Net-Zero Buildings Where Do We Stand? Contents

Net-zero buildings Where do we stand? Contents

Foreword | 3

Executive summary | 5

1 Introduction | 7 1.1 Whole life cycle assessment methodology | 10 1.2 Net-zero buildings, benchmarks and targets | 15

4 Additional data on case studies | 50

Net-zero buildings Where do we stand? 2 Foreword

The built environment is a The case studies, all of which By doing so, we can help inform critical sector to tackle if focus on some degree of and educate all stakeholders and we are to reach the climate low carbon design, indicate provide greater opportunities mitigation targets set out a potential for clear targets to reduce emissions, driving in the Paris Agreement,1 as to emerge, and the halving more immediate action. it represents close to 40% of global buildings related of global energy-related emissions within the next For WBCSD and Arup, this carbon emissions. In 2020, decade to be a possibility. report represents an important the World Business Council collaboration toward better for Sustainable Development The high-level milestones being understanding how we can (WBCSD) published the proposed by 2030 globally on reduce all emissions from Building System Carbon the path to net-zero, are not out the construction and use of Framework to provide of reach, but to achieve them, buildings to achieve net zero. a common language to whole life carbon assessment Going forward, we will explore companies and other is critical and needs to inform together with a wider group stakeholders involved in the widespread decision making. of WBCSD members the key built environment on how they levers, strategies and actions can collaborate to achieve The case studies also help us that will help us reach net- decarbonization across the to better understand the key zero emissions across the full life cycle of buildings. levers that will drive the built full life cycle of buildings. environment decarbonization, The Framework provides a for example, in new building We look forward to engaging clear overview of all the carbon projects more than 50% of many stakeholders in this emissions in the building emissions may be from the work and to sharing and system over a full life cycle, embodied carbon associated further developing the learning and it enables reflections and with the construction, and 70% widely so that the buildings opportunities for dialogue of this comes from six materials. and construction sector between all stakeholders. As much as 20% of life-cycle can decisively accelerate emissions come from the collaboration and action This report presents and maintenance and refurbishment toward net-zero buildings in discusses the results of six case of installations during the the critical next few years. studies developed from Arup lifetime of a building. Hence it is projects using whole life carbon paramount that we tackle these assessment of buildings based emissions alongside a continued on the WBCSD Framework. focus on driving down emissions The work shows that it remains from the energy used to operate difficult to collect all the buildings. The report discusses necessary data from across the some approaches and potential full life cycle of building projects. targets to accelerate action. Roland Hunziker Despite this, it is critical that we Director, Sustainable Buildings & Cities, start using this information to Based on this work we call on WBCSD inform the earliest phase of the companies from across the decision-making process when built environment and around the opportunity to reduce whole the globe to conduct whole life carbon emissions is greatest. life carbon assessments of their projects as a matter of course, openly publishing the results so we can create and build a body of evidence Chris Carroll and shared learning. Building Engineering Director, Arup

Net-zero buildings Where do we stand? 3 2 With willingness and Figure 1: Route to net-zero buildings, UNFCCC (2021) a holistic look at all emissions occurring over the lifetime of buildings we can achieve significant emissions reductions immediately. For this to 2030 100% of new buildings happen, collaboration must be net-zero carbon and a whole life carbon in operation, and embodied carbon must be reduced approach from the by at least 40% very start of any project are critical.

Roland Hunziker 2050 All new and existing assets must be net-zero across the whole life cycle

Figure 2: Buildings share of global energy emissions, To achieve the required Global ABC/IEA/UNEP (2020)3 decarbonization of our buildings we have to rapidly gain wider 23% 19% understanding of the whole life cycle 9% impact. From this 7% informed position we 10% can then collaborate intelligently to 32% make deep and meaningful reductions Buildings operational indirect emissions Other industry toward net zero. Buildings operational direct emissions Other Buildings construction industry Transport Chris Carroll

Notes: Direct emissions are those emitted from buildings, while indirect emissions are emissions from power generation for electricity and commercial heat. Land use change is not included in the global energy emissions.

Net-zero buildings Where do we stand? 4 Executive summary

This report looks in detail at the results of six whole life cycle carbon assessments E (WLCA) case studies to m bo d illustrate some of the current ie d challenges, barriers, and A 1 opportunities relating to the - A l 5 buildings industry’s carbon a

n footprint. It aims to provide o i t Whole life

an insight into the industry’s a r current performance in e carbon emissions p kgCO2e/m2 relation to possible net-zero O trajectories and identify some potential next steps to aid the sector’s journey toward -C total decarbonization. B ed di bo We ask the reader to consider Em the question posed by the report “Where do we stand?” with respect to the immediate demands on the global building improvement. Should this target carbon has generally little impact industry to decarbonize as a be committed to universally on overall figures, except when key part of tackling the climate as a starting point we would considering organic material emergency we all face. make good immediate in- such as timber where more roads into significant global clarity on possible end of life KEY OUTCOMES emissions reduction. scenarios is still needed. The six projects represent a small sample, and likely the In-use and end-of- Operational more advanced end of the life embodied B-C The operational energy use industry. However, they provide The case studies point varies significantly across a good insight into a building’s to a current lack of clear the case studies from around whole life carbon footprint understanding regarding the 75 to 220 kWh/m2/year. The and how it is broken down into in-use embodied carbon which units here are provided in total key constituent parts, further averages above 300 kgCO2e/ energy consumption rather described in section 1 of this m2 using currently established than in GHG emissions owing report. The case studies point accounting methods. Greater to regional variability in the to outcomes regarding current focus is required to design out carbon intensity of the grid. Most achievable performance this impact through the adoption of the case studies estimate and alignment against the of circular economy principles energy consumption based on developing net-zero pathway. as opposed to wholesale calculations. Moving forward, replacement of key components we need to collect better in- Upfront embodied A1-A5 as currently assumed. We also use energy data to verify these Looking across the six case need more transparent and assumed values. In addition, an studies, the upfront embodied accurate understanding across improved understanding of the carbon averages between 500- the industry in relation to the decarbonization of the supply 600 kgCO2e/m2, and it would decarbonization of materials grid over the building’s life is seem a global target in this over time to make the right required to clearly determine vicinity could be established decisions to minimize whole life whether we are on track to immediately, representing an impacts. The case studies also achieve the necessary overall achievable level of universal show that end of life embodied emissions reductions.

Net-zero buildings Where do we stand? 5 KEY CHALLENGES AND KEY MESSAGES Define explicit targets OPPORTUNITIES Commit to WLCA • Clear, simple global targets One important observation on all projects adopted across the buildings has been the difficulty and • Measure everything, at all industry. time taken to develop the case stages, on all projects. • A valid approach to residual studies. Significant effort was • Consistent methodology and carbon emissions. required to collect consistent approach. • Supportive international and levels of WLCA data across • Process of open source country-specific policy and all projects. We must rapidly sharing of data. legislation. improve the process of creating and sharing transparent WLCA data. The current availability Develop consistent and Define net-zero buildings and consistency of the carbon transparent carbon intensity • Clear and precise definition of intensity data associated with and benchmark data net-zero buildings aligned with building components and • All components, systems and overall global decarbonization, materials in different parts materials to have a carbon emerging net-zero definition of the world is of particular intensity certification. and the Paris Agreement. concern. The case studies • Collect and share in-use indicate that around 70% of all energy consumption data. Establish wider collaboration upfront embodied emissions • Better understanding of • Individual organizations taking are associated with only supply chain and national action is not enough. six materials. It would seem energy grid decarbonization • Rapid industry-wide systems plausible that, through industry trajectories. change is required. focus and collaboration, • All stakeholders across the we can drive reduction of value chain must play their embodied carbon emissions part. through research, development and knowledge sharing.

KEY TERMINOLOGY

• Carbon dioxide equivalent • Embodied carbon refers • Operational carbon refers emissions (CO2e) to a quantity of CO2e to the emissions associated represents an equal GHG associated with the with the heating, cooling, and emissions quantum. It is materials used to construct energy use of the building. commonly use since it is and maintain the building the major component of throughout its lifespan • Whole Life Cycle GHG emissions (burning of (material extraction, Assessment (WLCA) is a fossil fuels, waste, biological manufacture, construction, method to quantify both materials, emissions from demolition and end of life). embodied and operational chemical reactions). carbon emissions of an

asset over its life cycle.

Net-zero buildings Where do we stand? 6 1 Introduction

Introduction | 8

1.1 Whole life cycle assessment methodology | 10

1.2 Net-zero buildings, benchmarks and targets | 15

Net-zero buildings Where do we stand? 7 1 Introduction

To meet the ambitions of the Currently the industry lacks a discuss the results in relation Paris Climate Agreement well-established and universal to net-zero trajectories. and limit global warming to understanding of the detailed It is important when assessing +1.5°C above pre-industrial challenges associated with the the carbon impact of a building to levels, we need to manage decarbonization of the built understand the constituent parts and mitigate greenhouse gas environment. The approach as they build up over time (fig. 4 (GHG) emissions to a credible toward achieving GHG reductions and fig. 5). The WLCA includes version of zero by adopting across the whole industry, all the building's life stages, often a systems thinking approach design, construction, delivery referred as “from cradle to grave”. to our anthropogenic and operation needs to be much Over the past decade, the focus activities and impacts.4 better informed by knowledge has been mainly on reducing the sharing, data transparency, operational carbon emissions Approximately 38% of energy research and innovation. This also associated with buildings. As related GHG emissions are relates to property developers, a result, embodied carbon of attributed to the building financiers and policy makers new buildings now represents industry, 28% derive from who influence the value chain. a significant contributor to total building operation and 10% emissions, often as much as 50% from the materials used in their Understanding the whole life of the total life cycle emissions construction and maintenance.3 carbon emissions of buildings is as illustrated by this study. It is estimated that approximately a key step towards meaningfully 255 billion m2 of buildings creating reductions and credible This study is only part of a currently exist in the world. pathways towards net zero. beginning to the process of With an addition of roughly We need to more accurately measuring and importantly 5.5 billion m2 every year, a city understand where we are, reducing whole life carbon the size of Paris is constructed where we want to get to, and emissions. Currently very few every single week.5 importantly, how we get there. projects globally have rigorous carbon assessments and we Clearly, we must significantly The purpose of this report need to change this situation and rapidly address the GHG is to put a spotlight on the quickly. This is not yet a trivial emissions associated with carbon footprint range of exercise as the WLCA requires the building industry to be existing buildings' projects; assumptions to be made on track with our overarching show where and when the regarding current and future CO2e decarbonization emissions. emissions occur during intensities of both the energy and the building’s lifetime and materials supply.

Figure 3: Global Annual CO2 Emissions (Mt), Our World in Data and Global ABC/IEA/UNEP (2020)3, 6

40,000

35,000 In 2019, 30,000 Buildings contributed 25,000 to 38% of emissions: 20,000 13,850Mt

15,000

10,000

5,000

0 1850 1870 1890 1910 1930 1950 1970 1990 2010 2030

Net-zero buildings Where do we stand? 8 We explore these assumptions field in development and it 2. Case studies. The second in more detail and we point to is not a precise science. The section summarizes the six the current limitations in relation assumptions are based on case studies providing an to assessing and reporting best available information. introductory overview of whole life carbon and to the The importance here is to the buildings and outlining need for consistency and rigor understand the main drivers, the results of the WLCAs in the methods adopted with a what the biggest contributors using the Building System particular focus on; the life cycle are and what needs to be done Carbon Framework published stages, the building elements to reduce our carbon impact. by WBCSD in 2020 as the scope, the general assumptions principal reporting structure. made and the decarbonization OUR APPROACH scenario adopted for energy use. 1. Framework. The first section 3. Analysis. The third section of this report describes the analyzes the results Collecting and sharing data methodology adopted for highlighting common relative to the carbon footprint the WLCA case studies. synergies, challenges and of individual projects will help to We integrate the global 2030 limitations. The results are build up a better understanding and 2050 decarbonization discussed in line with the of where we are currently vision for the building targets proposed in the first and where we need to get to industry proposed by section. This seeks to present as global industry in relation WorldGBC, which is now an indicative outline of current to the high-level vision to widely supported by achievable performance decarbonize all buildings by key organizations such against a potential net-zero the middle of this century. as WBCSD, GlobalABC, trajectory. The case studies address WMB and the UNFCCC the need for transparent data Marrakesh Partnership 4. Supporting data. The fourth by sharing the information Climate Action Pathways. To section acts as an appendix such as the building general relate this high-level vision giving detailed information description and systems, the to our case studies, we on each of the six case highest contributing materials discuss WLCA benchmarks studies WLCAs. This fulfills and components, the energy and potential targets. one of the key objectives consumption and the carbon of this study which is to factors chosen. It is important report transparently the data to note that WLCA is still a used in the case studies.

