Delivering on the Climate Emergency: Towards a Net Zero Carbon Built Environment 9811963703, 9789811963704

Table of contents :
Foreword
Preface
Acknowledgements
Contents
List of Figures
List of Tables
List of Boxes
1: The Climate Emergency and the Built Environment
1.1 The Climate Emergency
1.2 Carbon Emissions and the Built Environment
1.2.1 Climate Action in the Built Environment: Towards Net Zero Emissions
1.2.2 Green Building Council of Australia
1.2.3 Architecture 2030 Challenge
1.2.4 RIBA 2030 Challenge
1.2.5 LETI
1.2.6 C40 Challenge
1.2.7 GlobalABC Regional Roadmap for Buildings and Construction in Africa
1.2.8 IEA Roadmap for Energy-Efficient Buildings and Construction in ASEAN
1.3 Challenges and Gaps in Achieving Net Zero Carbon in the Built Environment
1.3.1 Increasing Global Construction
1.3.2 Urban Heating and the Growing Demand for Cooling
1.3.3 Lack of Building Codes, Policy and Regulation
1.3.4 Upgrading and Retrofitting Existing Buildings
1.3.5 Education and Training
1.4 Summary and Upcoming Chapters
References
2: Operational Carbon in the Built Environment: Measurements, Benchmarks and Pathways to Net Zero
2.1 Measuring Operational Energy and Carbon
2.1.1 Benchmarking and Normalisation Factors
2.1.2 Building Performance Ratings
2.1.3 Building Performance Assessment Tools
2.1.4 Post-occupancy Evaluation
2.2 Factors Impacting Operational Carbon Benchmarks
2.2.1 Overview of Factors
2.2.2 Overview of Factors: Australian Context
2.3 Comparison of Published Benchmarks and Targets
2.3.1 The Current State of Operational Energy and Carbon in Australia
2.3.2 Global Targets
2.3.3 Australian Targets
2.4 Strategies to Reduce Operational Carbon
2.4.1 Energy-Efficient Design: New Build and Retrofit
New Build Design Strategies
Retrofit Design Strategies
2.4.2 Energy Generation
2.5 Towards Net Zero Operational Carbon
References
3: Embodied Carbon in the Built Environment: Measurements, Benchmarks and Pathways to Net Zero
3.1 The History of Measuring Embodied Carbon
3.2 Factors Impacting Embodied Carbon Benchmarks
3.2.1 Functional Unit Area Definition: Estimated Impact on Embodied Carbon Measurement of 12–30%
3.2.2 Building Classification: Estimated Impact on Embodied Carbon Measurement of up to 100%
3.2.3 Methodology for Life Cycle Inventory (LCI) Coefficients: Estimated Impact on Embodied Carbon Measurement of between 2 and 99%
3.2.4 Building-Scale Lifecycle Carbon Methodology: Estimated Impact on Embodied Carbon Measurement of up to 77%
3.2.5 Completeness or Scope of Items Included: Estimated Impact on Embodied Carbon of up to 50%
3.2.6 Geographic Context: Estimated Impact on Embodied Carbon of 30% or More
3.2.7 Case Study Example: Clay Brick
3.3 Existing Embodied Carbon Benchmarks
3.4 Strategies to Reduce Embodied Carbon
3.4.1 Design Strategy 1: Building Nothing/Adaptive Reuse
3.4.2 Design Strategy 2: Optimise and Dematerialise
3.4.3 Design Strategy 3: Smart Design
3.4.4 Design Strategy 4: Low Carbon Supply Chain
3.5 Net Zero Embodied Carbon
References
4: Delivering a Net Zero Carbon-Built Environment: Synthesis, Measurability, Targets and Reporting
4.1 Methods Used to Determine Climate Emergency Targets
4.1.1 Methods Used to Determine Operational Carbon Targets
Top-Down Method: Paris Proof
Bottom-Up Method
Combined Method to Determine Climate Emergency Targets
4.1.2 Methods Used to Determine Embodied Carbon Targets
4.2 Climate Emergency Targets
4.2.1 Climate Emergency Targets for Operational Carbon Emissions
4.2.2 Climate Emergency Targets for Embodied Carbon Emissions
4.3 Net Zero Whole Life Carbon Pathway
4.3.1 Comparing and Combining Operational and Embodied Data
Step 1: Convert GFA to the Floor Area Defined in the Embodied Carbon Functional Unit
Step 2: Convert Electricity to Carbon Dioxide Equivalent (CO2e)
Example: An Office Building in Sydney
Limitations
4.3.2 Implementation and Reporting of the Pathway
References
5: Case studies: Exemplars to Learn From
5.1 Exemplar Buildings
5.1.1 New Buildings—Residential
Design and Performance Profile
Design Intentions
Performance and Pathway to Net Zero
Case Study Information Source
Design and Performance Profile
Design Intentions
Performance and Pathway to Net Zero
Case Study Information Source
Design and Performance Profile
Design Intentions
Performance and Pathway to Net Zero
Case Study Information Source
Design and Performance Profile
Design Intentions
Performance and Pathway to Net Zero
Case Study Information Source
5.1.2 New Buildings—Non-residential
Design and Performance Profile
Design Intentions
Performance and Pathway to Net Zero
Case Study Information Source
Design and Performance Profile
Design Intentions
Performance and Pathway to Net Zero
Case Study Information Source
Design and Performance Profile
Design Intentions
Performance and Pathway to Net Zero
Case Study Information Source
5.2 Exemplar Precincts
5.2.1 New Precincts
Design and Performance Profile
Design Intentions
Performance and Pathway to Net Zero
Case Study Information Source
Design and Performance Profile
Design Intentions
Performance and Pathway to Net Zero
Case Study Information Source
5.3 Exemplars in Embodied Carbon Reduction
5.3.1 New Buildings
Design and Performance Profile
Design Intentions
Performance and Pathway to Net Zero
Case Study Information Source
5.3.2 New Precincts
Design Intentions
Design and Performance Profile
Net Zero Carbon Exemplars—Challenges and Opportunities
References
6: Policy Pathways to a Net Zero Carbon-Built Environment
6.1 Australia’s Zero Carbon Policy
6.1.1 Australia’s National Targets, Policies and Programs
6.1.2 State and Territory Governments’ Objectives and Action Plans
6.1.3 Local Government Initiatives
6.1.4 Mandatory and Voluntary Approaches to Reducing Operational and Embodied Energy Demand and Increasing the Use of Renewable Energy
Mandatory Approaches
Non-mandatory or Voluntary Approaches
Voluntary Rating Systems
Voluntary Government Programmes
Incentive Schemes
Industry-Led Initiatives
6.1.5 Australian Zero Carbon Policy Nexus
6.2 International Policies, Standards and Initiatives
6.2.1 International Mandatory and Voluntary Standards and Policies
6.2.2 Mandatory Standards for the Embodied Carbon of Buildings
6.2.3 Leading Groups and Initiatives Worldwide
6.3 Opportunities and Challenges of Existing Zero Carbon Policies
6.4 The Evolution of Zero Carbon Policies
References
7: Conclusions and Recommendations: Envisioning a Net Zero Carbon Future in the Built Environment
7.1 Concluding Remarks
7.2 Recommendations for Future Directions
References
Index

Citation preview

Delivering on the Climate Emergency Towards a Net Zero Carbon Built Environment deo pr a s a d ay su k u ru ph i l i p ol df i e l d l a n di ng m a l ay dav e c a rol i n e nol l e r b ao j i e h e

