De Meuron. Munich: DETAIL Business Information GmbH, 2017. Howey, John. Te Sarasota School of Architecture: 1941–1966. 1st MIT Press pbk. ed. Cambridge, MA: MIT Press, 1997. Iannacci, Anthony and Shoei Yoh. Shoei Yoh: In Response to Natural Phenomena. Milano: L'arca, 1997. Jodidio, Philip. Álvaro Siza. Köln/Los Angeles, CA: Taschen, 2003. Jodidio, Philip. Architecture Now! = Architektur Heute = L'Architecture D'Aujourd'Hui. Köln/ London: Taschen, 2010. Jodidio, Philip and Florian Kobler. Shigeru Ban, 1957: Architecture of Surprise. Köln/Los Angeles, CA: Taschen, 2012. Kieran, Stephen, Kieran Timberlake (Firm), and James Timberlake. Cellophane House: KieranTimberlake. Philadelphia, PA: KieranTimberlake, 2011. Koch, Klaus Michael, Brian Forster, Karl J. Habermann, and Klaus Michael Koch. Membrane Structures: Innovative Building with Film and Fabric. Munich/New York, NY: Prestel, 2004. Krippner, Roland, Werner Lang, and Christian Schittich. Building Skins. New enl. ed. München/Basel Switzerland/Boston, MA: Edition Detail/Institut für internationale Architektur-Dokumentation/Birkhäuser, 2006. Kula, Daniel, Quentin Hirsinger, MatériO (Firm), and Elodie Ternaux. Materiology: Te Creative's Guide to Materials and Technologies. Amsterdam/Basel/Boston, MA: Frame Publishers/Birkhäuser, 2009. Kuma, Kengo. Kengo Kuma: Materials, Structures, Details. Basel/Boston, MA: BirkhäuserPublishers for Architecture, 2004. Kuma, Kengo, Kenneth Frampton, Mariko Inaba, and Hiroshi Watanabe. Kengo Kuma: Complete Works. New York, NY: Tames & Hudson, 2013. Leoni, Giovanni. Álvaro Siza. 1st ed. Milan: Motta Architettura, 2009. Lewerentz, Sigurd and Architectural Association (Great Britain). Sigurd Lewerentz, 1885– 1975: Te Dilemma of Classicism. London: Architectural Association, 1989. Lewerentz, Sigurd, Claes Caldenby, Adam Caruso, Olof Hultin, and Sven Ivar Lind. Two Churches = Två Kyrkor. Stockholm, Sweden: Arkitektur Förlag AB, 1997. Löschke, Sandra Karina. Materiality and Architecture. London/New York, NY: Routledge, 2016. Loughran, Patrick. Failed Stone: Problems and Solutions with Concrete and Masonry. Basel/ Boston, MA: Birkhäuser, 2007. Loughran, Patrick. Falling Glass: Problems and Solutions in Contemporary Architecture. Basel/ Boston, MA: Birkhäuser-Publishers for Architecture, 2003. MacDonald, William Lloyd. Te Pantheon: Design, Meaning, and Progeny. Cambridge, MA: Harvard University Press, 1976.

242

Bibliography

Mack, Gerhard. Herzog & De Meuron: Das Gesamtwerk = the Complete Works. 2nd ed. Basel/ Boston: Birkhäuser, 2005. Mack, Gerhard. Herzog & De Meuron, 1997–2001. Basel/London: Birkhäuser/Springer Distributor, 2009. Mack, Gerhard and Valeria Liebermann. Eberswalde Library: Herzog & De Meuron. London: Architectural Association, 2000. Márquez Cecilia, Fernando and Richard Levene. Herzog & De Meuron: 2005/2010. Madrid: El Croquis, 2010a. Márquez Cecilia, Fernando and Richard Levene. Sou Fujimoto: 2003/2010. Madrid: El Croquis, 2010b. McCarter, Robert. Frank Lloyd Wright. London: Phaidon Press, 1997. McCarter, Robert. Louis I. Kahn. London/New York, NY: Phaidon, 2005. McCarter, Robert and Alvar Works Selections Aalto. Aalto. London: Phaidon Press, 2014. Merkel, Jayne. Eero Saarinen. London/New York, NY: Phaidon, 2005. Monk, Tony and Norman Foster. Te Art and Architecture of Paul Rudolph. Chichester: Wiley-Academy, 1999. Murray, Scott. Translucent Building Skins: Material Innovations in Modern and Contemporary Architecture. London/New York, NY: Routledge, 2013. Museum Villa Stuck and Werkbund Bayern. Frei Otto, Bodo Rasch: Finding Form: Towards an Architecture of the Minimal: Te Werkbund Shows Frei Otto, Frei Otto Shows Bodo Rasch: Exhibition in the Villa Stuck, Munich, on the Occasion of the Award of the 1992 Deutscher Werkbund Bayern Prize to Frei Otto and Bodo Rasch. Stuttgart: Axel Menges, 1995. Nervi, Pier Luigi. Aesthetics and Technology in Building. Cambridge, MA: Harvard University Press, 1965. Nervi, Pier Luigi. Structures. New York, NY: McGraw-Hill Book Co., Inc, 1956. Neufert, Ernst, Bousmaha Baiche, Peter Neufert, Nicholas Walliman, and Nicholas S. R. Walliman. Architects’ Data. 3rd ed./edited by B. Baiche and N. Walliman. Malden, MA: Blackwell Science Publishers, 2000. Nicholas, Paul and Kunstakademiet (Denmark) Arkitektskolen Center for Informations Teknologi, og Arkitektur. Designing Material, Materialising Design. 1st ed. Toronto: Riverside Architectural Press, 2013. Otto, Frei, Ludwig Glaeser, and Museum of Modern Art. Te Work of Frei Otto. New York, NY: Museum of Modern Art; distributed by New York Graphic Society, Greenwich, CT, 1972. Otto, Frei, Winfried Nerdinger, and Architekturmuseum der Technischen Universität München. Frei Otto: Complete Works: Lightweight Construction, Natural Design. Basel/ Boston, MA: Birkhäuser, 2005. Otto, Frei, Friedrich Karl Schleyer, and Rudolf Trostel. Tensile Structures; Design, Structure, and Calculation of Buildings of Cables, Nets, and Membranes. Cambridge, MA: Te MIT Press, 1973. Patterson, Terry L. Frank Lloyd Wright and the Meaning of Materials. New York, NY: Van Nostrand Reinhold, 1994. Pauly, Danièle. Le Corbusier: Te Chapel at Ronchamp. Paris/Basel/Boston, MA: Fondation Le Corbusier/Birkhäuser, 2008. Peck, Martin. Concrete: Design Construction Examples. Basel/Munich: Birkhäuser/Edition Detail, 2006.