Figure 4: Estimated distribution Figure 5: Whole life carbon emissions, Arup (2020)7 of carbon emissions per life cycle refurbishment Replacement and disposal Demolition and stage Construction Operation Operation Material re-use products and processes

50% 30% s n o i s s i m e

20% n o b r e c a f

Embodied A1-A5 i l

Embodied B-C o l h W Operational B6-B7 Time

Net-zero buildings Where do we stand? 9 t f s e o f

n o r b a C

Client / Developer Designer Contractor User Operator / FM 1. 1 Whole life cycle assessment methodology

GENERAL APPROACH As this study is intended to be • The site emissions are A key aspect of a WLCA is to internationally representative, reported in a distinct cell adopt some form of recognized we have built upon the work In both cases, the carbon and standardized methodology of WBCSD and adopted the compensation row figuring in so that benchmarks and targets Building System Carbon the BSCF was removed as it can be established in a consistent Framework (BSCF, fig. 6) was out of scope for this work. way. Currently a number of to present our results. methodologies are emerging SYSTEM BOUNDARIES with consistent principles In addition, we have integrated • The building’s life cycle is split across each. For example: the RICS building elements into different life cycle stages • International Organization for classification in the section 4 of A to D, themselves divided in Standardization (2006), ISO this report, as this is the most modules. These are described 14040: 2006 Environmental used reporting format so far in the EN 15978:20116 and Management - Life cycle owing to its advanced stage summarized below: Assessment - Principles and of maturity. This approach will 8 Framework help when comparing available Stage A: Product and industry benchmarks. • European Standard EN15978 construction (2011), Sustainability of The end of this stage marks The differences between the Construction Works – the practical completion of BSCF table used to report Assessment of Environmental the building. This stage only the case study summaries Performance of Buildings – relates to embodied carbon. Calculation Method9 and the extended version presented in section 4 are: • Royal Institution of A1-A3: Product stage and • The structure is divided Chartered Surveyors (RICS) manufacturing – accounting between substructure and (2017), Whole Life Carbon for the carbon emissions superstructure Assessment for the Built associated with the "cradle to Environment10 • The space plan is divided gate" processes: raw material between internal walls and • WBCSD (2020), The Building supply, transportation and 11 internal finishes System Carbon Framework manufacturing processes.

Figure 6: Building System Carbon Framework, WBCSD (2020)11

BUILDING STAGES

PRODUCTS CONSTRUCTION USE END OF LIFE EMISSIONS BEYOND LIFE

A1-A3 A4-A5 B1-B5 B6-B7 C kgCO2/m2 D Structure Foundation, load-bearing Skin Windows, roof, insulations Space plan Interior finishes Services Mechanical, electrical, plumbing

BUILDING LAYERS Stuff(optional) Furniture and appliances

Building carbon emissions

Carbon compensation Removals and offset

Embodied carbon Operational carbon Partial and total sums

Net-zero buildings Where do we stand? 10 A4-A5: Construction stage B6-B7: In use operational – recovered from beyond the process – accounting for the accounting for the carbon project’s life cycle. This seeks carbon emissions associated emitted throughout the utilization to present a wider picture of the with the transportation of of the building (energy and environmental impacts of the the materials to site and the water). Operational energy project and accounts for the construction itself (material may be calculated using the future potential of the products wastes, construction plant current grid energy carbon and the circular economy. and machineries). factor and accounts for The carbon emissions associated decarbonization scenarios in with Module D are generally not Stage B: In use line with national assumptions. included within the whole life Throughout this stage, the carbon emission as they are building is in function. It is Stage C: End of life outside the building system. The divided in five modules relating This stage is associated with values are however interesting in to embodied carbon and two the demolition and waste the context of circular economy. relating to operational carbon. processing of construction materials. It generally has a low Further information on WLCA B1-B5: In use embodied – impact however when using methodology and calculating accounting for the carbon biogenic material, the disposal embodied carbon can be emissions associated with the will release a part or all of the found in RICS and IStructE maintenance, repair, replacement sequestered carbon to the guidance referenced at this and refurbishment of the atmosphere depending of the end of this report.10, 12 built asset over its lifetime. end of life scenario considered. For buildings, embodied In this study, the scope emissions generally only concern Stage D: Beyond life benefits considers modules A, B and C B4 – owing to the availability of This module accounts for and reports module D separately. data at the time of reporting. benefits or burdens associated with repurposing building elements e.g. discarded materials from the built asset or energy

Figure 7: Whole life cycle stages, EN15978 (2011)10

Whole life carbon

Upfront carbon Embodied carbon Product Construction In-use End of life Beyond life cycle

A1 A2 A3 A4 A5 B1 B2 B3 B4 B5 C1 C2 C3 C4 D Use Reuse Repair Disposal Recovery Transport Transport Transport Recycling demolition Replacement Maintainance Manufacturing Refurbishment Construction and Waste processing Waste Benefits and loads Raw material supply Raw material Deconstruction and Deconstruction installation processes

Operational carbon B6 Operational energy

B7 Operational water

Cradle Gate Site Practical completion End of life Grave Beyond life

Net-zero buildings Where do we stand? 11 BUILDING ELEMENTS SCOPE The scope of an WLCA also needs to specify which parts and elements of the building are to be assessed. This is essential to be able to create benchmarks and is often not clearly defined.

In this study, the scope encompasses the elements from the table below which uses the WBCSD BSCF reporting structure linked back to the RICS categories.

Each building element category refers to a particular color used consistently throughout the report as per the table below.

Table 1: WBCSD (2020) and RICS (2017) building elements categories10, 11

WBCSD RICS

BSCF Level 1 Element Group Level 2 Element Group

Structure 1 Substructure 1.1 Substructure

2 Superstructure 2.1 Frame

2.2 Upper floors

2.3 Roofs

2.4 Stairs and ramps

Skin 2 Façade 2.5 External walls

2.6 Windows and external doors

Space Plan 2 Internal walls and partitions 2.7 Internal walls and partitions

2.8 Internal doors

3 Internal finishes 3.1 Wall finishes

3.2 Floor finishes

3.3 Ceiling finishes

Stuff 4 FF&E 4.1 Fittings, furnishings and equipment

Services 5 Building services 5.1 – 5.14 Building services

Net-zero buildings Where do we stand? 12 GENERAL ASSUMPTIONS While creating these case make assumptions based to make good comparisons. studies, we realized that it is on the best available data. To this end we have for this not yet trivial to gather data Ultimately it will be important as particular study used the on all parameters influencing we grow the database of WLCA following key assumptions the results (material quantities, for projects globally that there is which can be developed specifications, carbon factors, a general level of transparency and adapted in the future. etc.). Therefore, we need to and consistency allowing us

Table 2: Whole life cycle WLCA case studies – general assumptions

General Best guesses are made on build-ups, thicknesses and material selection at the time of the project assessment.

Allowances are made for categories where material quantities are unknown (typically building services) based on past projects.

Transportation scenarios10 50km – Locally manufactured 300km – Nationally manufactured 1,500km – European manufactured

Element lifespan10 Structural frame and foundations – 60 years Roof coverings – 30 years Partitions – 30 years Finishes – 30/20/10 years Façade elements – 35/30 years FF&E – 10 years Services – 20 years

Building life 60 years

Services Factor assumed of 120 kgCO2e/m2 for services within office buildings; and 70 kgCO2e/m2 for services within residential buildings. CIBSE (2013).10

Construction site impacts OneClick LCA Europe factor of 30.34 kgCO2e/m2 (A5w + A5a)13 GIA which assumes an average production of construction waste of 5 kg/ m2, an electricity use of 37 kWh/m2 and a total use of diesel 4.5 l/m2.

Carbon factors data sources15 Environmental Product Declarations (EPD) from manufacturers Databases: Inventory of Carbon and Energy (ICE), Ecoinvent, Okobaudat, Inies OneClick LCA carbon factors Material carbon factors assumed constant throughout the WLCA (not accounting for material decarbonization)

Net-zero buildings Where do we stand? 13 ENERGY USE – way, we have been forced for this figure matches with the latest DECARBONIZATION particular set of case studies to measured value while the 2050 SCENARIOS make a series of assumptions. targets would still be reached.17 The energy use intensity (EUI) of a building over its life span is The electricity operator for the This is viewed as a conservative typically calculated in kWh/m2 UK issued a series of Future approach as the “steady 16 – most regulations relate to this Energy Scenarios (FES). progression” scenario paints a energy use intensity and not The projections show how rather carbon heavy progression specifically to carbon emissions. governments decisions – compared to others that rely currently in place to reach on the grid to decarbonize It can be challenging to convert 2030 and 2050 targets – affect completely by 2050. the EUI into CO2e as it involves the grid carbon factor. both a clear understanding of the This means that this approach current production intensities The different scenarios relate to also pushes for optimization as well as a clear understanding the development of technologies of energy strategies and for a of how the production (i.e. the in renewable energies and the reduction of the global demand. grid) will decarbonize over time. strategies in place to reduce Current predictions on grid demand such as consumer Decarbonization scenarios have decarbonization rely heavily on engagement, improved not been applied to the building having a clear understanding home insulation and growth materials/components replaced of specific long-term national in electric vehicles usage. through stage B. This is owing strategies and the outcomes to a lack of data availability for in terms of available clean For the purpose of this work, the context of the case studies. energy mixes over time. There the FES scenario “steady is a lot of uncertainty globally in progression” projection is applied Each country needs to develop relation to real and verified grid to each country’s or region’s a better understanding of their decarbonization trajectories. currently available data, unless national grid decarbonization specified otherwise. For example, trajectories and clear and Since it is hard to gauge, in the UK, the data set has been simple process should be especially in a country-specific adjusted such that the 2020 agreed to undertake operational carbon calculations.

Figure 8: CO2 intensity of electricity generation – estimated progression

300

FES adjusted 250 Simplified

200 / kWh 2 150 GCO

100

2020 2025 2030 2035 2040 2045 2050 2055 2060 2065 2070 2075 2080

Net-zero buildings Where do we stand? 14 1.2 Net-zero buildings, benchmarks and targets

In the context of the building industry, the definition from the IPCC means that the demand for Net-zero carbon dioxide (CO2) emissions are construction materials and the demand for energy to operate achieved when anthropogenic CO2 emissions buildings need to be reduced to a are balanced globally by anthropogenic 4 point where it can all be sourced CO2 removals over a specified period. without emitting additional GHG emissions (figure 10). This needs Intergovernmental Panel on Climate Change to be considered at systems level but also accounted for at the level of individual building assets by applying the following principles: Figure 9: Embodied carbon reduction strategy

1. Designing more efficient Repurpose / refurbish buildings buildings – reduce material Build nothing (Design flexible and and energy demand adaptable structures) 2. Using circular economy Build only to meet needs of principles – reuse existing Build less communities / cities material and design new Maximize utilization of buildings, Less fit-out buildings to be dismantlable and reusable Reuse materials Build clever (Design for deconstruction and reuse) 3. Using renewable energies and Use low carbon materials / products low carbon materials Minimize design loads 4. Neutralizing residual carbon Build emissions. Use efficient forms and grids efficiently Maximize material utilization Although consensus is still building, certain types of offset Minimize Prefabricate are possibly an option to Improve construction practices waste Utilize reuse or recycling streams balance the minimised residual emissions and pursue a global net-zero built environment.

Figure 10: Net-zero strategy for the built environemnt, Arup (2020)7

Reduce materials and energy demand

Supply / demand balance

Increase low carbon materials supply and renewable energy

2020 2050

Net-zero buildings Where do we stand? 15 EMERGING BENCHMARKS EMBODIED CARBON TARGETS business as usual embodied AND TARGETS TOWARD The list below outlines some carbon at practical completion NET-ZERO examples where more defined to be 950 kgCO2e/m2 and To meet the targets outlined targets are beginning to emerge. 1,400 kgCO2e/m2 over the within the Paris Agreement, The representative sample whole life. They recommend scientists have estimated that further showcases where aspirational targets at the building industry needs different parts of the building respectively 500 kgCO2e/m2 to reach net zero by 2050.1 industry can collaborate towards and 850 kgCO2e/m2.21 a single goal. This section The World Green Building also attempts to understand Carbon Leadership Council broke down the net-zero what business as usual carbon Forum (CLF) – Initiative objective between embodied impact might look like – to be The CLF (based in the United carbon and operational able to assess and frame the States) unites professionals carbon, implementing a 40% reduction on embodied 18 15 from the built environment major milestone in 2030. carbon aimed at by 2030. to accelerate the transition to net-zero with a focus This high level vision is becoming Royal Institute of British on embodied carbon. a recognized objective by Architects (RIBA) – Institution influential organizations such as RIBA is the main professional • Embodied: CLF estimates WBCSD, GlobalABC and UNEP body representing architects the Stage A carbon impact and is being adopted more in the United Kingdom and well of the structure, substructure widely as awareness builds. recognized internationally. RIBA and façades to be less sets the following targets: than 1,000 kgCO2e/m2. In The definition of net-zero addition, their studies show carbon and the short period of • Embodied: 1,100 kgCO2e/ that the substructure and time allowed to reach it unveils m2 as a business as usual superstructure (for offices) a massive challenge for the benchmark over the whole is typically responsible for construction industry which life with best practice 500 kgCO2e/m2. As these needs to adopt immediately representing 500 kgCO2e/m2 generally represent 50-60% new ways of designing much by 2030 for non-domestic of the total upfront carbon more efficient buildings with buildings. emissions, we deducted from sustainable resources. the CLF studies, a benchmark London Energy Transformation figure of 950 kgCO2e/m2 for In order to react in time, the Initiative (LETI) – Initiative BAU.22 construction industry needs LETI regroups professionals to set clearer and more explicit from the built environment One Click LCA Ltd – targets. This will encourage dedicated to put London on One Click LCA Ltd. is the universal measurement of an exemplary path to reduce developer of the LCA and carbon emissions, set short carbon emissions. They LCC Software, One Click. and long term priorities on how recommend the following: to reduce them and accelerate • Embodied: Based on an the transition toward a net-zero • Embodied: Baseline of extensive dataset of office carbon built environment. 1,000 kgCO2e/m2 and a buildings in twelve Western best practice 2020 target of European countries, they <600 kgCO2e/m2 for office estimate the current buildings. benchmark (2021) for embodied carbon at practical Greater London Authority completion as 600 kgCO2e/ (GLA) – Policy m2. This number corresponds The GLA is the official to a minimum scope of governance body of London substructure, structure and which notably regulates the façade, which are generally built environment and provides responsible for approximately construction permits. 70% of the upfront carbon. Therefore, the full scope • Embodied: For office should approximate 900 buildings, GLA estimated the kgCO2e/m2.23

Net-zero buildings Where do we stand? 16 By 2030, new buildings, infrastructure and renovations will have at least 40% less embodied carbon with significant upfront carbon reduction, and all new18 buildings must be net-zero operational carbon.