Delivering on the Climate Emergency “This book provides much needed insights into the scale and nature of the challenges we all face in reducing the impact of built environments on our shared climate. It plots safer pathways forward for reducing operational and embodied energy in construction and refurbishment, starting with reducing the need for heating and cooling energy in the first place. All we need now is for politicians and society to understand the urgency of understanding and following its advice. It should be mandatory reading for all designers, planners and developers in Australia.” —Sue Roaf, Emeritus Professor of Architectural Engineering at Heriot Watt University, Scotland, UK “The Net Zero Carbon Guide is a remarkably complete and lucid survey of issues related to the Australian commercial and residential building stock, especially aspects related to embodied energy and emissions. Students or specialists who need to augment their knowledge (or be reminded about things they have forgotten) will find the book especially valuable.” —Nils Larsson, FRAIC, Executive Director, iiSBE, Canada “It has become very clear from most scientific works, especially the latest IPCC reports that the urgency of climate change is upon us. Urgent action, especially with milestones like 2030, will help meet the challenges. The built environment (buildings and cities are a major contributor) and this book shows how, using science-based approaches, we can deliver on net zero carbon new buildings by 2030 and for existing ones we can do this by 2040. We need a whole of life and whole building approach. I think this book can be used in many countries and even localised with local data and benchmarks. Great publication.” —Professor Wu.Jiang, Chairman, Asia Architecture Association, Fellow, Academie d’Architecture, Dean, UNEP-TONGJI Institute of Environment for Sustainable Development., China “Delivering on the Climate Emergency’ provides a breadth of information, methods and targets, relating to achieving a zero carbon built environment, covering both operational energy and embodied carbon, covering new build and retrofit. Although specifically targeted for an Australian audience, it has global relevance and provides an excellent source of reference for education, practice and all those interested in our future built environment.” —Professor Phil Jones OBE, Cardiff School of Architecture, Wales, UK

Deo Prasad • Aysu Kuru Philip Oldfield • Lan Ding Malay Dave • Caroline Noller Baojie He

Delivering on the Climate Emergency Towards a Net Zero Carbon Built Environment

Deo Prasad School of Built Environment UNSW Sydney Kensington, NSW, Australia Philip Oldfield School of Built Environment UNSW Sydney Kensington, NSW, Australia Malay Dave Steensen Varming Sydney, NSW, Australia Baojie He School of Architecture and Urban Planning Chongqing University Chongqing, China

Aysu Kuru School of Architecture, Design and Planning University of Sydney Camperdown, NSW, Australia Lan Ding School of Built Environment UNSW Sydney Kensington, NSW, Australia Caroline Noller The Footprint Company Randwick, NSW, Australia

ISBN 978-981-19-6370-4    ISBN 978-981-19-6371-1 (eBook) https://doi.org/10.1007/978-981-19-6371-1 © The Editor(s) (if applicable) and The Author(s), under exclusive licence to Springer Nature Singapore Pte Ltd. 2022 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors, and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Palgrave Macmillan imprint is published by the registered company Springer Nature Singapore Pte Ltd. The registered company address is: 152 Beach Road, #21-01/04 Gateway East, Singapore 189721, Singapore

Foreword

There is considerable global attention focussed on the pathways to net zero carbon. COP#26 in Glasgow has highlighted what has been known for years—there is an urgent need to reduce carbon emissions globally and that the built environment is a key opportunity sector. The IPCC Report (2021) labelled ‘Code Red’ has further highlighted notions of climate emergency. This book is well timed to bring together science-­ based evidence on how the built environment can navigate urgently towards a net zero carbon future. It builds on past work on strategies for sustainable low carbon design, and the increasing cost-effectiveness of both on-site and off-site renewable energy, and places it in the context of ‘climate emergency’ thinking to engage built environment professionals in easy-to-use guidance towards net zero. It takes a whole-of-life approach and includes both operational and embodied carbon in its guidance. It draws on Australian climate data but has global applicability. It acknowledges a myriad of roadmaps and pathways flagged by global and local agencies from the UN Global Alliance for Building and Construction to the World Green Building Council, the Royal Institute of British Architects, Architecture 2030 and the Australian Institute of Architects’ Climate Action and Sustainability Taskforce (CAST) Group. The book is a partner document to the accompanying shorter version— the guide, ‘Race to Net Zero Carbon’, specifically for Australian v

vi Foreword

audiences. This book goes into some depth on design strategies, systems and exemplars from around the world, policy snapshots from various countries, and developing benchmarks and targets for delivering on net zero carbon buildings globally. A key element of this book is an ‘architect–client’ conversation on trade-offs on when and how net zero carbon will be delivered for that building. The architect may use all the tools at their disposal to bring out ‘best performance’ at design time for both new and refurbished buildings. They could also explore on-site or off-site renewable energy and may find photovoltaics a more economic option. In doing so, the matter of on-site generation and outsourcing renewables should be discussed and a timeline set for achieving net zero for all buildings. This is a very positive and inclusive approach. This book is among the legacy projects of the Cooperative Research Centre for Low Carbon Living (CRCLCL), which I had the pleasure of chairing. The CRCLCL (www.lowcarbonlivingcrc.com.au) was a collaboration of a number of Australian industries, governments and researchers. It showed that when collaborations at such a scale happen, Australian researchers and industry can deliver on practical outcomes and impacts. The CRCLCL developed a significant evidence base for low carbon living policies, knowledge for communities, tools and technologies for the market, and world-class capacity building. These all helped capture economic and social opportunities for Australia. This project built on past projects of the CRCLCL and was led by researchers from the University of New South Wales (UNSW), Sydney. They partnered with the Australian Institute of Architects’ CAST Group and other built environment stakeholders to produce this book and guide for all built environment professions. Chair of the Board of the CRC for Low Carbon Living (2012–2019) Hon Robert Hill AC 

Preface

Climate change has been recognised for some time now, but over time with more research and evidence it has become clearer that its implications for planet Earth and all that inhabit it are much more serious than originally thought. In fact, the latest IPCC Report (2021) labelled ‘Code Red’ points out quite clearly how urgent it is to deal with both mitigation at scale and adaptation. This is evident nowhere more than in the built environment—the buildings and cities we live in. As the urban population increases rapidly, the matter of what and how we build is drawing a lot of attention because it is not only a significant contributor to climate change, but also shows the best opportunities for leading the mitigation and adaptation charge. The Glasgow COP#26 has shown significant political ability to act on the ‘climate emergency’, though not enough for many and not quick enough for most. The 2050–2060 goals show considerable commitment, but to keep temperature increases to within 1.5°C will require meaningful 2030 targets. The built environment has been proactive in getting its sector motivated with knowledge, technologies and techniques to deliver change towards net zero carbon 2030; this has largely been ‘bottom-up’, driven by professional champions, leading industry and forward-­thinking governments.