243

Bibliography

Pedreschi, Remo. Eladio Dieste. London/Reston, VA: Tomas Telford/Distributors, USA, ASCE Press, 2000. Pell, Ben. Te Articulate Surface: Ornament and Technology in Contemporary Architecture. Basel/London: Birkhäuser/Springer Distributor, 2010. Petit, Jean and Le Corbusier. Le Livre De Ronchamp, Le Corbusier. Paris: Les Cahiers Forces Vives/Editec, 1961. Pfeifer, Günter, Per Brauneck, Antje Leibers, and Antje M. Liebers. Exposed Concrete: Technology and Design. Basel/Boston, MA: Birkhäuser, 2005. Ransom, W. H. Building Failures: Diagnosis and Avoidance. 2nd ed. London/New York, NY: E. & F.N. Spon, 1987. Ray, Nicholas. Alvar Aalto. New Haven, CT: Yale University Press, 2005. Rohan, Timothy M. Te Architecture of Paul Rudolph. New Haven, CT: Yale University Press, 2014. Román, Antonio. Eero Saarinen: An Architecture of Multiplicity. 1st ed. New York, NY: Princeton Architectural Press, 2003. Rudolph, Paul, Yukio Futagawa, and Rupert Spade. Paul Rudolph. London: Tames and Hudson, 1971. Saarinen, Eero, Donald Albrecht, Eeva-Liisa Pelkonen, and Taidehalli (Helsinki, Finland). Eero Saarinen: Shaping the Future. New Haven, CT: New York, NY: Helsinki: Washington, DC/New Haven, CT: Yale University Press/In Association with the Finnish Cultural Institute in New York/Museum of Finnish Architecture/Te National Building Museum/ Yale University School of Architecture, 2006. Schittich, Christian. Best of DETAIL: Beton. 1st ed. Munich: Institut für Internationale Architektur-Dokumentation GmbH & Co, 2016. Semper, Gottfried, Getty Research Institute, Harry Francis Mallgrave, and Michael Robinson. Style in the Technical and Tectonic Arts, or, Practical Aesthetics. Los Angeles, CA: Getty Research Institute, 2004. Sippo, Hanni. Alvar Aalto: Te Brick/Editor, Hanni Sippo. Helsinki: Alvar Aalto Museum, Alvar Aalto Foundation, 2001. Siry, Joseph. Unity Temple: Frank Lloyd Wright and Architecture for Liberal Religion. Cambridge, England/New York, NY: Cambridge University Press, 1996. Snöhetta. Snøhetta: Collective Intuition. London: Phaidon Press Limited, 2019. Stacey, Michael and Concrete Centre (Great Britain). Concrete: A Studio Design Guide. London: RIBA Publishing, 2011. Temko, Allan. Eero Saarinen. New York, NY: G. Braziller, 1962. Toxey, Anne Parmly. Materan Contradictions: Architecture, Preservation and Politics. Surrey, England: Ashgate Publishing Limited, 2011. Treib, Marc. Space Calculated in Seconds: Te Philips Pavilion, Le Corbusier, Edgard Varese. Princeton, NJ: Princeton University Press, 1996. Udovicki-Selb, Danilo. “Le Corbusier and the Paris Exhibition of 1937: Te Temps Nouveaux Pavilion.” Journal of the Society of Architectural Historians 56, no. 1 (1997): 42–63. Vellay, Dominique and François Halard. La Maison De Verre: Pierre Chareau's Modernist Masterwork. London: Tames & Hudson, 2007. Wang, Wilfried. Herzog & De Meuron. 3rd enlarged ed., Bilingual original ed. Boston, MA: Birkhauser, 1998.

244

Bibliography

West, Mark. Te Fabric Formwork Book: Methods for Building New Architectural and Structural Forms in Concrete. New York, NY: Routledge, 2017. Wever, Peter. Inside Le Corbusier's Philips Pavilion: A Multimedial Space at the 1958 Brussels World's Fair. Rotterdam: Nai010 Publishers, 2015. Yoon, J. Meejin and Eric Höweler. “Zero Tolerance.” ARPA Journal, no. 04 (2016). Zaera, Alejandro. Herzog & De Meuron, 1983–1993. Madrid: El Croquis Editorial, 1993. Zaugg, Rémy, Centre Georges Pompidou, Herzog & de Meuron, and Kunsthaus Bregenz Archiv, Kunst Architektur. Herzog & De Meuron: An Exhibition. English ed. OstfldernRuit: Cantz, 1996. Zumthor, Peter. Peter Zumthor. Tokyo, Japan: A + U Publishing, 1998. Zwerger, Klaus. Wood and Wood Joints: Building Traditions of Europe and Japan. Basel/ Boston, MA: Birkhauser, 1997.