Whole life carbon vision (WorldGBC)

Figure 11: Upfront embodied carbon targets

1,200 A1-A5 GLA

A1-A5 CLF 1,000 A1-A5 LETI

800 GIA)

2 -40% e/m

2 600 (kgCO 400

2020 BAU A1-A5 200 1,000 kgCO2e/m2

2030 Targets 0 600 kgCO2e/m2 Business 2030 Targets as usual

Figure 11 presents current Although this would represent Should this be the agreed business as usual (BAU) a progressive target if achieved baseline for comparison, the figures in comparison to on a global scale, consideration case study selection would indicative 2030 targets for should be given based on suggest already progressive upfront embodied carbon and these, albeit advanced, case whole life embodied carbon whole life embodied carbon studies as to whether this results. Clearly, much more within the industry context. is ambitious enough. global data is required in this field to establish clear BAU Although by no means a Further to proposing a benchmarks and from there rigorous process, a number construction (A1-A5) BAU value set clearer and fixed targets. of the key organizations we have subsequently estimated referenced within this report an extra 30% for the whole life Where targets are not point to a value of circa 1,000 embodied benchmark (based aspirational enough, the industry kgCO2e/m2 as a credible on RIBA, GLA and Arup past should revisit these in line with value to capture global BAU projects). This would give a emerging research, innovation upfront embodied carbon WLCA (A-C) embodied carbon and collected data to better benchmarks (A1-A5). BAU reference value in the establish, assess and ultimately region of 1,300 kgCO2e/m2 reduce the in-use embodied If this was accepted, the 2030 against which we can compare carbon emissions associated target of a minimum 40% our case study results. with our building projects. reduction would establish a future target for all projects of a maximum of 600 kgCO2e/m2.

Net-zero buildings Where do we stand? 17 OPERATIONAL Climate Risk Real Estate Typically, the energy use CARBON TARGETS Monitor (CRREM) – Tool intensity (EUI) of a building over Similarly, the organizations Climate Risk Real Estate its life span is calculated and referenced below are beginning Monitor is a tool developed reported in kWh/m2, as opposed to propose targets on buildings with funds from the European to kgCO2e/m2, to reduce the Energy Use Intensity (EUI) and Commission Horizons 2020 level of assumptions needed to their respective carbon impact program by a consortium of 5 account for particular national aligned with a view of achieving partners including academic energy grid carbon intensity and a credible reduction in EUI institutions and SMEs. CRREM decarbonization trajectories. demand by 2030 to guide the defines the decarbonization If a project is to be zero carbon industry toward decarbonization. pathway for buildings in in operation by 2030, the EUI alignment with the commitments needs to reduce to a point Royal Institute of British of the Paris Agreement. where it can be fully provided Architects (RIBA) – Institution by renewable energy supply. • Operational: CRREM • Operational: The energy use developed building use The data shown in the diagram intensity should progressively specific decarbonization opposite corresponds to office regress from 225 kWh/m2 pathways for all EU countries buildings as an example. Clearly, (usual benchmark) to 55 and the largest international each country should establish kWh/m2 for non-domestic real estate markets. The and clarify specific target data buildings.19 pathways are bespoke to the in line with their own national buildings' country of origin energy system decarbonization London Energy Transformation and the sectoral market. trajectory as a key next step. Initiative (LETI) – Initiative The pathways are expressed in both kgCO2e/m2 and kWh/ The second graphic translates • Operational: LETI also targets m2. For the purpose of this the EUI in carbon emissions of 55 kWh/m2 for office buildings report, we are expressing UK initiatives (LETI/RIBA/UKGBC) with 15 kWh/m2 attributed to the CRREM pathways as using the UK grid carbon factors heating.20 decarbonization targets. Refer (as available at the time) and to Figures 12 and 13.25 applying the decarbonization trajectory scenario described The Real Estate Environmental previously in the report. It shows Benchmark (REEB) – Initiative Swiss Engineers and that to meet the suggested UK Set by the Buildings Better Architects Association (SIA) demand target by 2030, 10kg/ Partnership, the REEB – Association CO2e/m2/year will need to be benchmark is a publicly available provided via clean energy. As a operational benchmark for • Operational: The SIA 2000- mean of comparison, the CREEM commercial buildings in the UK. Watt Society Energy Efficiency pathways for UK, DK and ND are The benchmark is based on the Path sets an operational also plotted on the graphic. buildings 'in-use' data adopting energy 2050 target for a 3-year rolling average. new and refurbished office Clearly, there is a great need • Operational: For office buildings at 80kWh/m2 and for better, clearer data and buildings, REEB presents 100kWh/m2 respectively. By more transparency from a a 2019 benchmark for 2050, this would correspond wider number of individual operational energy threshold to 4 and 6 kgCO2e/m2/year 26 countries in relation to setting of 233 kWh/m2 for air- respectively in Switzerland. 24 targets aligned with credible conditioned offices. national energy system decarbonization scenarios.

Net-zero buildings Where do we stand? 18 Figure 12: Energy use targets

300 LETI

RIBA / UKGBC 250 REEB

CRREM UK 200 CRREM DK

150 CRREM ND GIA/year) 2

100 (kWh/m

2020 BAU average 50 220kWh/m2

2030 targets average 0 110kWh/m2 Business as usual 2025 Targets 2030 Targets

Figure 13: Operational carbon targets

120 LETI / RIBA / UKGBC

CRREM UK 100 CRREM DK

CRREM ND 80

60 GIA/year) 2 e/m 2 40 (kgCO 2020 BAU average 20 70kgCO2e/m2 GIA/year

2030 targets average 0 30kgCO2e/m2 GIA/year Business as usual 2025 Targets 2030 Targets

Net-zero buildings Where do we stand? 19 2 Case studies summary

01. Office building – London, UK | 21

02. All electric office building – London, UK | 23

03. Complete transformation, office building – London, UK | 25

04. Refurbishment, office building – London, UK | 27

05. Mixed-use building – Copenhagen, DK | 29

06. Residential timber tower – Amsterdam, NL | 31

This section gives summary data only. For more detailed information on the case studies including key factors related to their design development the reader should reference section 4 - additional data on case studies.

Net-zero buildings Where do we stand? 20 01. Office building, London, UK

Composite concrete / steel columns

11 storeys Steel braced stability system

Exposed soffit

Post-tensioned flat slab

Services

Unitized curtain walls Reinforced Reinforced concrete basement Reinforced concrete raft and piles

Oversite development

Figure 14: Whole life carbon (A-C) TYPE Office, New build LOCATION London, UK 9% DEVELOPMENT STAGE Manufacturing and construction 62% 8% GIA 29,819 m2 RATING SCHEME LEED V4 Gold BREEAM 2014 Outstanding 2,450 TOOL OneClick LCA kgCO2e/m2 PROJECT DATA Late design stage information: cost plan, 15% drawings and specifications. Structural material quantities issued directly by contractor. Allowance made for services embodied carbon. ANNUAL ENERGY CONSUMPTION 222 kWh/m2/year

Net-zero buildings Where do we stand? 21 Main results Figure 15: Embodied carbon at practical Figure 16: Embodied carbon over the life cycle (A-C) completion (A1-A5) 6% 7% 3% 4% 39% 22% 39% 23% 545 kgCO2e/m2 935 4% kgCO2e/m2 3%

18% 21% 5% 3%

Substructure Internal walls and partitions Building services

Superstructure Internal finishes Energy and water use

Façade FF&E Site emissions

Table 3: Building system carbon framework

BUILDING STAGES

PRODUCTS CONSTRUCTION USE END OF LIFE EMISSIONS BEYOND LIFE

A1-A3 A4-A5 B1-B5 B6-B7 C kgCO2e/m2 D

Structure 240 9 6 4.1 258 -53 Substructure and superstructure

Skin 100 1 94 0.2 195 111 Façade

Space plan 39 0 39 0.2 78 -2 Partitions and internal finishes

Services Building services, energy 120 1 240 1512 1.4 1873 -56 and water use

BUILDING LAYERS Stuff Fittings, furnishings and 5 10 15 -5 equipment (FF&E)

Site emissions 30 30 Waste, electricity and fuel

Building carbon emissions Embodied and operational 503 40 388 1,512 6 2,449 -227

Net-zero buildings Where do we stand? 22 02. All electric office building, London, UK

Steel / pre-cast concrete frame

8 storeys Exposed soffit Curtain walls Steel beams and steel columns Services Precast pre-stressed concrete slab

Reinforced concrete central core Deep piles and Reinforced Reinforced concrete basement pile cap

Figure 17: Whole life carbon (A-C) TYPE Office, New build LOCATION London, UK 10% DEVELOPMENT STAGE Building’s handover 37% GIA 40,065 m2 15% RATING SCHEME LEED 2014 Gold BREEAM 2014 Excellent Ecohomes Excellent 1,650 TOOL kgCO2e/m2 OneClick LCA and Arup PECC tool 7% PROJECT DATA Late design stage information: engineers’ quantities from calculations and models and cost plan. Allowance made 6% for services embodied carbon. ANNUAL ENERGY CONSUMPTION 109 kWh/m2/year 22%

Net-zero buildings Where do we stand? 23 Main results Figure 18: Embodied carbon at practical Figure 19: Embodied carbon over the life cycle (A-C) completion (A1-A5) 4% 3% 16% 18% 24% 35%

665 7% kgCO2e/m2 1,025 kgCO2e/m2 24% 9%

37%

9% 12%

Substructure Internal walls and partitions Building services

Superstructure Internal finishes Energy and water use

Façade FF&E Site emissions

Table 4: Building system carbon framework

BUILDING STAGES

PRODUCTS CONSTRUCTION USE END OF LIFE EMISSIONS BEYOND LIFE

A1-A3 A4-A5 B1-B5 B6-B7 C kgCO2e/m2 D

Structure 392 11 0 5.0 408 -107 Substructure and superstructure

Skin 59 1 59 0.6 120 -33 Façade

Space plan 51 2 53 0.9 107 -7 Partitions and internal finishes

Services Building services, energy 120 1 240 620 1.3 981 -60 and water use

BUILDING LAYERS Stuff Fittings, furnishings and 0 0 0 0 equipment (FF&E)

Site emissions 30 30 Waste, electricity and fuel

Building carbon emissions Embodied and operational 623 44 352 620 8 1,647 -208

Net-zero buildings Where do we stand? 24 03. Complete transformation office building, London, UK

Roof cladding: laminated zinc Steel frame with concrete columns

7 storeys Precast frames mainly retained, minor strengthening Exposed Precast and lightweight soffit slab on steel deck Services Curtain walls (semi and glazed), opaque

Piled foundations and mini-piles (local reinforcement)

Figure 20: Whole life carbon (A-C) TYPE Office, Complete transformation LOCATION London, UK DEVELOPMENT STAGE 42% 19% Concept design GIA 42,776 m2 RATING SCHEME Aiming for BREEAM 2018 Outstanding 6% TOOL 1,580 OneClick LCA kgCO2e/m2 PROJECT DATA Concept design information: cost plan and drawings. Industry averages as material 8% specifications. Energy consumption predicted through building energy modelling. ANNUAL ENERGY CONSUMPTION 118 kWh/m2/year 19%

Net-zero buildings Where do we stand? 25 Main results Figure 21: Embodied carbon at practical Figure 22: Embodied carbon over the life cycle (A-C) completion (A1-A5) 5% 5% 3% 3% 19% 34% 33% 555 kgCO2e/m2 7% 910 kgCO2e/m2 2% 51% 10%