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There has been a history of built environment sector awareness of sustainable design and planning, ecological impacts of design decisions, and the comfort and well-being benefits of sustainably designed buildings. There are now many tools and reasonable benchmarks and pathway documents to drive net zero carbon buildings and precincts in most countries. Most leading institutions are now embedding these in their teaching and learning programs, and there are materials, technologies and techniques available to guide net zero carbon outcomes. The challenge is to move past one-off cases to mainstreaming the use of all the levers available to drive change. These include advanced, researched knowledge, practical design approaches to best performance exemplars that illustrate success, and technology familiarity with construction codes that push best performance rather than simply eliminating worst practice. These changes should be led by governments who ensure all public buildings are net zero carbon, provide subsidies and rebates to mainstream key technologies, and use all the available evidence to develop policies that focus on short-term delivery of net zero carbon buildings. These changes would provide opportunities to create markets for new products and technologies that benefit the economy. This book aims to provide in-depth knowledge on how the sector can rapidly move towards net zero carbon buildings in the short term. It uses science-based evidence and analytics that goes beyond the aspirational. It is our aim that this book remains a deep dive technical support to each country preparing their own guide based on detailed local data from which local benchmarks, targets and pathways can be determined. A prototype of this guide is available to draw from at www.lowcarbonlivingcrc.com.au/. The authors can assist in developing national guides based on local climates, practices and economics. In this book we strongly recommend alignment and consistency in approach to knowledge and engagement, including methodologies in measurement, to bring about market transformation towards net zero carbon buildings. Historically most professionals have either focussed on operational energy/carbon or embodied energy/carbon, and in most cases these two groups have not adequately collaborated to view the whole building over its entire lifecycle. In most cases, the focus has been on the operational life of the building, which does not consider a significant component of

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lifecycle carbon. This book takes a whole-of-life and all-of-carbon approach to its guidance. Several chapters take a deep dive on this approach. These are then synthesised to illustrate how best to drive down carbon through a holistic approach, with a particular focus in this sense on the Australian situation. A chapter on international case studies illustrates how certain exemplar buildings have used the knowledge, tools and design to deliver their best buildings and, in most cases, how they perform post occupancy. The other key lever driving down carbon in buildings is a top-down approach where governments can—through future-thinking policies, regulations and codes—mandate or incentivise change. Across the book there are three key tiers of action: 1. Good design and best performance through energy efficiency and careful material selection on-site. This uses readily available knowledge on efficient design principles (climate appropriate) to get the overall form, façade and planning right—essential for laying the foundations for net zero carbon outcomes. Low embodied carbon materials and systems are used in all stages. High-quality design tools are used to determine energy loads, and the best performance technologies and systems to meet those loads are also determined. Well-­ designed procurement methods are important in this process. Design integration is also critical to ensure best outcomes. 2. By using the above approach, well-designed outcomes are ensured. However, there may still be a shortfall in both embodied and operational carbon. As part of an integrated design, it is imperative to explore on-site generation of energy. This is mostly in the form of building-integrated photovoltaics. Battery storage may be needed in some building types in some climates and should be considered. 3. Having integrated the above two tiers of action, there may still remain a gap between best performance and the net zero whole-of-life carbon goal. At this point it is important to consider off-site renewables (ensuring they are from well-approved and accredited sources). These actions work best with an all-electric building as other fuel forms, including gas, will not be good options due both to their carbon

x Preface

and cost factors. Overall, what is most important is the CLIENT– DESIGNER conversation. The design and the designer should lead the conversation on what best performance looks like against what may be local benchmarks and best practice for that building type in that climate. The conversation needs to explore the client’s appetite for investing in each of the three stages above—design and technology integration, on-­ site generation and off-site offsets. With these in mind, a clear direction is needed in terms of the timeline for net zero operational carbon by 2030 and net zero embodied carbon for 2040 for each and every project—new or refurbishment. This approach does not force additional costs on buildings, but the conversation helps to find the best investment approach to net zero carbon given the increasing client appetite for a cleaner and more sustainable future for all. UNSW Sydney, Australia University of Sydney, Australia  UNSW Sydney, Australia  UNSW Sydney, Australia  Steensen Varming, Australia  The Footprint Company, Australia  Chongqing University, China 

Deo Prasad Aysu Kuru Philip Oldfield Lan Ding Malay Dave Caroline Noller Baojie He

Acknowledgements

The research underpinning this book is funded by the CRC for Low Carbon Living Ltd supported by the Cooperative Research Centres program, an Australian Government initiative. This book was part of the CRC for Low Carbon Living (CRCLCL) post-CRC phase funding managed by the Low Carbon Institute. The UNSW School of Built Environment provided further financial assistance to support this book. We would like to thank our industry advisors Lester Partridge of LCI, Ian Dixon of GHD and Caroline Pidcock of Pidcock Architects for their input. The contents of this book and its performance benchmarks and targets drew upon the data and feedback provided by the National Australian Built Environment Rating System, the Footprint Company, Australian Architects Declare Climate & Biodiversity Emergency, Green Building Council of Australia, Australian Sustainable Built Environment Council and CSIRO. This book benefited from the review, support and guidance of the Australian Institute of Architects’ Climate Action and Sustainability Taskforce (CAST) Group. It has drawn from numerous publications produced at a time which led to COP#26 in Glasgow—a milestone event for all nations treating the climate emergency seriously and the supporting sciences which highlight the threats to our planet and its life forms. We would also like to thank Dr William Craft, Dr John Blair and Ms Sara Jinga specifically, for their technical support and input. xi

Contents

1 The  Climate Emergency and the Built Environment  1 1.1 The Climate Emergency   1 1.2 Carbon Emissions and the Built Environment   5 1.2.1 Climate Action in the Built Environment: Towards Net Zero Emissions   8 1.2.2 Green Building Council of Australia  13 1.2.3 Architecture 2030 Challenge  13 1.2.4 RIBA 2030 Challenge  13 1.2.5 LETI  14 1.2.6 C40 Challenge  15 1.2.7 GlobalABC Regional Roadmap for Buildings and Construction in Africa  15 1.2.8 IEA Roadmap for Energy-Efficient Buildings and Construction in ASEAN  16 1.3 Challenges and Gaps in Achieving Net Zero Carbon in the Built Environment  17 1.3.1 Increasing Global Construction  17 1.3.2 Urban Heating and the Growing Demand for Cooling 18 1.3.3 Lack of Building Codes, Policy and Regulation  19

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1.3.4 Upgrading and Retrofitting Existing Buildings  20 1.3.5 Education and Training  21 1.4 Summary and Upcoming Chapters  22 References 23 2 Operational  Carbon in the Built Environment: Measurements, Benchmarks and Pathways to Net Zero 29 2.1 Measuring Operational Energy and Carbon  29 2.1.1 Benchmarking and Normalisation Factors  29 2.1.2 Building Performance Ratings  33 2.1.3 Building Performance Assessment Tools  34 2.1.4 Post-occupancy Evaluation  37 2.2 Factors Impacting Operational Carbon Benchmarks  38 2.2.1 Overview of Factors  38 2.2.2 Overview of Factors: Australian Context  39 2.3 Comparison of Published Benchmarks and Targets  42 2.3.1 The Current State of Operational Energy and Carbon in Australia  42 2.3.2 Global Targets  55 2.3.3 Australian Targets  57 2.4 Strategies to Reduce Operational Carbon  60 2.4.1 Energy-Efficient Design: New Build and Retrofit  60 2.4.2 Energy Generation  69 2.5 Towards Net Zero Operational Carbon  72 References 74 3 Embodied  Carbon in the Built Environment: Measurements, Benchmarks and Pathways to Net Zero 79 3.1 The History of Measuring Embodied Carbon  79 3.2 Factors Impacting Embodied Carbon Benchmarks  81 3.2.1 Functional Unit Area Definition: Estimated Impact on Embodied Carbon Measurement of 12–30% 84 3.2.2 Building Classification: Estimated Impact on Embodied Carbon Measurement of up to 100%  84