245

Index

Note: Page numbers in italics denote fgures Aalto, Alvar 175, 205–206, 211 Acconci, Vito 39 acrylic rods 73, 74 Adalaj stepwell 146 adobe bricks 173, 174, 190 aggregate exposure 99–101, 101 air-purifying concrete 80–81 Alice Millard House 179 Allianz Arena 6, 7, 9, 18, 19 Allied Works 115, 118–119 aluminum 70, 70, 71, 109–110, 110 Amateur Architecture Studio 183–184 American Folk Art Museum 112–113, 113, 114, 115 Anagram Architects 214 Ando, Tadao 85–86, 88, 112, 119 apertures: in metal façades 54, 112, 114; natural light and 124; precision in 121–123; in stretched fabric 30; wood carving and 151, 155–156, 156, 157 Archi-Union Architects 178 Arcus Center for Social Justice Leadership (Kalamazoo, Michigan) 182, 183 Ark Nova 19, 21, 22 Arturo Franco Ofce for Architecture 183, 185 Atabey, Ali 216 AU Ofce and Exhibition Space 178 Baker, Laurie 221 Baker House (MIT) 175, 176 Ban, Shigeru 47–48, 87, 164 Barkow Leibinger 33 Bar Raval 162 Basento Bridge 135, 135 Basketball Arena (London Olympics) 14, 15, 16 Beecken, Tim 74 Behnisch, Günther 8 Behnisch Architekten 34 Berlinische Galerie 16 beton brut 98 Blueprint installation 39, 39, 40 brick assemblies: adobe 173, 174, 190; clinker 175–176, 176; form and 204–205; historical use of 171, 191; kilns for fring 190, 190; lightness in

232; masonry 174–175; mortar application and 207–211; pattern in 205–207, 207, 209, 209, 210, 210, 211–212, 214; qualities to consider 175; refnement in 202–205; rosette window 204, 205; rotated 220, 220, 221, 221; screens 220, 220, 223–227, 232, 233; standard size 175; texture and shadow in 211–212, 214; threedimensionality in 189; twisting 214, 215, 216; veneer cladding 176, 198, 203–204, 211–212 Brick House (Buenos Aires) 232 Brick Pattern House 224, 224, 225, 226, 227 Brick Weave House 220, 220 Brion Cemetery 104, 104, 105–107, 109 Bruder Klaus Chapel 114–115, 116, 117 Brussels Expo (1958) 24 Brutalist architecture 99 Bryant Haybale House 186, 188 building scale: carving and 143–145, 148, 150; casting and 63, 137; reinforcement and 84; stretching materials and 3–4 Burnham & Root 196 Burnham Pavilion (Chicago) 12, 13, 14, 15 bush hammering 65, 85, 97, 99, 152 Candela, Felix 10, 76, 127–130, 134–135 Cardboard Bale House 186, 188 carpet tiles 185 carving: 3D scanners and 161; apertures and 151; assembly requirements 154; building scale and 143–145, 148, 150; cave dwellings 143, 145, 148; component scale and 150–152, 155; etching and 151; experimentation and xxiv; failures/ limitations in 155; form in 158–162; material selection and 152–153; material waste in 155; milling equipment for 154; organic shapes in 158, 162; process of 150; stepwells 144–145, 146; structural integrity and 162–168; surface texture and 150; three-dimensional shaping in 154; unpredictability in 158; wood assemblies 159–161, 161, 162, 165–166; wood components and 164–166; see also casting materials; wood carving