10% 13%

Substructure Internal walls and partitions Building services

Superstructure Internal finishes Energy and water use

Façade FF&E Site emissions

Table 5: Building system carbon framework

BUILDING STAGES

PRODUCTS CONSTRUCTION USE END OF LIFE EMISSIONS BEYOND LIFE

A1-A3 A4-A5 B1-B5 B6-B7 C kgCO2e/m2 D

Structure 303 5 14 2.7 326 -108 Substructure and superstructure

Skin 54 0 38 0.1 93 -21 Façade

Space plan 51 0 84 0.5 136 -3 Partitions and internal finishes

Services Building services, energy 104 1 200 670 1.0 976 -51 and water use

BUILDING LAYERS Stuff Fittings, furnishings and 4 18 21 -8 equipment (FF&E)

Site emissions 30 30 Waste, electricity and fuel

Building carbon emissions Embodied and operational 516 37 354 670 4 1,582 -145

Net-zero buildings Where do we stand? 26 04. Refurbishment office building, London, UK

Lightweight steel frame

Composite floors 9 storeys

Concrete and steel columns Exposed soffit Aluminum and stone façade

Services

RC raft and piles Reinforced Reinforced concrete basement

Figure 23: Whole life carbon (A-C) TYPE Office, Refurbishment LOCATION London, UK DEVELOPMENT STAGE Refurbishment completed 9% GIA 65% 47,264 m2 6% RATING SCHEME LEED V4 Gold BREEAM 2014 Outstanding TOOL OneClick LCA 1,515 PROJECT DATA 13% Late design stage information – cost plan, kgCO2e/m2 drawings and specifications. Structural material quantities issued by contractor as well as emissions due to site activity. Services embodied carbon calculated from quantities issued by the engineers. ANNUAL ENERGY CONSUMPTION 149 kWh/m2/year

Net-zero buildings Where do we stand? 27 Main results Figure 24: Embodied carbon at practical Figure 25: Embodied carbon over the life cycle (A-C) completion (A1-A5) 6% 7% 4% 4% 22% 38% 25%

315 kgCO2e/m2 535 3% kgCO2e/m2

7% 41% 13% 16%

4% 8%

Substructure Internal walls and partitions Building services

Superstructure Internal finishes Energy and water use

Façade FF&E Site emissions

Table 6: Building system carbon framework

BUILDING STAGES

PRODUCTS CONSTRUCTION USE END OF LIFE EMISSIONS BEYOND LIFE

A1-A3 A4-A5 B1-B5 B6-B7 C kgCO2e/m2 D

Structure 146 3 2 3.2 155 -62 Substructure and superstructure

Skin 41 0 41 0.1 83 50 Façade

Space plan 31 1 33 1.0 66 -18 Partitions and internal finishes

Services Building services, energy 67 0 134 983 0.8 1,185 -21 and water use

BUILDING LAYERS Stuff Fittings, furnishings and 3 3 6 -6 equipment (FF&E)

Site emissions 20 20 Waste, electricity and fuel

Building carbon emissions Embodied and operational 289 24 214 983 5 1,515 -155

Net-zero buildings Where do we stand? 28 05. Mixed-use building, Copenhagen, DK

Rooftop solar PV

Steel frame

6 storeys Services Hollow core prefab concrete slabs Mixed curtain walls: aluminum / steel / glazing

Automated mechanical Reinforced Reinforced concrete basement car park system

Figure 26: Whole life carbon (A-C) TYPE Mixed-use, New build LOCATION Copenhagen, Denmark 4%

DEVELOPMENT STAGE 33% Building in use 20% GIA 26,366 m2 TOOL OneClick LCA PROJECT DATA 2,080 Material quantities, transportation distances, 2 construction drawings and specifications kgCO e/m2 issued by contractor and design team. ANNUAL ENERGY CONSUMPTION 117 kWh/m2/year 21%

16%

Net-zero buildings Where do we stand? 29 Main results Figure 27: Embodied carbon at practical Figure 28: Embodied carbon over the life cycle (A-C) completion (A1-A5)

2% 10% 7% 14% 23% 3% 880 30% kgCO2e/m2 1,390 kgCO2e/m2 4% 25% 45%

31%

Substructure Internal walls and partitions Building services

Superstructure Internal finishes Energy and water use

Façade FF&E Site emissions

Table 7: Building system carbon framework

BUILDING STAGES

PRODUCTS CONSTRUCTION USE END OF LIFE EMISSIONS BEYOND LIFE

A1-A3 A4-A5 B1-B5 B6-B7 C kgCO2e/m2 D

Structure 466 13 2 22.4 504 -69 Substructure and superstructure

Skin 215 3 215 0.6 434 -197 Façade

Space plan 34 1 34 8.2 78 -12 Partitions and internal finishes

Services Building services, energy 120 1 201 692 1.7 1,009 -46 and water use

BUILDING LAYERS Stuff Fittings, furnishings and 5 24 29 -11 equipment (FF&E)

Site emissions 19 19 Waste, electricity and fuel

Building carbon emissions Embodied and operational 842 36 476 692 33 2,079 -336

Net-zero buildings Where do we stand? 30 06. Residential timber tower, Amsterdam, NL

Aluminum / glazing façade

Exposed soffit

CLT internal walls and 21 storeys glue laminated beams

CLT / concrete floors

RC concrete structure

Services

Diaphragm retaining wall

Precast reinforced Reinforced Reinforced concrete basement concrete piles

Figure 29: Whole life carbon (A-C) TYPE Residential, New build LOCATION Amsterdarm, Netherlands 4% DEVELOPMENT STAGE 54% 14% End of construction GIA 14,544 m2 RATING SCHEME BREEAM 2014 Outstanding 7% TOOL 1,440 OneClick LCA 2% kgCO2e/m2 PROJECT DATA Design information from tender documents, material quantities from 3D models. Assumptions taken for services embodied carbon (lower than for office buildings). 15% ANNUAL ENERGY CONSUMPTION 74 kWh/m2/year

Net-zero buildings Where do we stand? 31 Main results Figure 30: Embodied carbon at practical Figure 31: Embodied carbon over the life cycle (A-C) completion (A1-A5)

7% 12% 5% 8% 17% 32%

420 31% 3% kgCO2e/m2 660 4% kgCO2e/m2 44% 12%

5% 16%

Substructure Internal walls and partitions Building services

Superstructure Internal finishes Energy and water use

Façade FF&E Site emissions

Table 8: Building system carbon framework

BUILDING STAGES

PRODUCTS CONSTRUCTION USE END OF LIFE EMISSIONS BEYOND LIFE

A1-A3 A4-A5 B1-B5 B6-B7 C kgCO2e/m2 D

Structure 225 9 9 14.4 257 -105 Substructure and superstructure

Skin 51 1 51 1.4 104 -37 Façade

Space plan 28 1 16 0.7 47 -4 Partitions and internal finishes

Services Building services, energy 70 0 140 781 0.8 993 -11 and water use

BUILDING LAYERS Stuff Fittings, furnishings and 3 7 10 -2 equipment (FF&E)

Site emissions 30 30 Waste, electricity and fuel

Building carbon emissions Embodied and operational 377 41 224 781 17 1,440 -158

Biogenic carbon storage: -146kgCO2e/m2 (2116t CO2e) PV Offset: -61 kgCO2e/m2

Net-zero buildings Where do we stand? 32 3 Results and discussion

3.1 Whole life carbon analysis | 34

3.2 The role of offsetting | 45

3.3 Challenges and opportunities | 47

3.4 Where do we stand? – Conclusion | 48

Net-zero buildings Where do we stand? 33 3.1 Whole life carbon analysis

UPFRONT EMBODIED of products has a different From the case studies, we are CARBON (A1-A5) carbon impact depending on able to identify a range of results Figures 32 and 33 display the where it takes place. Case for A1-A5 which spread from embodied carbon study 05 – in addition to being 310 kgCO2e/m2 for an efficient impact at “practical completion” material intensive – is located refurbishment to 880 kgCO2e/ (modules A1-A5) in a region which has a higher m2 for a more typical building, – the end of the initial energy grid carbon factor than with an average at 560 kgCO2e/ construction phase – looking the other case studies. The m2. This demonstrates that at an average value taken material sourced locally have a 40% reduction on average across all six case studies. therefore a higher embodied compare to a BAU of 1000 carbon impact or are transported kgCO2/m2 is already achievable. As a reminder, this corresponds from a further location. to all the carbon emissions Challenge: could a 2030 associated with the Case study 04 (refurbishment) is target of 400 kgCO2e/m2 manufacturing of materials and a key example where the design (A1–A5) be set for all projects? the construction process. team collaborated with the The doughnut chart represents client to reduce the extent of the Overall, there is a need the average distribution structural works to an absolute for better clarification and per building element. minimum by undertaking in- transparency of specific depth design studies which targets related to the overall At this stage, the substructure allowed for the re-use of most decarbonization ambitions. As and the superstructure are of the existing structural frame. exemplified in case study 04, a consistently responsible for The impact of case study more collaborative approach the largest impact across 04 at practical completion is between project stakeholders all case studies. Together, 44% less than the average will support decarbonization they represent 54% of the over the six case studies. through better understanding average emissions whereas of the building design and 15% and 18% are attributed The first chapter looked at the opportunity areas and technical respectively to the façade industry's current averages and challenges. Research and and to the building services. proposed a 2020 business as development should focus usual (BAU) figure at practical on the areas with the largest The distribution per building completion of 1,000 kgCO2e/ impact to drive decarbonization element also highlights the m2. Looking at values across although smaller contributors respective impact of each the six projects, it can be seen should not be ignored. part of the value chain. Over that the BAU figure could be the first life cycle stage (A1- challenged and potentially A5), a focus on the sub and lowered, suggesting that with superstructure have the greatest an increased focus on low potential to reduce the upfront carbon design, the industry embodied carbon emissions. could aim at significantly more A1-A5 IN NUMBERS This is not to say other elements, challenging targets for 2030. • Case study results range such as façade and building This also raises the question 310-880 kgCO2e/m2 services, are not important of what actually is the baseline contributors and deserve in the WorldGBC definition • 54% substructure and attention at this stage. for embodied carbon targets. superstucture (average) In other words what are • Business as usual The results also highlight we proposing to reduce assumed benchmark that the geography is a non- by 40% by 2030? Perhaps (2020) 1,000 kgCO2e/m2 negligible parameter. The energy this target should be made • Case studies average invested in the extraction of raw more explicit and refined on 560 kgCO2e/m2 materials and the manufacturing a region by region basis? (44% reduction)

Net-zero buildings Where do we stand? 34 Figure 32: A1-A5 Average Distribution across all six case Studies

5% 11% 18% Substructure Superstructure

Façade 1% 560 Internal walls and partitions 5% kgCO2e/m2 Internal finishes 2% FF&E

Building services 15% 43% Site emissions

Figure 33: A1-A5 per case study (kgCO2e/m2)

-40% 2030 Target (?) 2030 Target Business as usual 2030 Aspiration (?) 2030 Aspiration

Case study 01

Case study 02

Case study 03

Case study 04

Case study 05

Case study 06

0 200 400 600 800 1,000

Net-zero buildings Where do we stand? 35 IN-USE AND END-OF-LIFE There is a lot of potential to Meanwhile, the IEA outlines a EMBODIED CARBON (B-C) improve this part of the WLCA; trajectory for the global CO2e Figures 34 to 37 display the the big equipment pieces may emissions emanating from the embodied carbon impact “in be designed to last longer energy sector and industrial use” and "end of life" (Modules and the façade can partially processes which suggest that B1-B5 and C1-C4) across all six be dismantled or reused emissions will have reduced by case studies. For buildings, this to avoid full replacement two-thirds by 2050.33 This could corresponds to all the carbon of the entire system. be used to estimate material emissions associated with the carbon factors in 30 years. building elements that will be The BAU figures for embodied Generally, if we are to replaced as their lifespan is carbon over life cycle stages B decarbonize this portion of the shorter than the building lifespan. and C are currently estimated WLCA, we need to optimize the to be around 300 kgCO2e/ systems to have fewer elements The doughnut chart represents m2 (see chapter 01). More to replace, use products with the average distribution across thought and rigor needs to be longer life span and apply all six case sudies per building considered in terms of this stage circular economy principles, to element. Through the in-use of the life cycle assessment. reduce the in-use embodied stage, the building services The initial design process emissions to a minimum. equipment is responsible for must better assess the future the largest impact. Building impact of the elements that Challenge: could a 2030 target services equipment represents will need to be replaced and of 0 kgCO2e/m2 (B1-C4) be 57% of the emissions, and evaluate this against better set for all projects to drive 25% is attributed to the façade established criteria and targets. innovation, better practice whereas the primary structural and circular principles? elements are designed to However, for buildings designed last the whole building life. today, the average first major replacement cycle would This also highlights the impact occur around 2050. By this of each part of the value chain stage, further supply chain EMBODIED B AND over the in-use stage. A focus decarbonization will likely C IN NUMBERS on the building services and the have occurred across all • Case study results range façade design has the greatest materials use. It is unclear at 220-510 kgCO2e/m2 potential to reduce the in use the moment how to account • 56% building services embodied carbon emissions. for this, and targets should therefore be reviewed as • Business as usual assumed Following the RICS methodology new knowledge, research, benchmark (2020) – which is the clearest WLCA and guidance emerges. 300 kgCO2e/m2 guidance published at the A better methodology to • Case studies average moment – where no specific deal with the supply chain 347 kgCO2e/m2 information is given, the life decarbonization is needed (12% higher) span of the building services which will allow the in-use and of the façade are taken embodied carbon to be EMBODIED A-C as 20 years and 30 years estimated in a consistent IN NUMBERS respectively. WLCA is still an way. The methodology should • Case study results range emerging field, and a great deal seek to define an industry- 530 – 1390 kgCO2e/m2 of work is being undertaken to wide and unified approach to • Business as usual assumed increase the amount of data supply chain decarbonization benchmark (2020) available on building services to including a verified data source 1300 kgCO2e/m2 develop a better understanding for carbon factors; a defined of their carbon impact over scope of assessment; and key • Case studies average their life span such as the enablers and interventions. 910 kgCO2e/m2 TM65 CIBSE guidance.14