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3.2.3 Methodology for Life Cycle Inventory (LCI) Coefficients: Estimated Impact on Embodied Carbon Measurement of between 2 and 99%  85 3.2.4 Building-Scale Lifecycle Carbon Methodology: Estimated Impact on Embodied Carbon Measurement of up to 77%  86 3.2.5 Completeness or Scope of Items Included: Estimated Impact on Embodied Carbon of up to 50%  88 3.2.6 Geographic Context: Estimated Impact on Embodied Carbon of 30% or More  88 3.2.7 Case Study Example: Clay Brick  89 3.3 Existing Embodied Carbon Benchmarks  92 3.4 Strategies to Reduce Embodied Carbon 103 3.4.1 Design Strategy 1: Building Nothing/Adaptive Reuse103 3.4.2 Design Strategy 2: Optimise and Dematerialise 107 3.4.3 Design Strategy 3: Smart Design 108 3.4.4 Design Strategy 4: Low Carbon Supply Chain 108 3.5 Net Zero Embodied Carbon 108 References113 4 Delivering  a Net Zero Carbon-Built Environment: Synthesis, Measurability, Targets and Reporting119 4.1 Methods Used to Determine Climate Emergency Targets 119 4.1.1 Methods Used to Determine Operational Carbon Targets 119 4.1.2 Methods Used to Determine Embodied Carbon Targets 124 4.2 Climate Emergency Targets 127 4.2.1 Climate Emergency Targets for Operational Carbon Emissions 127 4.2.2 Climate Emergency Targets for Embodied Carbon Emissions 129

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4.3 Net Zero Whole Life Carbon Pathway 133 4.3.1 Comparing and Combining Operational and Embodied Data 135 4.3.2 Implementation and Reporting of the Pathway 137 References140 5 Case  studies: Exemplars to Learn From143 5.1 Exemplar Buildings 144 5.1.1 New Buildings—Residential 144 5.1.2 New Buildings—Non-residential  163 5.2 Exemplar Precincts 176 5.2.1 New Precincts 176 5.3 Exemplars in Embodied Carbon Reduction 187 5.3.1 New Buildings 187 5.3.2 New Precincts 193 References198 6 Policy  Pathways to a Net Zero Carbon-­Built Environment201 6.1 Australia’s Zero Carbon Policy 201 6.1.1 Australia’s National Targets, Policies and Programs201 6.1.2 State and Territory Governments’ Objectives and Action Plans 206 6.1.3 Local Government Initiatives 210 6.1.4 Mandatory and Voluntary Approaches to Reducing Operational and Embodied Energy Demand and Increasing the Use of Renewable Energy212 6.1.5 Australian Zero Carbon Policy Nexus 218 6.2 International Policies, Standards and Initiatives 223 6.2.1 International Mandatory and Voluntary Standards and Policies 223 6.2.2 Mandatory Standards for the Embodied Carbon of Buildings 225 6.2.3 Leading Groups and Initiatives Worldwide 227

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6.3 Opportunities and Challenges of Existing Zero Carbon Policies 229 6.4 The Evolution of Zero Carbon Policies 231 References232 7 Conclusions  and Recommendations: Envisioning a Net Zero Carbon Future in the Built Environment235 7.1 Concluding Remarks 235 7.2 Recommendations for Future Directions 238 References240 I ndex241

List of Figures

Fig. 1.1 Fig. 1.2 Fig. 1.3

Fig. 1.4 Fig. 1.5 Fig. 1.6 Fig. 2.1

Climate-influenced disasters and extreme weather events, 2012–2021 (Source: data from NOAA 2020) 2 Global greenhouse gas emissions and warming scenarios (Ritchie and Roser 2022—Image CC-BY) 4 Building and construction’s share of global energy-related greenhouse gas emissions, 2020 (UNEP 2021; IEA 2021a). ‘Buildings construction industry’ is the portion (estimated) of overall industry devoted to manufacturing building construction materials such as steel, cement and glass. Indirect emissions are emissions from power generation for electricity and commercial heat. (Source: IEA 2021a. All rights reserved. Adapted from ‘Tracking Clean Energy Progress’)6 Scope of carbon emissions across the different stages of a building lifecycle (by authors) 8 Strategies to achieve net zero whole life carbon buildings (by authors) 10 Percentage of zero carbon ready buildings needed in the total building stock, 2020–2050 (Source: by authors, with data from IEA 2021b) 11 Green building rating tool categories. (Source: Redrawn based on Illankoon et al. 2019; Note: Some countries or regions are running several types of green building rating xix

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List of Figures

schemes. Various refers to various types of new and existing buildings such as single-family residential, multi-residential housing, residential complex, office, school, retail, hotel, home and others) 34 Fig. 2.2 Evolution of POE levels and the steps to conduct POE. (Source: Authors) 38 Fig. 2.3 Key variables determining operational carbon benchmarks. (Source: Authors) 39 Fig. 2.4 Eight climate zones across Australia. (Source: ABCB 2019; Image credit: Creative Commons Attribution-No Derivatives—4.0 International Licence https://creativecommons.org/licenses/by-­nd/4.0/ © Commonwealth of Australia and the States and Territories of Australia 2019, published by the Australian Building Codes Board) 41 Fig. 2.5 Percentage of total emissions (MtCO2e) by building type and energy source in 2013. (Source: ASBEC 2016) 44 Fig. 2.6 Electricity demand of Australia and states in 1999–2020. (Source: Author-­drawn based on AER 2021) 44 Fig. 2.7 Annual renewable energy generation and percentage variations. (Source: Author-drawn based on the Clean Energy Council 2021) 45 Fig. 2.8 The average star level of commercial office buildings in Australia. (Source: NABERS 2020b) 47 Fig. 2.9 Carbon emissions of commercial office buildings according to base, tenancy and whole buildings (Conservative scenario: 4.5 stars; aspirational scenario: 5.5–6 stars). (Source: Authorcalculated based on the databases of NABERS and the CBD program)48 Fig. 2.10 Operational carbon emission intensity of commercial office base buildings across different states. (Source: Authorcalculated based on the databases of NABERS and the CBD program)49 Fig. 2.11 Operational carbon emissions of commercial office tenancy buildings across different states. (Source: Author-calculated based on the databases of NABERS and the CBD program) 50 Fig. 2.12 Operational carbon emissions of commercial office whole buildings across different states. (Source: Author-calculated based on the databases of NABERS and the CBD program) 50