247

Index

carving materials: concrete 151–152; earth and 143–145, 148, 150, 152; milled stone 158–159, 159, 160; selection of 152–153; stone and 166–168; wood 150–151 Casa Cava (Matera, Italy) 148, 148, 149 Casa de Ladrillos 233, 234 cast acrylic resin 73 cast aluminum 70, 70 cast assemblies 61–63 cast bronze panels 112–113, 115 cast concrete: acoustical needs and 123–124, 125; aggregate exposure in 99–101, 101; air-purifying 80–81; cofers in 61–62, 63; cold joints in 96, 102, 103, 104; composition of 64–65; concrete screens 124, 126; consistency in 94; fabric-formed 137–138; fber optics and 74–75, 75; fuidity in 134–138; form and lightness in 125–133; gun-placed 62; imperfections/ irregularities in 97–100, 102, 104–107, 112, 114–115, 117–119; light-transmitting 74–75, 75, 76–77; manipulation of 76; moisture and 130; plasticity and mass in 134–139; power washing and 100, 152; refning surface texture in 65–66, 119–124; Roman Empire and 61–62; steel reinforcement in 65, 84, 122; surface texture and 98, 98, 99, 105–106, 106, 107, 108, 112, 114–115, 117–119; technique for 62; thermal assemblies in 131; thinness and 138–139; tile details in 107, 109; translucent 76; ultra-high­ performance 77–80; unpredictability in 63, 112; weathering and 98–99; ziggurat patterns in 105, 105, 106–107; see also concrete shells cast glass see glass casting casting materials: air-purifying concrete 80–81; aluminum 70, 70, 71, 109–110, 110; atypical 76–80; cast iron and metal alloys 69–70; cast stone as 66, 68; concrete as 61–66, 67, 76; formwork in 61; glass as 70–71, 71, 72, 72, 73; light-transmitting concrete 74–77; molds for 64; plaster as 66, 68, 68, 69; plastics 73, 74; selection of 81; ultra-high-performance concrete (UHPC) 77–80 casting process: architect involvement in 104–105; atypical formwork strategies 87–88; composite assemblies and 88–91, 93; formwork assembly 83–84, 87, 90, 98; formwork removal 85–86; imperfections/irregularities in 101; inconsistencies in 97–102, 104–107; insitu casting 81, 88–89; material behavior in 109–110; metal casting 109–110; missteps in 94–95, 95, 96, 96, 97; mixing ingredients 82; plaster models and 102, 103; releasing agent application 84–85; structural support in 83–84; treating surfaces 85–88, 89, 112; unpredictability in 82, 83, 84, 94, 97–99, 112; using ice/dry ice 110, 111; vibrating the mix 85 cast-in-place concrete: advantages of 63; composite assemblies and 88–91, 93; earth mound framework and 88; formwork in 62; paraboloid structures and 25, 127–128; PET bottle studs in 89, 91; scale of assembly and 81; surface texture and 115, 117–119, 119; thinness and 63 cast iron 69–70 cast stone 66 Catalan vaults 191 cave dwellings 143, 145, 148 Cement Hall (Zurich) 126–127

248

Centre for Architectural Structures & Technology (C.A.S.T.) 137–138 Centre Pompidou-Metz 47, 47–48, 87 chainmail fabric 40, 41, 42, 42 Chandigarh 25 channel glass 72, 72, 73 Chapel Lomas de Cuernavaca 128–129 Chapel of St. Ignatius 150–151, 151 Chareau, Pierre 180 Charles Ennis House 179, 179 China Academy of the Arts 28, 29, 30 Cho, Byoung-Soo 138 Chokkura Plaza 198, 198, 199, 200 Church of Christ the Worker (Atlantida) 201–202, 202, 203, 203, 204 clay roof tiles 183–185, 187 Clinica Mupag 137 clinker bricks 175, 176 Cloud 9 6 Clyford Still Museum 115, 117–118, 118, 119, 119, 124, 126 CMA 148 CNC milling 154–156, 158, 162, 168 coated fabrics 4–5 Cocoon House 25, 28 Cocoon plastic 25, 27, 27, 40 cofers 61–62, 93 cold joints 96, 102, 103 component scale: carving and 145, 150–152, 155; cast concrete and 97; casting and 63; cast iron and metal alloys 69; stacked materials and 171; stretched assemblies and 3–4; wood doors 150, 151, 152 composite assemblies: casting process and 88–91, 93; cast-in-place concrete and 88–91, 93; cofers in 93; concrete shells in 25, 91, 93; impact of heat and humidity on 27–28; precast concrete and 88–90; rigid/stretched materials in 24–25, 27–28; steel cables in 25, 27–29 computer numerical control (CNC) milling see CNC milling concrete see cast concrete concrete blocks 178–179 concrete masonry units (CMU) 178, 178, 179, 198 concrete precast panels see precast concrete concrete screens 124, 126 concrete shells: in composite assemblies 25, 91, 93; form and lightness in 126–133, 138; paraboloid structures 25, 127–128, 131–132; in stretched assemblies 10; waterproofng in 131–132 cordwood masonry 182, 183 corners: in apertures 121; brick and 189, 211–212, 214; cast concrete and 85–86, 96, 105, 123; glass blocks and 181–182, 182; metal panels and 52, 53; stone blocks and 199; stretched assemblies and 30, 40 Cosmic Rays Laboratory (Mexico City) 127–128, 128 Crystal Houses (Amsterdam) 219 Crystal Palace 69, 69 Cukrowisz Nachbar 89 David S. Ingalls Rink (Yale University) 131–132, 133 Dean Wolf Architects 212 Delft University of Technology (TU Delft) 219 Denver International Airport 6, 6 de Young Museum 54 Dieste, Eladio 201–205