Net-zero buildings Where do we stand? 36 Figure 34: B1-B5 – Average distribution Figure 35: C1-C4 – Average distribution

2% 9% 16% Substructure 57% 25% 13% Superstructure Façade 335 3% 15 Internal walls and partitions kgCO2e/m2 4% kgCO2e/m2 Internal finishes 4% FF&E

9% Building services 3% 55% Site emissions

Figure 36: A-C – Average distribution per building element

3% 7%

32%

28% 910 kgCO2e/m2

2% 6% 3% 19%

Figure 37: A-C per case study (kgCO2e/m2)

-40% 2030 Target (?) 2030 Target Business as usual 2030 Aspiration (?) 2030 Aspiration

Case study 01

Case study 02

Case study 03

Case study 04

Case study 05

Case study 06

0 200 400 600 800 1,000 1,200 1,400

A1-A5 B1-B5 C1-C4

Net-zero buildings Where do we stand? 37 OPERATIONAL Based on the targets described the aspirational target levels), CARBON (B6-B7) in chapter 01, the industry is the benchmark converts The graphics display the pushing to lower office buildings' the EUI in carbon equivalent operational carbon impact in-use energy use to 75kWh/m2. This emissions based on the current across all six case studies. As represents a 65% reduction UK grid BEIS factor.13, 16 a reminder, this corresponds compared to 2020 BAU. It can The case study results adopt to the carbon emissions be seen that the case study national grid carbon factors associated with all the energy estimated EUI are in some cases amended to the geographical and water needed to operate getting closer to the 2030 context of the case study. the building over its 60 years targets but much progress is still On average, it appears lifespan (module B6, B7). needed. All these case studies operational emissions are close to practical completion are responsible for 1,860 The first bar chart illustrates the or already completed, except kgCO2e/m2, not accounting annual energy consumption case study 03, which might for decarbonization and of each project accounting reach practical completion in 870 kgCO2e/m2, accounting for regulated and unregulated 2025. This is reinforcing that we for decarbonization over loads in kWh/m2. This is easier need to be able to design for the a 60 year building life. to assess as it removes a 2030 targets by 2025 the latest. layer of assumptions taken Are maximum EUI targets being on the grid’s carbon factor. To achieve the required levels established regionally for all of decarbonization we will need countries? Are they aligned with It can be seen that the case to design buildings to be much national grid decarbonization studies typically perform better more energy efficient than we are trajectories? Do they represent than the current BAU for office currently to provide the energy sufficient demand reduction to buildings, estimated at 220 kWh/ that is required via clean, zero- match clean supply potential?33 m2 (REEB/RIBA benchmarks carbon supplies. It may also be described in chapter 01). Note necessary in terms of achieving These questions need to be that case study six is a residential the required demand levels to addressed collaboratively by building and belongs to a change the expectations of the industry to help shaping different benchmark (150kWh/ the occupants as to the level realist targets aligned with the m2 REEB/RIBA benchmarks). of environmental conditioning remaining carbon budget. they can always assume. The enregy use intensity is typically estimated using More work is required to advanced energy modelling validate the setting of energy tools and benchmarks. The use (demand) targets that are energy consumption of case aligned with regional supply grid OPERATIONAL B study 05 was measured via the decarbonization in order that IN NUMBERS use of actual energy bills since we better understand where we • Case study results range the building has been in use sit in terms of genuine net-zero 110-220 kWh/m2 for for two years. In this particular carbon operation trajectories. offices 75kWh/m2 for case, it is interesting to observe residential that the actual demand was Figure 39 estimates the • Business as usual actually 50% lower than originally equivalent operational carbon benchmark (offices) estimated. This highlights (kgCO2e/m2/year) in three key 220kWh/m2 the difficulties to accurately scenarios: 2020 grid factor; • Target 2030 foresee the operational carbon 2030 grid factor projection; 75 kWh/m2 emissions and the need to and as an estimated average measure continually the energy over the next 60 years. To set • Case studies average consumption of our buildings the benchmark for comparison 140kWh/m2 (offices only): to gather better data. (e.g. the BAU baseline and +87%

Net-zero buildings Where do we stand? 38 Figure 38: Energy use intensity (kWh / m2 / year)

222

Business as usual

-65% 149

118 117 109

2030 target

Case study 01 Case study 02 Case study 03 Case study 04 Case study 05 Case study 06

Figure 39: Operational carbon – kgCO2e / m2 / year

2020 grid factor 2030 grid factor estimate Estimated average over the next 60 years 51 Business as usual

Demand reduction Grid decarbonization Grid decarbonization -65%

34 31 27 25 25 24 25 20

15 16 16 14 14 13 10 11 11

Case Case Case Case Case Case Case Case Case Case Case Case Case Case Case Case Case Case study study study study study study study study study study study study study study study study study study 01 02 03 04 05 06 01 02 03 04 05 06 01 02 03 04 05 06

Net-zero buildings Where do we stand? 39 WHOLE LIFE CARBON (A-C) A wider, easily-accessible data Figure 39 and 40 display set is required is required in A-C IN NUMBERS the whole life carbon impact order to establish clear targets • Case study results range looking at all six case studies. in terms of demand reduction 1,440 to 2,450 kgCO2e/m2 both from and embodied and • Average breakdown As reminder this accounts for operational carbon perspective. across all six case both embodied and operational However these few studies studies carbon from stages A to C perhaps point to possibilities in 32% A1-A5 over a 60 year building life span. terms of raising our immediate 19% B1-B5 and C Some of the projects presented sights and establishing clearer 49% B6-B7 here are innovative and and more widely ambitious • Case studies average represent a growing focus targets going forwards. 1,790 kgCO2e/m2 on low carbon designs. (30% reduction) Challenge: could a maximum 2030 target of less than 1,000 kgCO2e/m2 (A-C) be set for all projects?

Figure 40: Case studies results

Case Study 01 Case Study 02 Case Study 03

22%

37% 41% 42% 35% 2,450 1,650 1,580 kgCO2e/m2 kgCO2e/m2 kgCO2e/m2 16%

22% 23% 62%

Case Study 04 Case Study 05 Case Study 06

65% 21% 33% 42% 29% 54% 1,515 2,080 1,440 kgCO2e/m2 14% kgCO2e/m2 kgCO2e/m2

17%

25%

Net-zero buildings Where do we stand? 40 Setting up explicit targets will Figure 41: Whole life carbon (A-C) average across all six case studies contribute to drive the required immediate decarbonization of all future building projects towards 32% much more ambitious outcomes. 49%

Based on growing a better understanding and focus on 1,790 CO2e/m2 whole-life decarbonization kg could we imagine figure 42, representing an aspirational maximum carbon footprint 19% target for all buildings being delivered in 2030? Is this too much of a stretch and if so why?

Can we design all future Figure 42: Whole life carbon (A-C) aspirational performance by 2030 projects to avoid any further carbon emissions are required during their life span (B1-B5) via adopting genuine circular 50% economy principles? 50% <1,000 Clearly the whole industry kgCO2e/m2 must come together and work collaboratively to achieve the desired ultimate outcome of decarbonising all elements of the 0% built environment and to do this we need clear and unambiguous objectives and targets.

Figure 43: A-C per case study (kgCO2e/m2)

Case study 01

Case study 02

Case study 03

Case study 04

Case study 05

Case study 06

0 500 1,000 1,500 2,000 2,500

Embodied A1-A5 Embodied B-C Operational B6-B7

Net-zero buildings Where do we stand? 41 BEYOND BUILDING LIFE (D) This valuable as currently the represents about 38% of the Figure 44 and 45 display the demand for steel far outstrips upfront embodied carbon stage D emissions looking the availability of scrap. emissions. Figure 45 show the at all six case studies. As a A-D total carbon impact for each reminder this represents the Timber different end of life case study. Although stage D potential benefits (or loads) scenarios need to be considered reduction is not negligeable, it associated with the material carefully at the outset of a doesn’t by itself provide carbon to serve a purpose beyond project. Timber placed in landfill return on our investment. the 60 years life cycle. to decompose emits methane, As circular economy principles this has a further detrimental are starting to emerge for the It is not included in the scope carbon emission impact. On building industry, Module D will of WLCA, often owing to the the other hand, timber can be have increasing importance in difficulty in drawing assumptions reused as a product, incinerated the WLCA process and materials post the end of the building’s life. or used as biomass to create will have a growing potential for However, it is potentially non- energy in which cases the reuse without being downcycled. negligible and the impacts and carbon initially sequestered benefits can appear significant in the trees is stored longer especially in regard to metals or serve a new purpose STAGE D IN NUMBERS and biogenic materials. beyond the buildings life. • Case study results range Figure 44 illustrates the -150 to -340 kgCO2e/m2 Steel can be 100% recycled and reduction – averaged across • Case studies average represents a benefit for future the six case studies – in WLCA -210 kgCO2e/m2 projects which can be procured emissions that would appear • 35% superstructure and with recycled steel, lowering if stage D was theoretically 35% façade their upfront carbon impact. accounted for. This number

Figure 44: Stage D – Average distribution

19% 4% Substructure

Superstructure

Façade -210 Internal walls and partitions kgCO2e/m2 35% Internal finishes

FF&E

Building services

35%

RESULTS SUMMARY carbon is now estimated to be context of the climate emergency Figure 46 demonstrates approximatively 50% of the life - we are all faced with - are the total distribution of cycle emissions of a building released in the short term with carbon emissions over the which clearly further emphasises currently little focus on real global six case studies throughout the importance of addressing abatement. Without question, we the building’s life cycle. embodied carbon now. must reduce these emissions.

Over the past decade, design The WLCA graphic presented However, the case studies teams have focused mainly in time domain highlights the also show on average on reducing the operational significance of the A1-A5 70% of the average WLCA, carbon emissions associated emissions. These immediate using current assumptions with the building sector. On embodied carbon (construction) and methodologies, will average, the case studies emissions represent on average be emitted during the life demonstrate that the embodied 30% of the WLCA and in the time of the buildings.

Net-zero buildings Where do we stand? 42 Figure 45: Whole life carbon – A-D (kgCO2e / m2)

Case study 01

Case study 02

Case study 03

Case study 04

Case study 05

Case study 06

0 500 1,000 1,500 2,000 2,500

Embodied A1-A5 Embodied B-C Operational B6-B7 Whole life A-D Embodied D

Figure 46: Whole life carbon emissions through time – average distribution

580 50%

50% 480

380

280 2 /m 2e

KgCO 180

80 Construction A1 – A5 B4 – FF&E Replacement B4 – Services + FF&E Replacement + Partitions + Façade B4 – Structure Replacement B4 – Services + FF&E Replacement B4 – FF&E Replacement C1 – C4 End of life

0 0 10 20 30 40 50 60 YEARS

-120 Beyond life D life Beyond

In Use B6 – B7

-220

Operational carbon Embodied carbon

Net-zero buildings Where do we stand? 43 BIGGEST CONTRIBUTING with all other residual emissions reinforcement, and glass MATERIALS comprising 6% of the footprint. account for approximately 60% The first graphic summarizes the The second graphic highlights of overall A1-A3 emissions. highest contributing materials the average most contributing The timber within the building to the overall embodied carbon materials to the overall accounts for approximately 10% footprint across the first five embodied carbon of case of the embodied carbon total. case studies. Together, steel, study six – a residential timber The contribution of services concrete, aluminum, steel building. The average material to embodied carbon accounts reinforcement, glass, and raised contribution deviates from for approximately 20% with floor account for approximately the other case studies owing all other residual materials 75% of the overall A1-A3 to the timber frame rather comprising 10% of the footprint. emissions. The contribution of than the mixed concrete and services to embodied carbon steel frame. Together, steel, accounts for approximately 20% concrete, aluminum, steel

Figure 47: Total tCO2e per material across the first five case studies

Steel Concrete Services Aluminum All Other 32% 22% 20% 9% Materials 6%

- Glass Raised 4% Floor 3% Reinforce ment Steel 4%

Figure 48: Total tCO2e per material for case study 06 – Residential timber building

Concrete Services All Other Steel 33% 19% Materials 10% 12%

Timber

9% Reinforcement Steel 8% Aluminum 6%

Glass 4%

Net-zero buildings Where do we stand? 44 3.2 The role of offsetting

Currently carbon offsetting within the International Carbon early in the introduction needs plays a role in the achievement Reduction and Offset Alliance.30 for all reasonable approaches of most global carbon-neutral Types of investment projects towards reducing embodied and net-zero commitments. include afforestation, direct and operational carbon to have At present there is a lack of a air capture with carbon been rigorously exhausted unified and precise definition and storage, renewable energy, before offsets are considered. accountability in relation to valid and community initiatives. In offsetting for both terminologies. the current offsetting market The diagram below provides (e.g. Gold Standard) credits an indicative outline of the In fact, when it comes to net zero, could be purchased to offset whole-life carbon emissions the prefix “net” implies some business as usual carbon associated with a typical form of balancing of the emitted outcomes for as little as 1% of buildings’ projects in line with carbon. Various organizations the total construction cost. a timeline for the hypothetical and institutions, such as the corresponding offsets. Science Based Target Initiative The primary aim of the (SBTi) and the University of industry needs to be to focus It seems clear that more Oxford on behalf of the Race To on widescale, systematic rigor is urgently needed in Zero, are working toward creating reduction as a priority if we are verifying acceptable levels clarity of the net zero definitions, to achieve the global emissions and processes for adopting terminologies and its application reductions needed. Hence the offsets before making any toward net zero claims. strategic hierarchy discussed claims, especially for net zero.