  List of Figures 

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Fig. 2.13 Operational carbon emissions of commercial office base buildings in NSW according to climate zones. (Source: Author-calculated based on the databases of NABERS and the CBD program) 51 Fig. 2.14 The reduction in the carbon emission intensity of commercial office buildings. (Source: Author-calculated based on the databases of NABERS and the CBD program) 52 Fig. 2.15 Operational carbon emissions for retail buildings in Australia. (Source: Author-calculated based on the databases of NABERS and the CBD program) 53 Fig. 2.16 Carbon emission intensity of retail buildings across different states. (Source: Author-calculated based on the databases of NABERS and the CBD program) 54 Fig. 2.17 Carbon emission intensity of residential buildings across different states. (Source: Author-calculated based on the databases of NatHERS and the CBD program) 55 Fig. 2.18 An overview of strategies to reduce operational carbon. (Source: Authors) 60 Fig. 2.19 Energy-efficient strategies for demand reduction. (Source: Authors)61 Fig. 2.20 Energy generation and carbon offset for increased supply. (Source: Authors) 69 Fig. 2.21 Commercial and residential buildings’ energy efficiency and generation to achieve net zero operational carbon emissions (Source: BZE, 2014) 73 Fig. 3.1 Comparison of embodied carbon per kg of brick (kgCO2-e/ kg) (by authors) 90 Fig. 3.2 Comparison of embodied carbon of 1 m2of brick wall (kgCO2-e) A1–A3. (Note: Technically, The Footprint Calculator/EPiC and IE Lab are A1–A5 due to the underlying HA/EIO method completeness (by authors)) 90 Fig. 3.3 Comparison of embodied carbon of brickwork in a typical house (kgCO2-­e) (by authors) 92 Fig. 3.4 Comparison of published embodied carbon benchmarks for Class 1 and 2 buildings (detached residential and apartments). (Sources: The Footprint Company; Carre 2011; Carre and Crossin 2015; GBCA and Thinkstep 2021; Schmidt et al. 2020; Robati et al. 2021; Röck and Sørensen 2022; Simonen et al. 2017; Pasanen and Castro 2019; LETI 2020b) 98

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Fig. 3.5

Fig. 3.6

Fig. 3.7

Fig. 3.8 Fig. 3.9

Fig. 4.1 Fig. 4.2 Fig. 4.3 Fig. 4.4 Fig. 4.5 Fig. 4.6 Fig. 4.7 Fig. 4.8 Fig. 4.9 Fig. 5.1

List of Figures

Comparison of published embodied carbon benchmarks for Class 5 and 6 buildings (office and retail). (Sources: The Footprint Company; Pasanen and Castro 2019; GBCA and Thinkstep 2021; Röck and Sørensen 2022; Simonen et al. 2017; LETI 2020b) Diagram outlining strategies for reducing embodied carbon at different points in the design process, along with their potential percentage reductions. The top line also suggests different embodied carbon calculation methods for these different stages (by authors) Comparison of whole lifecycle carbon emissions of ‘demolish and new build’ versus ‘deep refurbishment’. In this scenario, it is assumed the new build has a slightly higher energy efficiency than the deep retrofit, hence the retrofit curve is slightly steeper (by authors) International House, Sydney. A seven storey commercial building constructed of engineered timber (Ben Guthrie, The Guthrie Project) The net zero embodied carbon concept. It is vital that emissions are reduced as much as possible through reuse, optimisation, recycled materials and the supply chain before any residual emissions are offset (by authors) The top-down and bottom-up methods used to determine future carbon targets for buildings. (Source: Authors) The Paris Proof method adapted to Australian context. (Source: Authors) Steps of the top-down approach. (Source: Authors) Steps of the bottom-up approach. (Source: Authors) Method of generating EUI targets. (Source: Authors) Typical embodied carbon values in Australian buildings (kgCO2e/m2 NLA). Scope of A1–A5. (Source: Authors) Proposed approach to interim embodied carbon targets. (Source: Authors) Method for benchmarking and comparing embodied carbon figures. (Source: Authors) Net zero whole life carbon pathway. (Source: Authors) ZEB Pilot House. (Image copyright agreements provided by Snøhetta / Paal-André Schwital)

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106 111

112 120 121 121 124 125 130 130 132 133 145

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Fig. 5.2

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The subtle interiors of ZEB Pilot House presenting the use of natural materials such as timber, bricks and wood. (Image copyright agreements provided by Snøhetta / Paal-André Schwital)146 Fig. 5.3 (a) The outdoor atrium, (b) indoor living areas and (c) the landscape, all providing a comfortable feeling of cabin life in one of the world’s most performance-­wise advanced family houses. (Image copyright agreements provided by Snøhetta / Paal-André Schwital) 148 Fig. 5.4 Asquith PassivHaus. (Image copyright agreements provided by Chris Nunn) 149 Fig. 5.5 Asquith PassivHaus under construction. (Image copyright agreements provided by Chris Nunn) 151 Fig. 5.6. (a) Asquith PassivHaus; (b) its construction process which incorporates Australian-made sustainable timber wall and roof cladding CarbonLite, manufactured in Melbourne, and (c) the mechanical ventilation system with heat recovery for maximised efficiency and performance. (Image copyright agreements provided by Chris Nunn) 153 Fig. 5.7 Nightingale 2.0, designed by Six Degrees Architects and delivered in collaboration between HIP V. HYPE and Six Degrees Architects in accordance with the Nightingale Housing Values. Photographer Tess Kell. Nightingale 2.0. (Image copyright agreements provided by Six Degrees Architects and Simon O’Brien) 154 Fig. 5.8 Nightingale 2.0 Apartments’ common roof terrace for its residents. (Image copyright agreements provided by Six Degrees Architects and Simon O’Brien. Nightingale 2.0, designed by Six Degrees Architects and delivered in collaboration between HIP V. HYPE and Six Degrees Architects in accordance with the Nightingale Housing Values. Photographer Tess Kell) 155 Fig. 5.9 Nightingale 2.0’s energy performance (by Authors). (Adopted from Moore and Doyon 2018) 157 Fig. 5.10 Nightingale 2.0’s (a) shared communal spaces, (b) apartment interior and (c) initial design sketches. (Image copyright agreements provided by Six Degrees Architects and Simon O’Brien. Nightingale 2.0, designed by Six Degrees Architects

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Fig. 5.11 Fig. 5.12

Fig. 5.13

Fig. 5.14 Fig. 5.15 Fig. 5.16 Fig. 5.17 Fig. 5.18

Fig. 5.19

Fig. 5.20

List of Figures

and delivered in collaboration between HIP V. HYPE and Six Degrees Architects in accordance with the Nightingale Housing Values. Photographer Tess Kell) 158 Gillies Hall. (Image copyright agreements provided by Jackson Clements Burrows Architects and Peter Clarke) 159 Common spaces and the games room in Gillies Hall, showcasing its minimalist design and friendly environment. (Image copyright agreements provided by Jackson Clements Burrows Architects and Peter Clarke) 160 (a) The residential areas and (b) shared kitchen spaces in Gillies Hall displaying the use of natural materials and simplicity in its interior design. (Image copyright agreements provided by Jackson Clements Burrows Architects and Peter Clarke)162 CIC Zero Carbon Park. (Image copyright agreements provided by Ronald Lu & Partners) 163 (a) PV array covering the entire roof area. (b) View of CIC Zero Carbon Park overlooking the courtyard. (Image copyright agreements provided by Ronald Lu & Partners) 165 CIC Zero Carbon Park’s energy performance (by Authors) 167 (a) Kingspan Lighthouse and (b) its rooftop. (Image copyright agreements provided by Hufton+ Crow—Nick Hufton) 168 Kingspan Lighthouse has a window-to-wall ratio of 18%, as opposed to 25–30% in traditional houses, which has driven the integration of living spaces on the first floor with abundant daylight received through the skylights. (Image copyright agreements provided by Hufton+Crow—Nick Hufton)170 (a) Low carbon timber cladding on the exterior brings a natural aesthetic to the house. (b) The transparent chimney on top of the staircase creates an elegant lightwell bringing natural daylight into the lower levels of the building. (c) The rooftop of the house is covered with a PV array. (Image copyright agreements provided by Hufton+Crow—Nick Hufton)172 The Bullitt Center. (Image copyright agreements provided by Brad Kahn) 173