Index

digital fabrication 117, 155, 158, 201 DiNicolo, Calvin 109 Djoser, Egypt pyramid 171, 172 Ductal 77–78, 78, 79–80, 163 Dude Cigar Bar 220, 220, 221 earth carving 143–145, 148, 150, 152 earth mound framework 88 Eberswalde Technical School Library 120, 120, 121, 152 elastic materials 24–25 Elbphilharmonie façade 56, 57 ePTFE fabric 18 etching 151 ETFE (Ethylene Tetrafuoroethylene) foils: air pressure and 6–7; assembly of 6; façades 7, 9, 34, 36; infated cushions and 17–18, 19; mechanical connections 18, 18; non-uniform geometry in 34; properties of 6; punctures and 8–9, 18; shadow/light in 33; solar screening and 6–7; tension and 34 expanded polystyrene (EPS) foam 163 Experimental House (Muuratsalo) 206, 206, 207, 207 experimentation xxi, xxiv, xxv, 8, 10, 34, 112, 137 fabric-formed concrete 137–138 fabric panels: assembly of 10–11; coated 4–5; ePTFE fabric 18; in framed assemblies 12–14; infated membranes and 18–19; precise components in 5–6; PVC fabric 19; reinforcement of 6; suspended assemblies and 11–12; three-dimensionality in 30 façades: apertures in 54, 112; brick screens 220, 220, 223–227, 232, 233; bricks in 189, 189, 214, 232; brick veneer cladding 176, 191, 196, 203–204, 204, 211–212; cast-in-place concrete and 89–90, 90–91, 115, 117–119; cold joints in 102, 102, 103, 104; concrete blocks in 178, 178; cordwood masonry 182, 183; embossed metal 54; ETFE foils and 34, 36; fberglass reinforced polymer (FRP) in 163; foating stacked 204; glass blocks in 180, 180, 181, 181, 182, 219; glass panels in 56, 57, 70, 71; granite stones in 123; metal mesh in 52, 53; metal panels 54–55, 55, 112–113, 113, 114, 114, 115; milled stone 158–159, 159, 160; natural light and 14, 30, 36; perforated screens 222–223; PET bottles in 89, 91; photographic images in 120, 120, 121; reclaimed building materials in 183–184, 184; refning roughness of 119–124; roof tiles in 28–29, 29, 30; stone cladding 173, 173, 198, 199; visible seams in 55; wood carving and 161, 167; wood cladding 150–151, 153, 158 failure: in carving 152, 155; in casting 94, 118, 127–130; design process and xxiii; materials and xxiii; in stacking 193; in stretching 24 Federal Garden Exposition (1955) 10 Fentress Architects 6 ferrocemento 91 fberglass reinforced polymer (FRP) 163 fber optics 73–75, 75 feldstones 173 Final Wooden House (Kumamoto) 236, 237 Fisac, Miguel 137 fexible membranes: apertures in 30; asymmetry and 34; clinging/draping in 36–37, 39–40, 42; coated fabrics 4–5; form in 4, 10, 36; lightness/

weight in 42, 44, 46–48; sagging in 33, 36; shadow/light in 33, 40; structural frames for 36–38, 38, 39, 39, 47–48; tension in 10–11, 30, 32–34, 36–37; three-dimensionality in 30; woven wood in 47; see also stretched assemblies fuidity: cast concrete and 102, 134–138; glass surfaces and 56; serpentine brick walls and 200–201; stretched materials and 24, 51; woven wood and 47 form: carving and 158–162; framed assemblies 12–14; lightness and 125–133; paraboloid structures 25, 127–128; pneumatic structures 18–19, 22; rigid materials and 51, 54; stacked assemblies and 204–205; steel cables and 34; stretched assemblies and 3–4, 10–11, 24, 40, 42; structural forces and 36; structure and 200 formwork: acoustical needs and 123; bamboo 87; cast concrete and 62, 83–87, 89–90; casting materials and 61; earth mound 88; fabric 137–138; as interior surface feature 87; pine tree trunks as 114–115; removal of 85; silicone 90; surface bulging and 85–86; surface texture and 94, 98, 105–106, 106, 107, 112, 114–115, 116, 117; wood scafolding 191 40 Bond Street 70, 70, 112 framed assemblies: ETFE foils and 6, 33–34, 36; fabric panels in 12–14; façade membranes 14–16; metal panels in 54; prefabrication of 14; shaped PVC fabric in 16–17; see also stretched assemblies Fujimoto, Sou 236, 238 Garden Smoking Pavilion 76, 77 Germany Pavilion 8, 11 Gianni Botsford Architects 76 glass blocks: cast assemblies 71, 72; cast concrete and 76; façades and 180–181, 182; hanging 232; as infll 180; light-transmitting 71–72, 76, 180, 219; load-bearing 219; stacked assemblies and 179–180 glass casting 70, 70, 71, 71, 72, 72 glass panels 56, 56–57, 58, 58, 73 Gramazio Kohler 158, 201 granite blocks 123, 166, 173 Great Exhibition of 1851 69 Great Mosque (Djenné) 174 Grotto Sauna 161–162 gun-placed concrete (gunite) 62 Haimerl, Peter 123 Hajj Terminal (Jeddah) 5, 5 Hammerite Kurust 70 Hanil Visitor Center and Guest House 138 Hannover Expo (2000) 223 Hauer, Erwin 230 Haworth Tompkins 189 hay bales 186 Head In exhibit (Berlinische Galerie) 16 Healy Guest House 24–25, 26, 27, 28 Hearst Corporation Building 71, 71 Hearst Ice Falls installation 71, 71 Heatherwick Studio 73 Herzog & de Meuron 6, 54, 56, 70, 99, 112, 120–121, 154 High Life Textile Factory 76 Hinman Building (Georgia Tech University) 37, 38, 39 Holl, Steven 39, 72, 150