Agreement is mounting Figure 49: Whole life carbon emissions, Arup (2020)16 toward a firm emphasis of

mitigation first, followed by refurbishment Replacement and disposal Demolition and Construction Operation Operation Material re-use how much and when carbon products and can be compensated (residual processes emissions) and what type of “offsets” are allowed to be used.

The six case studies presented here demonstrate an average s upfront embodied carbon of n o i s s 560 kgCO2e/m2 and a whole i m e

life cycle carbon footprint n o b of around 1800 kgCO2e/m2, r e c a hence for any of these buildings f i l

to hypothetically claim to be o l h net-zero now, some offsetting W Time would need to be employed.

Currently building projects make use of offsetting by either direct procurement (using energy from clean, renewable sources) or by purchasing equivalent carbon credits from a recognized 27 emissions reduction scheme. t f s e o f Several internationally recognized n o and certifiable schemes exist, r b 29 a including the Gold Standard, C and those recognized schemes Client / Developer Designer Contractor Net-zero buildingsUser Where do we stand? 45 Operator / FM CARBON SEQUESTRATION – END OF LIFE PAYBACK – ON SITE RENEWABLE ENERGY CASE STUDY 06 EXAMPLE CASE STUDY 06 EXAMPLE – CASE STUDY 06 EXAMPLE To explore the practical By considering the benefits In figure 52, operational carbon implications of sequestration associated with the Beyond (B6) over the building life cycle (locking carbon into a system) as Building Life (module D), a carbon is compared against operational a form of offsetting, case study “payback” of 24% is calculated carbon accounting for on-site six presents a useful example. for this case study (figure 51). renewable energy generation.

Figure 50 outlines case Incorporating the potential Renewable energy presents a study six's embodied of re-use/ repurposing of widely recognized approach to carbon (A1-A5) at practical the building’s systems and carbon neutralization through completion. Where carbon materials within WLCA should clean energy generation and sequestration is accounted be explored and verified more procurement. For case study for, the embodied carbon is thoroughly. If not included in six, on-site renewable energy approximately 35% lower than the WLCA scope, should it be generation accounts for an 11% excluding sequestration. seen as a sort of offset? Can carbon saving. As the global Whilst widely neglected from the industry as a whole set the energy mix transitions towards many international life cycle direction for a circular economy a decarbonized future, carbon assessments, ‘climate-friendly’ of components whereby genuine offsetting should consider timber construction may prove whole scale payback is achieved, changes in the energy mix and a useful incentive for improved and would this ultimately benefit priority/ viable energy sources carbon sequestration in forests the overall road to net-zero? as a means of offsetting. through regenerative forest Contributions should consider management practices that wider parameters needed for a exceed best practice.32 Could renewable transition including the inclusion of biogenic carbon research and technologies, steer the industry towards emerging energy sources. regenerative and natural cycles as a means of investment?

Figure 50: Embodied carbon at Figure 51: Whole life embodied Figure 52: Operational carbon practical completion (kgCO2e/m2) carbon results (kgCO2e/m2) (kgCO2e/m2)

418 659 763

-35% -24% -11% 677 501 272

A1-A5 A1-A5 A-C A-D With With Total without Total with Without beyond With beyond decarbonization decarbonization sequestration sequestration life benefit life benefit accounting for PVs

The three graphs highlight the A clear methodological Offsetting approaches must lack of clear and consistent approach and appropriately be regularly reviewed to approach to direct offsetting determined Module boundary support the development related to buildings. In the short must be set for these types of the market for carbon term, the industry must focus of carbon compensation to neutrality, account for on accelerating and sharing ensure that valid reductions technological developments, knowledge on the benefits are accounted for at the and climate mitigation goals. of emissions reductions appropriate project stage, and and emissions removals the right decisions are made via the methods above. to drive lowest carbon design.

Net-zero buildings Where do we stand? 46 3.3 Challenges and opportunities

Challenges Opportunities

• Small number of completed WLCA – all • Growing awareness and industry projects should commit to WLCA with engagement, collaboration and partnerships performance measurements • Increased importance within sustainability • Incentives for client/developer to drive certifications and rating schemes reductions and how to encourage end user • Regulatory and financial trends for buildings behavioral change within buildings Incentive decarbonization in line with sustainable • Aligning international strategies, policies finance mechanisms and legislative guidance • Challenging brief, need and design criteria at • Commitment to reduce buildings carbon early stage footprint

• Definition of net-zero for the building asset • Organizations such as SBTi, WorldGBC and still unclear WBCSD collaborating toward answers • Clarity if current buildings impact for • Emerging benchmarks – need for transparent different typologies and in different regions Net-zero for assumptions for the data to be valid • Clarity on targets relative to a baseline or the building • Emerging industry accepted targets absolute asset • Industry working together to ensure the • Role of carbon offsetting: what type, when, validity and transparency of offsetting how much schemes

• Common scope and methodology • Adopting and embedding common • Plethora of WLCA tools exist with differing methodologies methodological assumptions • Development of efficient tools and Approach • Transparency on assumptions technologies including digital innovation • Industry is challenged to share openly data

• Efficiently gathering all relevant project data: • Digitalization of data collection and work-flow material quantities and specifications of all optimization building elements • Manufacturers producing and sharing EPDs • Availability and transparency of embodied • Low carbon materials progress through carbon factor data per region research and innovation Embodied • Understanding of material decarbonization • Circular economy implementation and for the main material contributors carbon business models within the supply chain, • Clear measures to be identified on how to prioritizing reused and recycled materials drive reduction needed at all project life • Dematerialization and designing efficient and cycles long-lasting systems

• Accurately assessing operational carbon • Growing initiatives to measure and compare • Estimating energy grid decarbonization environmental performances (e.g. Nabers) Operational • How to reduce the demand in energy of • New technologies, research, and multi-storey buildings carbon development

• Lack of knowledge sharing • Growing acknowledgement of importance of • Accounting for geographical and WLCA and further research needed jurisdictional variations in approach, • Behavioral change and effectively limitations, and technical constraints Industry communicated systems thinking approach to • Clearly understanding the synergies and collaboration allow flexibility to change challenges between decarbonization and • International engagement at events such as other key sustainability disciplines the COP26

Net-zero buildings Where do we stand? 47 3.4 Where do we stand? CONCLUSION

The decarbonization of the built as all have had some form of Considering this quantum of environment is integral towards sustainability or low carbon building construction in the the attainment of the IPCC agenda from their outset as context of the case results 1.5°C scenario. Representing detailed in the individual case of this report we gain insight nearly 40% of all global energy- studies. However, we would also into the urgency associated related carbon emissions, the argue these projects could do with challenging ourselves building sector needs to be a better with even more focus on all together as an industry to significant part of a clear and achieving the absolute minimum rapidly and significantly reduce absolute pathway towards carbon footprint possible. both embodied and operational overall decarbonization. carbon emissions. As a facilitator Recent GlobalABC status reports of this reduction we need to Although the six case studies for the building and construction collaborate more widely to gain represent a small sample from industry have pointed to there widespread, data-informed, Northern Europe, the findings being a current global cumulative WLCA understanding, and provide an indicative picture building floor area of circa 250 from this informed position of the industry’s current billion m2 and that this number develop credible and impactful performance and challenges, is forecast at current population reduction strategies. identifying opportunities for the growth estimates to rise to circa sector’s journey toward net zero. 415 billion m2 by 2050.3,5 At present there are clearly This is an average annual growth barriers to accurately and The projects chosen could of over 5 billion m2/year. consistently assessing arguably be representative of carbon intensity data the better end of the spectrum both from an embodied in terms of overall building WLCA (construction) and operational (energy use) perspective in all building projects.

Figure 53: Past and future global annual carbon emissions (Mt) from the energy sector and industrial processes. Our World in Data, Global ABC/IEA/UNEP and IEA (2020) 3, 6, 33 In 2019, Buildings contributed to 38% of emissions: 13,850Mt 40,000

35,000

30,000

25,000

20,000

15,000

10,000

5,000

1870 1890 1910 1930 1950 1970 1990 2010 2030 2050

Net-zero buildings Where do we stand? 48 There is a current lack of Properly focused collaborative we are contributing to wider available carbon intensity research, technology, knowledge sharing on the and WLCA data as well as a and innovation will drive route to net-zero buildings. general lack of wide scale decarbonization. The report By working collaboratively as resource, collaboration and points to the main material an industry toward the same knowledge sharing in this field. and systems contributors goal we can drive our projects to building whole life carbon to achieve the required level There is also a lack of global and highlights the benefits of of decarbonization that the consensus on methodological consumption reduction and planet needs. To do this we assumptions and definitions the development of lower must consider the whole life of net-zero proportionate carbon materials, improved cycle and value chain in an to required GHG emissions reusability and recyclability. open and honest way and share reductions, removals, offsetting generously our knowledge, and established explicit Additionally, we need to explore insight, and success stories to targets to support this. These the opportunity to simplify promote industry-wide learning barriers need to be addressed the comparison between new and rapid advancement. rapidly at scale if we are to built vs retrofit. Adopting the have the impact we need. same embodied carbon target From this point forward will create a strong incentive we must aim to drive The case studies highlight towards renovation as this transformation across every key opportunity areas for starts with a clear advantage project we undertake. decarbonization through in terms of upfront carbon Based on this work we call on growing partnerships and (A1-A5) (see case study 04). companies from across the industry collaboration; an built environment and around industry-wide call for accepted By using more case studies the globe to conduct whole life targets and methodologies; as a lens for interrogation, we carbon assessments of their and emergent regulatory and can gain insight into current projects as a matter of course, financial trends for incentivizing and future challenges and openly publishing the results the low carbon transition. opportunities within the in view of building a body of buildings sector. By sharing evidence and shared learning. our case study work we hope

The building industry must now for globally each year. KEY ACTIONS FOR come together and commit By setting clear targets as DECARBONIZATION to measuring the whole life discussed in this report we • Commit to WLCA on all carbon emissions associated can halve both the embodied projects with all future projects in a and operational carbon in • Develop consistent clear and transparent way buildings. The numbers and transparent carbon demonstrated here. If we in this report show that intensity and benchmark start to systematically collect this goal can be within our data and use this information reach. This would in turn • Adopt explicit targets at the beginning of each make it possible to halve our project, then we can achieve emissions in the next decade, • Define net-zero buildings an immediate cut in the an act that will genuinely put • Establish wider 14 gigatonnes of carbon us on track towards a net- collaboration this industry is responsible zero built environment.

Net-zero buildings Where do we stand? 49 4 Additional data on case studies

01. Office building – London, UK | 51

02. All electric office building – London, UK | 59

03. Complete transformation, office building – London, UK | 67

04. Refurbishment, office building – London, UK | 75

05. Mixed-use building – Copenhagen, DK | 83

06. Residential timber tower – Amsterdam, NL | 91

Net-zero buildings Where do we stand? 50 01. Office building, London, UK

Type Description Office, New build • 11 storeys office building (retail at • Exposed soffit and services – no ground floor) false ceiling • Oversite development – highly • Fully serviced with lift (cooling, Location constrained environment heating, ventilation, electricity, London, UK • Composite steel/concrete water, lighting, sprinkler) superstructure – Cooling provided by water Development stage cooled chillers and distribution Manufacturing and construction – Post tensioned flat slab 9x9m grid and 6m perimeter grid by fan coil systems – Composite columns – fabricated – Heating and hot water by natural GIA 2 steel hollow sections filled with gas boiler and distribution by fan 29,819 m concrete coil systems – Steel braced stability system – LED lighting system with daylight Rating scheme dimming City center LEED V4 Gold • Reinforced concrete basement – 2 – Server rooms (data center) BREEAM 2014 Outstanding levels – 2m raft foundation slab Tool – Secant pile walls + lining wall OneClick LCA • Main façade systems – Unitized curtain walling systems Project data – glazing and stone/metal partial Late design stage information: cost cladding plan, drawings and specifications. – Shop front – glazed stick system, Structural material quantities issued aluminum/steel frame directly by contractor. Allowance made for services embodied carbon.