  List of Figures 

Fig. 5.21 The Bullitt Centre’s open plan office environment incorporates a minimalistic interior design within the high-performance net zero building. (Image copyright agreements provided by Brad Kahn) Fig. 5.22 The Bullitt Center’s energy performance (by Authors; Source: ILFI 2022) Fig. 5.23 (a) The urban context of the Bullitt Center, (b) overlooking Seattle’s skyline. (Image copyright agreements provided by Brad Kahn) Fig. 5.24 WGV Energy Village. (Image copyright agreements provided by Deo Prasad) Fig. 5.25 (a) WGV settlement aerial view and (b) the data collection process. (Image copyright agreements provided by Deo Prasad) Fig. 5.26 Narara Ecovillage under development in 2020. (Image copyright agreements provided by Julian Bassett) Fig. 5.27 Eighteen cluster units. (Image copyright agreements provided by Julian Bassett) Fig. 5.28 Named the ‘powerhouse with bedrooms’, this hempcrete house achieves 8.8-star NatHERS rating and includes a 20 kWp PV array. (Image copyright agreements provided by William Craft) Fig. 5.29 Narara Ecovillage energy balance over 6 months including summer (October 2021 to March 2022) (by Authors; Source: Narara Ecovillage 2022) Fig. 5.30 Atlassian Central. (Image copyright agreements provided by Jake Mascarenhas) Fig. 5.31 (a) Atlassian Central’s appearance from the street level. (b) Terraced roof gardens to improve site ecology and heat island effect. (c) ‘Neighbourhood gardens’ providing a connection to nature and natural ventilation. (Image copyright agreements provided by Jake Mascarenhas) Fig. 5.32 Kambri at ANU. (Image copyright agreements provided by BVN) Fig. 5.33 (a) Fenner Hall with student accommodation: Approximately 48% reduction in embodied carbon emissions (equal to 15 years of operational carbon) compared to a reference building. (b) Cultural Centre: a multi-purpose

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174 176 177 178 180 182 183

183 187 188

189 194

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Fig. 6.1 Fig. 6.2

Fig. 6.3 Fig. 6.4 Fig. 6.5 Fig. 6.6 Fig. 6.7

List of Figures

teaching and events facility. (c) Student Hub with collaboration and learning spaces. (Image copyright agreements provided by BVN) 195 Illustration of the Australian Government’s Plan to achieve net zero emissions by 2050 (Australian Government 2021b)202 Illustration of the three core areas of the Trajectory for Low Energy Buildings (The Commonwealth of Australia, Department of Industry, Science, Energy and Resources 2022)205 Australian state and territory objectives (Adapted from ClimateWorks Australia 2021) 206 The NSW Government planned to ban dark roofs to reduce urban heat island effects and energy consumption to achieve the net zero target for buildings (by authors) 208 Illustration of the four steps of the Sustainable Homes Transition Roadmap (CRC for Low Carbon Living and ASBEC 2019) 217 The Australian Zero Carbon Policy Nexus (by authors) 220 Illustration of building energy codes coverage worldwide (Global Alliance for Buildings and Construction and United Nations Environment Program 2021) (Source: International Energy Agency 2021b. All rights reserved). This map is without prejudice to the status of or the sovereignty over any territory, to the delimitation of international frontiers and boundaries, and to the name of any territory, city or area. Note: Recent updates are highlighted with a red border. Building energy codes relating to specific cities only are not shown225

List of Tables

Table 1.1 Remaining carbon budgets for estimated global warming scenarios4 Table 1.2 Summary of selected operational and embodied carbon reduction ­targets from 2020 to 2050 globally 12 Table 2.1 Inputs for the building energy/carbon simulation 36 Table 2.2 Fuel mix CO2 emission factors in Australia 40 Table 2.3 Building archetypes and classifications (ABCB, 2019) 43 Table 2.4 Global targets for operational carbon reduction 2020–2050, as defined by different institutions and organisations 56 Table 2.5 Australian states’ targets for net zero emissions and the electricity emission variations from 2020 to 2030 58 Table 2.6 Australian pathways for operational carbon reduction, as defined by different institutions and organisations 59 Table 3.1 Embodied carbon comparison of 1 m2 of brick wall fair faced (kgCO2-e) A1–A3 (excluding preliminaries) 89 Table 3.2 Whole building comparison (brick only) (kgCO2-e) A1–A3 (excluding preliminaries) 91 Table 3.3 Targets for embodied carbon reduction 2020–2050 93 Table 3.4 Comparison of published embodied carbon benchmarks for Class 1 and 2 buildings (detached residential and apartments)94 Table 3.5 Comparison of published embodied carbon benchmarks for Class 5 and 6 buildings (office and retail) 96 xxvii

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Table 4.1 Australian climate emergency targets for operational carbon performance for new buildings and major renovations 128 Table 4.2 Embodied carbon performance targets for new buildings and major renovations 131 Table 4.3 2020 indirect (scope 2) emission factors for purchased electricity136 Table 4.4 Implementation checklist 138 Table 4.5 Reporting template 139 Table 6.1 Optimal operational energy performance targets set by the City of Sydney Council for implementation through their LEP or DCP.  211 Table 6.2 Comparison between NatHERS, BASIX, NABERS and Green Star.  213

List of Boxes

Box 1.1 Box 1.2 Box 3.1 Box 3.2 Box 3.3

Scope of Greenhouse Gas Emissions in Buildings Defining Operational and Embodied Carbon Concrete and Cement Steel Timber

6 7 109 110 110

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1 The Climate Emergency and the Built Environment

1.1 The Climate Emergency It is unequivocal that human influence has warmed the atmosphere, ocean and land. Widespread and rapid changes in the atmosphere, ocean, cryosphere and biosphere have occurred. (IPCC 6th Assessment Report, 2021, p. 4)

The scientific case for climate change is robust and well established, with human activities the primary cause. This has been driven largely through the burning of fossil fuel (e.g. coal, oil, gas) and the subsequent release of greenhouse gases (GHG) (UNEP 2020). Since the industrial revolution, concentrations of greenhouse gases (GHG) have increased in our atmosphere, with annual averages currently around 410 parts per million (ppm) for carbon dioxide (CO2)—the highest level in millions of years. Increasing concentrations of GHGs in the atmosphere trap heat, and have raised the earth’s average temperature around 1.1°C as compared to the pre-industrial era (IPCC 2021). This change has increased the severity and frequency of extreme weather events such as heatwaves, droughts, flooding, hurricanes and wildfires, subsequently having a catastrophic impact on people and communities (Fig. 1.1). There are numerous studies that have reported how climate-induced natural disasters have caused significant environmental, economic, social © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022 D. Prasad et al., Delivering on the Climate Emergency, https://doi.org/10.1007/978-981-19-6371-1_1

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Fig. 1.1  Climate-influenced disasters and extreme weather events, 2012–2021 (Source: data from NOAA 2020)