249

Index

Holle, Heather 155 Holy Rosary Chapel 71 House in a Green Neighborhood 224, 228 House of 40 Knots 225–226, 229 House of Culture 205–206, 211 Höweler + Yoon 166, 168 hung assemblies 8, 11–12 Hyderabad housing project 212, 214 Hydrographic Studies building (Madrid) 137 i.active BIODYNAMIC cement 80 Imperial Hotel 198 infated cushions 17–18, 19 infated membranes 18–19, 22 Ini Ani cofee shop 68, 68 insitu casting see cast-in-place concrete Iranian weaving 223 Isler, Heinz 88, 127 Isosaki, Arato 19 Italcementi 80 jali 221 Japanese joinery 163–166 Jeanneret, Pierre 11–12 Jeferson, Tomas 200 Jérémie Kœmpgen Architecture 150 jigoku-gumi 165–166 Josephsohn, Hans 65 Kahn, Louis xxi Kalamazoo College 182 Kapoor, Anish 19 Kinetic Wall (Barkow Leibinger) 33 Kolumba Museum 221, 222, 223 Konzerthaus Blaibach 123, 123, 124, 124, 125 Koshino House 85–86 Kresge Auditorium (MIT) 131, 131, 132, 132 Kreysler Associates 163 Kukje Gallery (Seoul) 39–40, 41, 42, 42 Kuma, Kengo 18, 20, 28, 165, 198–200, 233–234 La Congiunta 65, 66, 67 Lafarge 77 laminated veneer lumber (LVL) 233–234, 235 Le Corbusier 11–12, 24–25, 98, 138–139 Lewerentz, Sigurd 207–209, 211 Lewis Tsuramaki Lewis 68 light see natural light light-transmitting concrete 74–75, 75, 76–77, 77 Lilas Pavilion (Serpentine Gallery) 12, 13 Lions Park Scout Hut 235, 235, 236 LiTraCon 76 Litracon 76 log cabins 182, 235, 235, 236 lost wax method 109–110 Louisiana State Museum and Sports Hall of Fame 66, 67, 68 Lubetkin, Berthold 62 Lucem 76 Lucerne Festival 19, 21, 22 Lucy Carpet House 185, 188 Madjabadi, Habibeh 226 Magma Architects 14, 16 Maillart, Robert 126–127 Maison de Verre 180, 180–181 Maison Hermes 181, 181, 182

250

Markli, Peter 65 Mashhadimirza, Alireza 223–224, 226 mashiyaba 223 masonry bricks 174–175 Matadero Warehouse 8B 185, 186 Matera, Italy 145, 147, 148 materials: alliances and xxi; behavior of xxiv; design and xx; elastic 24; environmental impact of 81; fexible 4, 30, 32; role of failure in understanding xxiii; selection of xxiv, xxv, 9, 24, 152–153, 187–189; three-dimensional removal of 154; two-dimensional removal of 154; see also carving materials; casting materials; rigid materials; stacked materials; stretched materials MATSYS 69 Media-TIC 6–7, 7, 9, 9, 18, 18 Messe Basel 54 metal casting: bronze panels 112–113; lost wax method 109–110; metal alloys 69; sand casting 109–110; surface texture and 112–114; using ice/ dry ice 111 metal panels: casting process 110; cast iron 70; corners and 52, 53; embossed 51; expanded 51, 54; in façades 54–55, 55, 112–113, 113, 114, 114, 115; surface texture 113 Milan Expo (2015) 80 milling 143, 154–156; see also carving; CNC milling MIT Chapel 175, 177 Monadnock Building (Chicago) 196, 196, 197, 197 monolithic buildings: apertures in 122; appearance of 139; carved components and 150, 158; carved space and 144–145; cast concrete and 63, 65, 86, 98–99, 121, 135, 138; cofers and 61; façade texture in 209; lightness in 231; light-transmitting 216, 219; pattern in 211–212; stacked assemblies as 171, 173, 185, 187, 191, 193, 205–206, 211, 214; stretched membranes and 4–5 Montreal Expo (1967) 8, 11 mothballing 40 Munich Olympics Complex (1972) 8, 8 Museum of the Civilizations of Europe and the Mediterranean (MuCEM) 77–78, 78, 79 Music Pavilion (Kassel, Germany) 10–11 Musmeci, Sergio 135 MVRDV 219 Naiju Community Center and Nursery School 87 Nakamura, Hiroshi 232 NAP Architects 232 natural light: acrylic rods and 73; apertures and 124; carving and 151, 158, 162; cast concrete and 85, 87, 124, 137; cast iron structure for 69; cast stone and 66; concrete screens and 79–80, 124; ETFE foils and 36; fabric panels and 8; façade screens and 14, 30; glass blocks and 71, 180; glass panels and 56; metal panels and 52, 54, 113; stacked façades and 219–220, 222–223; stretched membranes and 14 Nelson-Atkins Museum 72, 72 Nemesi Architects 80 Nervi, Pier Luigi 90–91 New Museum of Contemporary Art 51–52, 52, 53, 54 Ningbo Historic Museum 184, 184 Nishizawa, Ryue 87–88 nomadic tents 3, 4 Notre Dame du Haut (Ronchamp) 138, 138, 139, 139