Net-zero buildings Where do we stand? 51 Key embodied CO2e

Material quantities and carbon factors

Ready-mix concrete • Ready-mix concrete, RC 35/45 (32/40 MPa), (16,710m3) 50% average cement replacement with blast furnace slag (GGBS) • ICE database V3

• Carbon factor: 0.095 kgCO2e/kg

Structural steel sections and plates • Structural steel profiles, generic, (890 t) 20% recycled content, I, H, U, L, and T sections • OneClick LCA database

• Carbon factor: 2.51 kgCO2e/kg (This is close to British steel value for open

sections of 2.45 kgCO2e/kg)

Aluminum sheets and profiles • Aluminum sheet, 2700.0 kg/m3 and Aluminum (247 t) linear profiles for ceiling decoration/ cladding • Database: OKOBAUDAT 2017 and EPD SAS System 740

• Carbon factor: 10.62 kgCO2e/kg and 8.46 kgCO2e/kg

Steel reinforcement • Reinforcement steel (rebar), generic – (1,700 t) 97% recycled content (typical for UK) • Database: OneClick LCA

• Carbon factor: 0.5 kgCO2e/kg

Raised access floors • Raised access flooring system, (15,350m2) 60 – 380mm variable height, 26 kg/m2 • Database: EPD Kingspan RG3 Europe

• Carbon factor: 43.4 kgCO2e/m2

Services: Heating, cooling, ventilation, electricity, • Average impact per m2 GIA of the different systems lighting, distribution systems, lifts and others. based on past studies • Database: OneClick LCA

• Carbon factor: 10 – 30 kgCO2e/m2/system

• Total services: 120 kgCO2e/m2

Net-zero buildings Where do we stand? 52 01. Office building, London, UK

Key operational CO2e

Energy and water Figure 54: Energy consumption by activity consumption TM54 assessment: In 34% depth operational energy performance evaluation taking in account regulated and unregulated emissions.

Annual energy consumption:

222kWhequivalent/m2(GIA) 12% 13% *This includes a reduction of approximatively 0.5% of the electricity needs provided by 250m2 of PV panels.

84% electricity / 16% natural gas 8% 9%

Grid carbon factor (SAP 10) • Electricity: 0.233 kgCO2e/ 2% 8% kWh (SAP10) and decarbonization progressions 9% based on FES “steady progression” scenario 1% 4% • Natural gas: 0.21 kgCO2e/ kWh Interior lighting Small power Annual water consumption Lifts Space heating 0.35m3/m2 Domestic hot water Space cooling Carbon factor: Heat rejection Fans and pumps • Tap water, clean – Thames Water Utilities Ltd: Data center Kitchen

0.001 kgCO2e/m3 * Data center accounts for potential server rooms

Net-zero buildings Where do we stand? 53 Results

Breakdown of carbon emissions per building element

Figure 55: Embodied carbon at practical Figure 56: Embodied carbon completion (A1-A5) over the life cycle (A-C) 6% 7% 3% 4%

39% 22% 23%

545 kgCO2e/m2 935 4% kgCO2e/m2 3% 39%

18% 21% 5% 3% Figure 57: Whole life carbon (A-C) 9% 62% 8% Substructure

Superstructure

Façade

Internal walls and partitions 2,450 Internal finishes FF&E kgCO2e/m2 Building services

Site emissions

15% Energy and water use

Net-zero buildings Where do we stand? 54 01. Office building, London, UK

WBCSD Building System Carbon Framework

Case Study 01 Building Stages

Product Construction Use End of life Beyond Life Whole life carbon emissions A-C kgCO2e/m2 Emissions A1-A3 A4-A5 B1-B5 B6-B7 C D

Substructure – RICS Level 1 Foundations, lowest floor 36 3 0 1.1 39 -5 construction, retaining walls

Structure – RICS Level 2.1 – 2.4 204 6 6 3.0 219 -48 Frame, floors, roofs and stairs

Skin/Façade – RICS Level 2.5 – 2.6 100 1 94 0.2 195 -111 External walls, windows and doors

Space Plan – RICS Level 2.7 – 2.8 16 0 16 0.1 32 -2 Internal walls, partitions and doors

Space Plan – RICS Level 3 23 0 23 0.0 46 0 Internal finishes Building layers

Stuff – RICS Level 4 5 0 10 0.0 15 -5 Fittings, furnishings and equipment

Services – RICS Level 5 120 1 240 1,512 1.4 1,873 -56 Building services

Site emissions (A5) 30 30 Waste, electricity and fuel

Embodied carbon emissions 503 40 388 6 937 -227

Operational carbon emissions 1,512 1,512 Energy and water use

Building carbon emissions 503 40 388 1,512 6 2,449 -227

Net-zero buildings Where do we stand? 55 Project strengths Figure 58: Carbon emissions at practical completion (kgCO2e/m2 GIA) • Embodied carbon tracking from stage 2 to construction stage 1,000 • System optimization:

maximum efficiency of -45% structural/façade systems • Ex: Post-tensioned slab minimized use of reinforced concrete, pile diameter -40% reduced and simplified façade systems (change in panel sizes – decrease in framing) 608 544 • Cement replacement: High -10% percentage of GGBS • Dematerialisation: no false ceilings • (exposed structural slab soffit), removing external blinds • Coordination between disciplines: holistic carbon approach • Selection of products and materials based on their carbon footprint - Ex: Rock fibre insulation

chosen versus glass Business Stage 2 Stage 5 fibre and laminated glass as usual Baseline Construction partition walls instead if steel reduced material use • Polyester powder coating versus anodized aluminum everywhere possible This project demonstrated This is good but does not align • 250m2 PV panels (operational advanced consideration of with the 40% reduction target carbon) embodied carbon from the presented in the first section earliest stage onwards. The of this report. However, in total embodied carbon at comparison with the “business practical completion is 544 as usual” benchmark for an

kgCO2e/m2, this represents a office building (~1,000 kgCO2e/ 10% saving in comparison with m2), it does represent a 40% the stage 2 baseline. saving.

Net-zero buildings Where do we stand? 56 01. Office building, London, UK

Figure 59: Whole life carbon emissions

20 38%

62%

In Use B6 – B7

10 e 2 tCO 3 10

5 Construction A1 – A5 B4 – FF&E Replacement B4 – Services + FF&E Replacement + Partitions + Façade B4 – Structure Replacement B4 – Services + FF&E Replacement B4 – FF&E Replacement C1 – C4 End of life

0 0 10 20 30 40 50 60 YEARS Beyond life D life Beyond

-5

Operational Carbon Embodied Carbon

Net-zero buildings Where do we stand? 57 WLCA summary (kgCO2e/m2) Figure 60: WLCA summary (kgCO2e/m2)

544 22% Embodied (A1 – A5)

1,512 62% Operational

394 16% Embodied (B-C)

Embodied carbon

At practical completion – 16’210 tCO2e

Over the life cycle – 27’950 tCO2e

Operational energy Over the life cycle – 45’100 tCO2e

WLCA – 73’050 tCO2e

Net-zero buildings Where do we stand? 58 02. All electric office building, London, UK

Type Description Office, New build • 8 storeys office building • Façade • Reinforced concrete and steel – Some retrained façade elements Location structure (conservation principles) London, UK – One way spanning precast – Existing steel and concrete – prestress concrete slab (100mm locally reinforced – framed fixed Development stage + 50mm topping) on steel beams to new steel frame Building’s handover and steel columns – grid 6m x – New façade: precast concrete 9m (perimeter 4.5m) frame GIA – Stability: Reinforced Concrete – New curtain walling and brick 40,065 m2 central core (250-300mm thick work at base level walls) cantilevering from the piled • Exposed soffit and services Rating scheme foundations • Fully serviced with lift (cooling, LEED 2014 Gold • Foundations and reinforced heating, ventilation, electricity, BREEAM 2014 Excellent concrete basement – 1 level water, lighting, sprinkler) and server Ecohomes Excellent – Retaining wall rooms (data center) – Suspended RC basement slab • City center – highly constrained Tool (~300mm) environment OneClick LCA and Arup PECC tool – Deep piles and pile cap (~2m)

Project data Late design stage information: engineers’ quantities from calculations and models and cost plan. Allowance made for services embodied carbon.

Net-zero buildings Where do we stand? 59 Key embodied CO2e

Material quantities and carbon factors

Ready-mix concrete • Ready-mix concrete, RC 35/45 (32/40 MPa), (25,710m3) 30% Cement replacement with fly ash • ICE Database V3

• Carbon factor: 0.13 kgCO2e/kg

Structural steel sections and plates • Structural steel profiles, generic, 20% (2,920t) recycled content, I, H, U, L, and T sections • OneClick LCA database

• Carbon factor: 2.51 kgCO2e/kg (This is close to British steel value

for open sections of 2.45 kgCO2e/kg)

Laminated raised access floor • Raised access flooring system – (29,160m2) RG2 Europed (Kingspan) • OneClick LCA database

• Carbon factor: 40.3 kgCO2e/m2

Steel reinforcement • Steel reinforcement (generic – 97% recycled) (180m3 – 1405t) • One Click LCA database

• Carbon factor: 0.5 kgCO2e/kg

Aluminum / glass curtain walls • Aluminum mullion-transom system (13,420m2) and insulating double-glazed units • Database: Okobaudat and Vetrotech EPD

• Carbon factor: 9.9 kgCO2e/m2 and 87.5 kgCO2e/m2

• Carbon factor: 10 – 30 kgCO2e/m2/system

• Total services: 120 kgCO2e/m2

Net-zero buildings Where do we stand? 60 02. All electric office building, London, UK

Key operational CO2e

Energy and water Figure 61: Energy consumption by activity consumption TM54 assessment: In 31% depth operational energy performance evaluation taking in account regulated and unregulated emissions.

Annual energy consumption: 109kWh/m2(GIA) 25% 100% electricity

Grid carbon factors:

• Electricity: 0.233 kgCO2e/ kWh (SAP10) and 8% 16% decarbonization progressions based on FES “steady progression” scenario

Annual water consumption 5% 0.40m3/m2 10% 1 4% Carbon factor: % • Tap water, clean – Thames Water Utilities Ltd: Lighting Equipment 0.001 kgCO2e/m3 Lifts and Escalators Heating and Hot Water

Cooling Fans and Pumps

Catering Data Center

* Data center accounts for potential server rooms

Net-zero buildings Where do we stand? 61 Results

Breakdown of carbon emissions per building element

Figure 62: Embodied carbon at practical Figure 63: Embodied carbon completion (A1-A5) over the life cycle (A-C) 4% 3% 16% 18% 24% 35%

665 7% kgCO2e/m2 1,025 kgCO2e/m2 9% 24%

37%

9% 12%

Figure 64: Whole life carbon (A-C)

10%

37% 15% Substructure Superstructure

Façade

Internal walls and partitions 1,645 Internal finishes FF&E kgCO2e/m2 Building services 7% Site emissions

Energy and water use

22%

Net-zero buildings Where do we stand? 62 02. All electric office building, London, UK

WBCSD Building System Carbon Framework

Case Study 02 Building Stages

Product Construction Use End of life Beyond Life Whole life carbon emissions A-C kgCO2e/m2 Emissions A1-A3 A4-A5 B1-B5 B6-B7 C D

Substructure – RICS Level 1 Foundations, lowest floor 152 7 0 3.2 162 -14.9 construction, retaining walls

Structure – RICS Level 2.1 – 2.4 240 4 0 1.8 246 -92.2 Frame, floors, roofs and stairs

Skin/Façade – RICS Level 2.5 – 2.6 59 1 59 0.6 120 -33.1 External walls, windows and doors

Space Plan – RICS Level 2.7 – 2.8 6 0 6 0.2 13 -1.7 Internal walls, partitions and doors

Space Plan – RICS Level 3 45 1 46 0.7 94 -5.7 Internal finishes Building layers

Stuff – RICS Level 4 0 0 0 0.0 0 0 Fittings, furnishings and equipment

Services – RICS Level 5 120 1 240 619 1.3 981 -60 Building services

Site emissions (A5) 30 30 Waste, electricity and fuel

Embodied carbon emissions 623 44 352 8 1,027 -208

Operational carbon emissions 619 619 Energy and water use

Building carbon emissions 623 44 352 619 8 1,647 -208

Net-zero buildings Where do we stand? 63 Project strengths Figure 65: Carbon emissions at practical completion (kgCO2e/m2 GIA) • Operational energy performance - Low energy consumption 1,000 • 100% electric building: carbon emissions associated with -33% operational energy – 619 kgCO2e / m2 • Material selection - Low embodied carbon for concrete with fly ash 623 replacement – 40% - Low embodied carbon product selection for finishes: gypsum plasterboard, paint, ceramic tiles - Low embodied carbon blockwork - Prioritisation of timber framing against steel for internal walls • Dematerialization - Less dense blockwork heavy partitions with design development (-4,000m2) - No false ceiling Business As built as usual

This project demonstrated This highlights the needs to advanced consideration focus efforts on reducing the of operational carbon as it embodied carbon as well. was designed in 2015 to The total embodied carbon be powered by electricity at practical completion is only. The annual operational equivalent ~ 620 kgCO2e/ carbon emissions will reduce m2. This represents a 38% proportionally to the grid reduction in comparison with decarbonization. The whole the stage the “business as life operational carbon was usual” benchmark for an office estimated around 620kgCO2e/ building (~1,000 kgCO2e/m2). m2 which is less than 50% of the building’s emissions.