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and health consequences. A heatwave, for instance, can be defined as a period of excessively hot weather which is exacerbated by global warming and is amongst the deadliest climate-induced natural disasters. The number of people exposed to extreme heat has increased by about 125 million from 2000 to 2016, and more than 166,000 people have lost their lives due to heatwaves during the period from 1998 to 2017 (WHO 2020). The 2003 heatwave in Europe alone led to the death of more than 70,000 people (Robine et al. 2008). Economic losses caused by climate-related disasters are also significant. In European Economic Area (EEA) Member States from 1980 to 2019, climate-related monetary losses were about €446 billion, equal to around 3% of GDP (European Environment Agency 2021). In a single year in Australia (2019–2020), catastrophic bushfires led to more than $103 billion (AUD) costs in property damage and economic losses (Read and Denniss 2020). In Africa, climate change is a key driver of hunger and food insecurity, with the poor over-represented in those affected by extreme weather events (World Meteorological Organization 2020). While the current impacts of our warming climate have been significant, future ones will be worse still. Projections of global warming suggest that global average temperature will keep increasing in the coming decades. According to data from the Climate Action Tracker (November 2021), global warming could increase by 4.1 to 4.8°C by 2100, as compared to pre-industrial levels, if no climate policies are implemented. Our current policies could lead to an estimated temperature increase of 2.5 to 2.9°C by 2100, while current pledges and targets would lead to warming of around 2.1°C. Some research suggests warming could be kept below 2°C if all current conditional and unconditional pledges are implemented in full and on time (Meinshausen et al. 2022). However, as shown in Fig. 1.2, emissions pathways to meet the more aspirational goal of a maximum of 1.5°C of warming require a steeper and more substantive set of emissions reductions still. But just how quick and how substantive should these reductions be? According to the United Nations Environment Program, global GHG emissions stood at 59.1 GTCO2e (including land-use change) in 2019, and have been growing at an average of 1.3% per year since 2010 (UNEP 2020). If we are to avoid warming above 1.5°C, we need to reduce

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Fig. 1.2  Global greenhouse gas emissions and warming scenarios (Ritchie and Roser 2022—Image CC-BY) Table 1.1  Remaining carbon budgets for estimated global warming scenarios

Source: data from IPCC (2021)

emissions to 25 GTCO2e by 2030—that is greater than a 50% reduction in less than a decade. Another way to look at this is to consider the cumulative carbon budget we cannot afford to exceed if we are to avoid different temperature limits. The Intergovernmental Panel on Climate Change (IPCC) set out the remaining carbon budgets in their sixth assessment report (see Table 1.1). For instance, if we are to avoid global warming of 1.5°C (with a 50% probability), we have a maximum remaining carbon budget of 500 GtCO2. This is equivalent to less than nine years of 2019 emissions.

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What this emphasises is that emissions reductions need to be both radical and rapid to avoid climate catastrophe—we cannot delay. The language we use to acknowledge the pace of change needed, and the consequences of delays, is important. In 2019, Oxford Dictionaries announced ‘climate emergency’ as their word of the year, in response to the growing sense of public awareness and scientific imperative around the need for change. This was defined as “a situation in which urgent action is required to reduce or halt climate change and avoid potentially irreversible environmental damage resulting from it” (Oxford Languages 2019).

1.2 Carbon Emissions and the Built Environment What is the role of the built environment in the climate emergency? We know the construction and operation of our buildings and infrastructure has a significant impact on the natural world, contributing to pollution, resource depletion, reductions in biodiversity and more. In terms of greenhouse gases specifically, buildings and construction are responsible for 37% of global energy-related emissions (UNEP 2021). This includes both direct (scope 1) and indirect (scope 2) emissions (collectively 27% from building operations), as well as 10% related to construction of buildings and manufacturing of construction materials (scope 3) (Fig. 1.3). An overview of the definition of each of these scopes is outlined in Box 1.1. The greenhouse gas emissions from the built environment occur across different stages of a building’s lifecycle. For instance, there are greenhouse gas emissions from creating a steel beam that might form a building’s floor. Iron ore is extracted from the earth, through mining. This is transported to a steel mill, where a blast furnace would mix the iron ore with carbon to create pig iron, which undergoes yet further processing to create steel. The steel would be fabricated into a beam, transported to site and erected to form a floor. All these processes can generate greenhouse gas emissions, and thus contribute to the climate emergency. Likewise, once the building is complete, it needs to be heated, cooled and ventilated, its spaces need to be lit, and the equipment within needs to be

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Fig. 1.3  Building and construction’s share of global energy-related greenhouse gas emissions, 2020 (UNEP 2021; IEA 2021a). ‘Buildings construction industry’ is the portion (estimated) of overall industry devoted to manufacturing building construction materials such as steel, cement and glass. Indirect emissions are emissions from power generation for electricity and commercial heat. (Source: IEA 2021a. All rights reserved. Adapted from ‘Tracking Clean Energy Progress’)

Box 1.1  Scope of Greenhouse Gas Emissions in Buildings Scope 1: Direct emissions from buildings • Fossil fuel consumption in buildings (gas boilers, cooking equipment, etc.). • Natural and synthetic refrigerants. Scope 2: Indirect emissions from building energy consumption • Electricity consumption by: (i) heating, ventilation and air-conditioning systems, (ii) refrigeration equipment, (iii) lighting and other building services (pumps, lifts, etc.) and (iv) equipment and plug loads (computers, appliances, etc.) • Energy from heating and cooling services provided by utilities and district plants Scope 3: Indirect emissions from other sources • Embodied carbon from materials in the building • Emissions from: (i) water use and sewage treatment; (ii) waste sent to landfill

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powered by electricity for the occupants to be able to function. At the end of a building’s life, it will be demolished, and its materials landfilled, or (ideally) recycled, again requiring energy and generating emissions. These emissions can be categorised as either ‘operational carbon’ or ‘embodied carbon’ and are defined in Box 1.2. When we combine operational and embodied carbon emissions together, we get the whole lifecycle carbon emissions of the building. The quantification of whole lifecycle carbon emissions over a service life has been guided by the ISO14044/14067 family of International Standards

Box 1.2  Defining Operational and Embodied Carbon Operational Carbon Emissions Operational carbon refers to the total direct (scope 1) and/or indirect (scope 2) GHG emissions from all energy consumed (operational energy) during the use stage of the building lifecycle. It includes both: • Regulated loads, for example, heating, cooling, ventilation and lighting • Unregulated/plug loads, for example, ICT equipment, cooking and refrigeration appliances Embodied Carbon Emissions Embodied carbon refers to the total of all direct and indirect GHG emissions arising from the production of, and processing activities for, producing materials and constructing the building. This includes the share of emissions associated with making the production process equipment and all other supporting business functions for bringing a product to the market. In addition, all emissions associated with transport of materials to site and the process of constructing the building itself are all included within the scope of embodied carbon emissions assessment. Embodied carbon can be measured within different system boundaries, for example, cradle to gate, cradle to site, cradle to construction completion, cradle to grave or even cradle to cradle. Some of these boundaries only include the emissions related to the upfront creation of the building. Others also include the maintenance and renovation of the building over its life, and the end-of-­ life emissions associated with demolishing, disposing and recycling the materials. Both operational and embodied emissions are usually expressed in kilograms of CO2e per unit floor area (KgCO2e/m2). Operational targets are often expressed in delivered energy per unit floor area per year (kWh/m2/ annum), for ease of measurement and comparability.

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Fig. 1.4  Scope of carbon emissions across the different stages of a building lifecycle (by authors)

(ISO 1997). EN:15978 (sustainability assessment of construction) goes further by providing a number of lifecycle ‘stages’ namely: • • • •

Stage A (product stage and construction). Stage B (use stage including operations and replacement capital works). Stage C (end-of-life). Stage D (beyond the building lifecycle). This is usually considered outside of the building scope but related to the concept of the circular economy (LETI 2021b).

These different stages are outlined in Figure 1.4. Considering the whole lifecycle carbon emissions of buildings, including both embodied and operational, is vital if we are to accurately understand, benchmark and reduce their environmental impact holistically.