Index

Ofce dA 37, 211 Ohel Jakob Synagogue 173, 173 Oliver, Stefan 230 Optical Glass House 232 Otto, Frei 4, 8, 10, 12, 33 Oya stone 198, 200 Palazzetto dello Sport (Rome) 90, 92, 93 Palazzo Italia 80, 80 Pantheon (Rome) 61–62, 62, 63 paraboloid structures 25, 127–128, 131–132 Paris Expo (1937) 11 Partisans Design Studio 161–162 pattern: apertures and 121–122; cast concrete and 98–99; concrete masonry units (CMU) and 178; cordwood masonry and 182; coursing of modules and 188–189; light and 230; metal panels and 54; reclaimed materials and 184–185; stacked assemblies and 205–207, 207, 208–210, 230, 230, 231; stretched assemblies and 3–6, 14, 33; wood carving and 151, 155–156, 162; ziggurat 105–106 Paul Smith (London) 70 Penguin Pool (London Zoo) 62, 65 perforated screens 221–223 Petra, Jordan 144, 145 Petroski, Henry xxiii Phillips Exeter Library xxi, xxii Phillips Pavilion (1958 Brussels Expo) 24–25, 25–26, 28 Piano, Renzo 158, 181 plaster 66, 68–69 plastic casting 73, 74 plastic sheets 6 pliability 33–34, 56, 217 pneumatic structures 18–19, 22 Polich Tallix 112 polishing 65, 69, 85, 97 Ponte del Basento 135, 135 Portugal Pavilion (Lisbon) 129, 129, 130, 130 power washing 100, 152 pozzolana 61 Prada Aoyama 56 precast concrete: air-purifying concrete in 80; composite assemblies and 25, 88–90; concrete blocks and 179; lightness/weight in 137; natural light and 137; quality and 88; steel cables and 25, 28; translucent 76–77; ultra-high­ performance concrete (UHPC) 78 precasting 81 Private House 158 Punta della Dogana Museum 86, 86, 112, 119 PVC fabric 5, 12, 14, 16–17, 19 P-Wall installation 69 reclaimed building materials 183–184, 184, 185, 185, 186 REX 56 Riccioti, Rudy 77 rigid materials: glass panels 56, 58; softness/fuidity in 51–52; in stretched assemblies 24–25, 27, 30, 31, 32; stretched metal assemblies 52, 53, 54–55, 55 Rock Sites of Cappadocia 143–144, 144 Rolex Learning Center 135–136, 136 Roman Empire 61–62 roof assemblies: Cocoon plastic in 25, 27; composite assemblies 25; fabric panels in 6, 14; fexible

membranes in 42, 44, 46–47; hung assemblies and 11–12; impact of heat and humidity on 27–28; lightness/weight in 42, 44, 46–48; stacked 191; stadium structures 24; stainlesssteel cables in 28; steel tensioned 27–29; stretched assemblies and 9; tiles 28–29, 30; veneer bricks in 203; waterproofng in 131–132; woven wood in 47 Rudolph, Paul 24–25, 27–28, 99, 152 Ruf, Tomas 120 Rural Studio 185–186, 235 Saarinen, Eero 131–132, 175 sagging 5, 11, 16, 24, 33, 224 SANAA 51, 52, 54, 135 sandblasting 65, 85 sand casting 109–110 sandstone 144, 173 San Pedro Church (Duranzo) 201, 204, 205 Sassi 145, 147, 148 Scarpa, Carlo 104–105, 107 Schaulager (Basel) 99, 101, 152 Sean Collier Memorial (MIT) 166–168, 168 SeARCH 148 Seed Cathedral 73, 73, 74 SelgasCano 33–34, 34 Serpentine Pavilion (2015) 33–34, 34 Serpentine Sackler Gallery (London) 44, 44, 45, 46, 46 SF MOMO 163, 163 Shanghai Expo (2010) 73 Shooting Galleries (2012 London Olympics) 14–15, 16, 17, 17 shou sugi ban treatment 161 shuttering 83 Signal Box 54 silicone rubber 49, 49, 50, 50, 51 Sinclair Knight Merz 14 6a Architects 70 Siza, Alvaro 129 Skidmore, Owings and Merrill 5 Snøhetta 42, 159, 161, 163 SO-IL 39–40 solar screening 6–7 Solomon Guggenheim Museum 62, 64 SOS Children’s Villages Lavezzorio Community Center 102 South Asian Human Rights Documentation Center 214, 215, 216 stacked assemblies: benefts of 191; component scale and 171; coursing module patterns in 188–189; design decisions and 193; dry stacked 191; experimentation and xxiv; failures/limitations in 193–195; fuidity in 200–202, 202, 203–205; inconsistencies in 194–195; Iranian weaving techniques in 223; lateral stability and height 196–205; light-transmitting 216–217, 217, 218, 218, 219, 222, 222, 223, 230; load-bearing 191, 193, 196–197; mass and lightness in 231–236, 238; materials used in 171–176, 178–182; module characteristics in 188–189; mortar application and 191, 207–209; pattern and texture in 205–207, 207, 208–212, 214, 230, 230, 231; porosity and lightness in 219–227; protective layers and 186; recycled building materials in 183–184, 184, 185, 185, 186, 186, 187; reinforcement of 197–200; requirements