1.2.1 Climate Action in the Built Environment: Towards Net Zero Emissions By 2030, the built environment should halve its emissions, whereby 100 per cent of new buildings must be net-zero carbon in operation, with widespread

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energy efficiency retrofit of existing assets well underway, and embodied carbon must be reduced by at least 40 per cent, with leading projects achieving at least 50 per cent reductions in embodied carbon. By 2050, at the latest, all new and existing assets must be net zero across the whole life cycle, including operational and embodied emissions. (UNEP 2021, p. 25)

We have established that there is a climate emergency, that we need to radically reduce greenhouse gas emissions and that buildings are a significant contributor. So what emissions reductions are necessary from the building sector in the short, medium and long term? A consistent move across the industry is towards ‘net zero carbon’ buildings. Net zero carbon, at a global level, can be understood as a scientific concept. At present, human-induced carbon dioxide emissions to and from the atmosphere are not in equilibrium. That is, our emissions (mostly from fossil fuels) far outweigh the planet’s ability to remove carbon dioxide from the atmosphere and store it in land and ocean sinks. Net zero carbon requires our carbon emissions to be significantly reduced, such that human-induced net carbon flows to and from the atmosphere, land and ocean are equal to zero (Fankhauser et al. 2022). At the building scale, net zero carbon can have different definitions, scopes, inclusions and exclusions, which can often cause confusion. Some definitions, for instance, only include operational carbon (scope 1 and 2) and exclude embodied carbon (scope 3). Torcellini et al. (2006, p.5) for instance define a net zero emissions building as one that “produces at least as much emissions-free renewable energy as it uses from emissions-producing energy sources”. Increasingly though, organisations are considering both embodied and operational carbon in their definition. The UK Green Building Council (UKGBC), for instance, have developed a Net Zero Whole Life Carbon Roadmap, which projects plans to achieve net zero carbon across the construction, operation and demolition of buildings and infrastructure in the UK, by 2050 (UKGBC 2021). In this book, we use the definition ‘net zero whole life carbon’ to consider net zero including both operational and embodied emissions (Fig. 1.5). Throughout this book, ‘net zero carbon’ means ‘net zero whole life carbon’. A building achieves a net zero whole life carbon status when, and maintains it until, the amount of carbon emissions associated with

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Fig. 1.5  Strategies to achieve net zero whole life carbon buildings (by authors)

both operational and embodied impacts over its nominated service life are net zero or negative. The ‘net’ zero status is achieved by first reducing operating and embodied emissions as much as possible, then (and only then) offsetting unavoidable carbon emissions through renewable energy generation or other eligible carbon offsets approved under the Climate Active Carbon Neutral Standard for Buildings or equivalent frameworks. Where specifically only operational (scope 1 and 2) or embodied (scope 3) emissions are referred to, ‘net zero operational carbon’ and ‘net zero embodied carbon’ terms are used respectively. While there is significant focus on net zero carbon buildings in the industry, it should be recognised that as things stand, only a tiny percentage of the building stock is designed to meet this performance criteria. The International Energy Agency (IEA) outline building targets needed

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Fig. 1.6  Percentage of zero carbon ready buildings needed in the total building stock, 2020–2050 (Source: by authors, with data from IEA 2021b)

to be met over the next three decades in order to reduce global emissions to net zero by 2050. They suggest the percentage of buildings in the total building stock that are ‘zero carbon ready’ needs to increase from less than 1% in 2020, to 25% in 2030, up to greater than 85% in 2050 (Fig. 1.6). A zero carbon ready building in this sense can be defined as one which is highly energy efficient, such that by 2050 a decarbonised electricity supply, or on-site renewables, can ensure the building will be net zero operational carbon without any additional changes or retrofitting (IEA 2021b). However, to achieve a net zero carbon-built environment, it is not enough to merely decarbonise our energy supplies and continue to build as normal, or with gentle incrementally improved efficiency. If all our buildings were electric-only and fossil fuel free, powered by a grid of renewable-only energy, then we could say we had met the net zero goal (in operations at least). But such a narrative belies the reality that while there is an abundance of renewable energy available in theory, our ability to harness and store it through the construction of wind turbines, solar panels, batteries and more requires finance, labour and materials, contributes to embodied carbon emissions and uses rare earth minerals. Fundamental to the net zero goal, then, is significant improvements to the energy efficiency of both new and existing buildings to reduce the

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absolute amount of energy we use, and ensure energy is available more equitably, across the globe. To be on track to meet net zero carbon operations by 2050, the energy demand of buildings per square metre needs to actually fall by 45% by 2030—that is a rate five times faster than it has fallen over recent years (UNEP 2021). To achieve net zero whole life carbon many peak bodies, industry associations and governmental and non-governmental organisations have set specific energy and carbon reduction targets and developed pathways or roadmaps for the built environment. A selection of these targets is outlined in Table 1.2 and in the following sub-sections. Consistent across many pathways are (1) that most new buildings will be net zero carbon (or net zero ready) in operations by 2030, (2) that embodied carbon in new buildings will be reduced by at least 40–65% compared to current levels by 2030 and (3) the roll out of accelerated programs to renovate Table 1.2  Summary of selected operational and embodied carbon reduction ­targets from 2020 to 2050 globally

In some cases, operational energy reduction percentages are used instead of greenhouse gas emissions (data from GBCA 2021; Architecture 2030 2021; RIBA 2021a; LETI 2020; C40 2018; GlobalABC et al. 2020; IEA 2022)

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and improve the energy efficiency of existing buildings such that all buildings are net zero carbon by 2050.

1.2.2 Green Building Council of Australia The Green Building Council of Australia (GBCA) Climate Positive Roadmap was released in 2018, with a revised version published in July 2021. It sets ambitious targets for operational and embodied carbon reductions for both Green Star and non-Green Star rated buildings at regular intervals until 2050. Central to this are the targets of new buildings being net zero operational carbon by 2030, and all existing buildings by 2050. In terms of embodied emissions, all Green Star rated buildings are required to reduce embodied carbon by 10% from 2020, with 6 star rated buildings required to reduce this by 20%. By 2030 Green Star rated buildings are expected to reduce embodied emissions by 40% (GBCA 2021).

1.2.3 Architecture 2030 Challenge The Architecture 2030 Challenge seeks to achieve the elimination of fossil fuel-related carbon emissions from the built environment by 2040— this includes both embodied and operational emissions. The benchmark for operational emission reductions is set as the average energy consumption of existing US buildings per region / local area. The original target set by the organisation was for all new buildings to be highly efficient and use no fossil fuels in operation by 2030—hence the name. However, there is an acknowledgement that this is too late, and that all new buildings completed from 2021 onwards should aim to be net zero carbon in operations (Architecture 2030 2021).

1.2.4 RIBA 2030 Challenge The RIBA 2030 Climate Challenge sets stepped reduction targets for operational energy, embodied carbon and potable water for 2025 and 2030 as part of a pathway for net zero carbon across the UK built

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environment by 2050. Targets are compared to ‘business as usual’ and include specific values for offices, schools and domestic construction with design teams encouraged to aim for 2025 targets as a minimum and, ideally, 2030 targets for buildings currently under design. While specific targets are defined for the three typologies, in general aims are a 60% reduction in operational energy, a 40% reduction in embodied carbon and a 40% reduction in potable water, by 2030. For instance, while a new build office would be expected to use 130 kWh/m2GIA/annum in 2021, the maximum should be