251

Index

for 190–191; roofs and 191; rotated bricks in 220, 220, 221, 221; structural forces and 191; structural innovation in 234–235, 238; twomaterial systems 193–194, 194, 195; as veneer cladding 191–192 stacked materials: adobe bricks in 173–174, 190; atypical 183–187; clay roof tiles 183–185, 186, 187; clinker bricks in 175–176, 176; concrete blocks in 178, 178, 179; cordwood masonry in 182; glass blocks in 179–181, 219, 232; issues in selection of 187–189; laminated veneer lumber (LVL) 233–234; masonry bricks in 174–175; reclaimed 183–186; stone in 172–173, 198–200; thinnings in 235–236; wood blocks 236, 237, 238; wood in 182, 190, 223 steel cables: concrete precast panels and 25, 28; façade screens and 28–29, 29; hung assemblies and 11–12; roof assembly and 27–28; stretched assemblies and 8 Steilneset Memorial 36, 37 stepwells 144–145, 146 stif materials see rigid materials stone blocks 166–167, 172, 172, 173 stone façades 158–159, 159, 160, 198, 198, 199 Storefront Gallery (NYC) 39 St. Petri Church 207–208, 208, 209, 209, 210, 210, 211 stretched assemblies: building corners in 52; building scale 3–4; clinging/draping in 36–37, 39–40, 42; component scale 3–4; durability and 3; equilibrium and 24; experimentation and xxiv, 10; lightness/weight in 42, 44, 46–48; membrane construction in 3–4, 22–23; mothballing 40; nomadic tents and 3, 4; pliability/sagging in 33–34, 36; stadium roof structures and 24; structural frames for 3, 6, 8, 19, 31–34, 36, 44, 46–48, 54; temporary buildings and 3–4, 8–9, 24, 42, 44; see also fexible membranes; framed assemblies stretched assembly installation: framed assemblies 12–17; hung/suspended 8, 11–12; infated cushions 17–18; membrane tension in 10–11, 13; pneumatic structures 18–19, 22; prefabricated modules 14; steel cables in 8, 11; tension resistance in 10, 12 stretched materials: chainmail fabric 40, 42; elastic 24–25; ETFE foils 6–9, 9; experimentation and 10; fabric panels 4–6; fexible 30, 31, 32, 32; glass panels 56, 57, 58, 58; irregularly shaped frames and 34; rigid 24–25, 27–29, 51–52; selection of 9, 24; silicone rubber 49, 49, 50, 51 stretched metal assemblies: building corners in 52, 53; embossed metal façades in 54, 54; metal façade panels in 54–55, 55; metal mesh façades in 52, 53; softness/fuidity in 51–52 Structural Oscillations installation 201, 201 Studio Gang 102, 104, 182, 220 Studiomake 220 SunnyHills 165, 167 surface texture: brick assemblies and 211–212; bush hammering and 65, 85, 97, 99, 152; carving process and 150; casting framework and 65, 94, 98, 105–106, 106, 107, 114–115, 116, 117, 117, 118–119; cast metal panels and 112–114; as design feature 112–115, 117–119; digital fabrication and 117; granite in 123; light and shadow in 117–118; ornament in 120;

252

perforation patterns in 121–123; polishing and 65, 69, 85, 97; power washing and 100, 152; refning roughness of 119–124; releasing agents and 84–85; sandblasting and 65, 85; stretched assemblies and 51; wood carving and 150, 152, 156 suspended assemblies see hung assemblies Swiss Exposition (1939) 126 Swiss Federal Institute of Technology in Zurich (ETHZ) 201 Swiss Sound Box Pavilion 223, 223, 224 Tamedia Ofce Building 164, 164, 165, 165, 166 Tee Haus (Frankfurt) 18, 20, 21 Tefon (PTFE) 5, 7 temporary buildings 3–4, 8–9, 24, 42, 44 Temps Nouveau Pavilion (Paris) 11, 11, 12, 12 Tenara fabric 18–19 Tenerife Espacio de las Artes (TEA) 121–122, 122 tension: carving and 154; cast iron and 69; chainmail fabric and 42; concrete and 65, 84; concrete modules and 137; ETFE foils and 34; in fexible membranes 34, 36–37; in framed assemblies 12; heated plastic and 40; in pneumatic structures 18–19; in stacked wood assemblies 236, 238; steel cables and 25, 28; steel straps and 27; in stretched assemblies 10–12, 17, 24, 30, 32–33, 36–37, 39, 48 Teshima Art Museum 87–88, 88, 89 Terme Vals 148 thinnings 235–236 Tomas, Alexander 49 3D scanners 161 tires 185–186 Tod Williams Billie Tsien Architects 112 Tombasil 112 Tongxian Gatehouse 211, 212, 213, 214 Trahan Architects 66, 71 translucent concrete 76, 77 Treasury Building (Petra) 145 Trerrfellhytta Reindeer Viewing Pavilion 159–160, 160, 161, 161 Tubaloon (Kongsberg, Norway) 42, 43, 44, 46 TWA Terminal 132–133, 134 Twitchell, Ralph 24–25, 27–28 ultra-high-performance concrete (UHPC) 77–80 UNESCO World Heritage site 144 Unilever Haus (Hamburg) 34, 35, 36 Unite d’Habitation (Marseille) 98, 98, 99 Unity Temple 62, 64 Universidad Nacional Autonoma de Mexico (UNAM) 127 University of Virginia serpentine garden 200, 200, 201 Vakko Fashion Center 56, 58 Valetta Parliament House 158–159, 159, 160 Vander Ploeg, Evan 49 Venice Biennale (2014) 33 Ventura Virzi Arquitectos 232 Villa Solaire 150–151, 153 Villa Vals 148, 149, 150 Vitellozzi, Annibale 90 Voralberg Museum Addition 89, 90 Wandel Hoefer Lorch and Hirsch 173 Wapan masonry 184

Index

Watercube (Beijing National Aquatics Center) 17–18, 20 West, Mark 137 Wignall, Zachary 30, 32 wood blocks 236, 238 wood carving: 3D scanners and 161; apertures in 151, 155–156, 156, 157; assemblies 159–161, 161, 162; façades and 150–151, 158, 161; joinery and 163–166; surface texture and 150, 151, 152, 152, 156; warping in 152–153 wood components 182, 190–191, 235–236 wood doors 150, 151, 152 Wright, Frank Lloyd 62, 179, 198

Xenakis, Iannis 24–25 Yale University Arts and Architecture Building 99, 100, 152 Yancy Tire Chapel 185 Yoh, Shoei 87 Young Vic Teater 189, 189 Yusuhara Wooden Bridge Museum 233–234, 234, 235 Zaha Hadid Architects 12, 44 ziggurat patterns 105, 105, 106, 107 Zumthor, Peter 36, 114, 148, 221, 223 Zurman-Nasution, Anggita 193

253