Net-zero buildings Where do we stand? 64 02. All electric office building, London, UK

Figure 66: Whole life carbon emissions

62%

38%

In Use B6 – B7

20 e

2 15 tCO 3 10

0 0 10 20 30 40 50 60 YEARS

-5 D life Beyond

Operational Carbon Embodied Carbon

Net-zero buildings Where do we stand? 65 WLCA summary (kgCO2e/m2) Figure 67: WLCA summary (kgCO2e/m2)

620 667 38% Operational 40% Embodied (A1 – A5)

360 22% Embodied (B-C)

Embodied carbon

At practical completion – 26’719 tCO2e

Over the life cycle – 41’155 tCO2e

Operational energy Over the life cycle – 24’820 tCO2e

WLCA – 65’975 tCO2e

Net-zero buildings Where do we stand? 66 03. Complete transformation office building, London, UK

Type Description Office, Complete transformation • 7 storeys office building (retail at • Ground floor and Foundations ground floor) – Thick RC ground slab, piles and Location • Reinforced concrete and pile caps – retained London, UK composite structure (existing and – New piled foundations for new) extension Development stage – Part A – Existing steel frame with – Local reinforcement with mini- Concept design concrete encapsulated columns, piles bracings and Vierendeel frames. • Façade – entirely replaced GIA Precast concrete planks or slab – Semi-curtain walling systems 2 42,776 m on steel deck on steel beams. with ribbon windows New floors created to fill existing – Glazed curtain walling system hall : lightweight composite slabs Rating scheme – Opaque cladding system and new set of columns adjacent Aiming for BREEAM to existing ones – Roof cladding – laminated zinc 2018 Outstanding standing seam system – Part B – Existing precast concrete portal frames and • Little partitions, exposed soffit and Tool shear walls with precast slabs raised floors. OneClick LCA and beams. Mainly retained • Fully serviced with lift (cooling, – openings, infills and minor healing, ventilation, electricity, Project data strengthening water, lighting, sprinkler) Concept design information: • New extension (in plan) and 2 cost plan and drawings. Industry additional storeys – steel framing averages as material specifications. and composite slabs Energy consumption predicted through building energy modelling.

Net-zero buildings Where do we stand? 67 Key embodied CO2e

Material quantities and carbon factors

Structural steel sections and plates • Structural steel profiles, generic, (3,030t) 20% recycled content, I, H, U, L, and T sections • OneClick LCA database

• Carbon factor: 2.51 kgCO2e/kg (This is close to

British steel value for open sections of 2.45 kgCO2e/ kg)

Ready-mix concrete • Ready-mix concrete, RC 32/40 (32/40 MPa), (8,990m3) 25% Cement replacement with blast furnace slag (GGBS) • ICE Database V3

• Carbon factor: 0.12 kgCO2e/kg

Raised access floors • Raised access flooring system, (24,670m2) 60-640 mm Variable height, 30 kg/m2 • Database: EPD Kingspan TLM26 Alpha V

• Carbon factor: 51.8 kgCO2e/m2

Profiledsteel decking for composite floor • Profiled steel decking for composite floor slabs / (315t) decking, 0.9mm sheet thickness, 13.01kg/m2, ComFlor 51+ 0.9mm • Database: EPD TATA Steel

• Carbon factor: 2.72 kgCO2e/kg

Steel reinforcement • Reinforcement steel (rebar), generic, 97% recycled (1,140t) content (typical for UK) • Database: OneClick LCA

• Carbon factor: 0.5 kgCO2e/kg

Services: Heating, cooling, electricity, ventilation, • Average impact per m2 GIA of the different systems lighting distribution systems and lifts. based on past studies • Database: OneClick LCA

• Carbon factor: 10-30 kgCO2e/m2/system total:

approx. 105kgCO2e/m2

Net-zero buildings Where do we stand? 68 03. Complete transformation office building, London, UK

Key operational CO2e

Energy and water Figure 68: Energy consumption by activity consumption Enhanced Building Energy 37% Modelling (similar to Nabers)

Annual energy consumption (Averaged between plot H1 and H2)

118kWhequivalent/m2(GIA)

*This includes a reduction of approximatively 2% of the 21% electricity needs provided by 250 PV panels.

100% electricity 10% 13% Grid carbon factor (SAP 10) • Electricity: Decarbonization progressions based on FES “steady progression” scenario

applied to the current factor of 13%

0.233 kgCO2e/kWh (SAP10) 1 5% % • Natural gas: 0.21 kgCO2e/ kWh Annual water consumption Lighting Tenant Small Power 0.45m3/m2 Landlord Small Power Lifts

Carbon factor: Heating, Cooling and DHW Fans and Pumps • Tap water, clean – Thames IT Servers Water Utilities Ltd:

0.001 kgCO2e/m3

Net-zero buildings Where do we stand? 69 Results

Breakdown of carbon emissions per building element

Figure 69: Embodied carbon at practical Figure 70: Embodied carbon completion (A1-A5) over the life cycle (A-C) 5% 5% 3% 3%

19% 34% 33%

555 kgCO2e/m2 7% 910 kgCO2e/m2

10% 51%

10% 13%

Figure 71: Whole life carbon (A-C)

42% 19%

Substructure

Superstructure

Façade

Internal walls and partitions 6% 1,580 Internal finishes FF&E kgCO2e/m2 Building services

Site emissions 8% Energy and water use

19%

Net-zero buildings Where do we stand? 70 03. Complete transformation office building, London, UK

WBCSD Building System Carbon Framework

Case Study 03 Building Stages

Product Construction Use End of life Beyond Life Whole life carbon emissions A-C kgCO2e/m2 Emissions A1-A3 A4-A5 B1-B5 B6-B7 C D

Substructure – RICS Level 1 Foundations, lowest floor 25 1 0 0.6 27 -3 construction, retaining walls

Structure – RICS Level 2.1 – 2.4 278 4 14 2.1 298 -105 Frame, floors, roofs and stairs

Skin/Façade – RICS Level 2.5 – 2.6 54 0 38 0.1 93 -21 External walls, windows and doors

Space Plan – RICS Level 2.7 – 2.8 11 0 7 0.4 18 -2 Internal walls, partitions and doors

Space Plan – RICS Level 3 40 0 77 0.1 118 -1 Internal finishes Building layers

Stuff – RICS Level 4 4 0 18 0.0 21 -8 Fittings, furnishings and equipment

Services – RICS Level 5 104 1 200 670 1.0 976 -51 Building services

Site emissions (A5) 30 30 Waste, electricity and fuel

Embodied carbon emissions 516 37 354 4 912 -191

Operational carbon emissions 670 670 Energy and water use

Building carbon emissions 516 37 354 670 4 1,582 -191

Net-zero buildings Where do we stand? 71 Project strengths Figure 72: Embodied carbon emissions at practical completion – • Embodied carbon calculations A1-A5 (kgCO2e/m2 GIA) to support decision making 1,000 • Existing substructure reused

• Some existing framing reused -45% • Low predicted energy consumptions next to current 553 standards • 100% electric building • No false ceilings • PVs??

Business Stage 2 Project opportunities as usual baseline The design team have been studying options to further Figure 73: Potential embodied carbon reductions A1-A4 (kgCO2e/m2 GIA) reduce the embodied carbon 553 impact of the future project. -12% 519 489 Amended baseline • Reduce steel weight by adding a line of supports (more 309 efficient system) -21% 275 • Enhancing the GGBS ratios of 245 all concrete

CLT alternative • Using the same steel ratio as amended baseline • Replace composite deck with Baseline Amended CLT CLT slabs (new areas) baseline alternative

Substructure and superstructure Whole building

This project is demonstrating completion, bringing the advanced consideration of upfront embodied carbon whole life carbon from the down to 489kgCO2e/m2, which earliest stage. A whole life will be reassessed at the cycle assessment of the next stage. This is good but stage 2 design approximated does not align with the 40% the total carbon emissions reduction target discussed in over the whole life at the first section of this report. approximatively 1,700 kgCO2e/ However, in comparison m2. The embodied carbon at with the “business as usual” practical completion is 544 benchmark for an office kgCO2e/m2. Further studies building (~1,000 kgCO2e/m2), demonstrated that the building the stage 2 design already could save an extra 12% of exceeds that 40% saving. embodied carbon at practical

Net-zero buildings Where do we stand? 72 03. Complete transformation office building, London, UK

Figure 74: Whole life carbon emissions

58%

42%

In Use B6 – B7

20 e

2 15 tCO 3 10

0 0 10 20 30 40 50 60 YEARS

-5 D life Beyond

Operational Carbon Embodied Carbon

Net-zero buildings Where do we stand? 73 WLCA summary (kgCO2e/m2) Figure 75: WLCA summary (kgCO2e/m2)

543 35% Embodied (A1 – A5)

670 42% Operational

359 23% Embodied (B-C)

Embodied carbon

At practical completion – 23’700 tCO2e

Over the life cycle – 39’000 tCO2e

Operational energy Over the life cycle – 28’700 tCO2e

WLCA – 67’700 tCO2e

Net-zero buildings Where do we stand? 74 04. Refurbishment office building, London, UK

Type Description Office, Refurbishment • 6 storey office building (+1 level of • Main façade systems: aluminum basement) and stone Location • Refurbishment to the existing – Retain 40% of original stone London, UK 6 floors with the partial infill of façade the atrium, infill of the reception, – New unitized stone façade Development stage strengthening of existing vertical panels and Refurbishment completed structure – Aluminum Façade with rock wool • Substructure: New piled raft, insulation and glazing GIA retaining walls and sundry lift pits / • Exposed soffit and services – no 47,264 m2 slab infills, all formed in reinforced false ceiling concrete • Fully serviced with lift (cooling, Rating scheme • Composite steel/concrete heating, ventilation, electricity, LEED V4 Gold superstructure water, lighting) BREEAM 2014 Outstanding – New structure: lightweight steel – Full optimization of services to frame supporting composite reduce operation carbon such as Tool floors innovative heat recovery system OneClick LCA – Existing concrete and steel columns strengthening and Project data existing floor-imposed load Late design stage information – reduced to free up capacity cost plan, drawings and • 1 deep level reinforced concrete specifications. Project Sustainability basement Report. Structural material quantities issued directly by contractor as well as emissions due to site activity. Services embodied carbon calculated from quantities issued by the engineers.

Net-zero buildings Where do we stand? 75 Key embodied CO2e

Material quantities and carbon factors

Ready-mix concrete • Average ready-mix concrete, RC 35/45 (32/40 MPa), (6,750m3) 65% Cement replacement with blast furnace slag (GGBS) • ICE Database V3

• Carbon factor: 0.1 kgCO2e/kg

Structural steel sections and plates • Structural steel profiles, generic, 20% recycled content, (2,390t) I, H, U, L, and T sections • OneClick LCA database

• Carbon factor: 2.51 kgCO2e/kg (This is close to British

steel value for open sections of 2.45 kgCO2e/kg)

Aluminum profile and sheets • Aluminum extruded profile, European Mix, Inc Imports (200t) and European Aluminum profiled sheets • ICE database V3 and IBU EPD Database

• Carbon factor: 6.83 kgCO2e/kg

and 9.32 kgCO2e/kg

Glass • Coated flat glass, 1 mm, max 3,210x6,000 mm, (420t) 2,500 kg/m3 (Guardian Europe) and Toughened Glass • Database: IFT Rosenheim (EPD-GFEV-GB-19.0) and ICE V3.0

• Carbon factor: 1.11 kgCO2e/kg

and 1.67 kgCO2e/kg

Steel reinforcement • Reinforcement steel (rebar), generic, 97% recycled (710t) content (typical for UK) • Database: OneClick LCA

• Carbon factor: 0.5 kgCO2e/kg

Services: Heating, cooling, ventilation, electricity, • Quantities based on data received from project lighting, distribution systems, lifts and others services engineers • Highest contributing material: Air handling unit • Database: OneClick LCA

• Carbon factor: 8.11 kgCO2e/kg

• Total services: 67 kgCO2e/m2

Net-zero buildings Where do we stand? 76 04. Refurbishment office building, London, UK

Key operational CO2e

Energy and water Figure 76: Energy consumption by activity consumption TM54 assessment: In 27% depth operational energy performance evaluation taking in account regulated and unregulated emissions.

Annual energy consumption 25% 149kWhequivalent/m2(GIA)

*This includes a reduction of approximatively 1% of the electricity needs provided by PV panels. 12% 19% 87% electricity / 13% natural gas

Grid carbon factor (SAP 10) • Electricity: Decarbonization progressions based on FES 16% “steady progression” scenario applied to the current factor of

0.233 kgCO2e/kWh (SAP10) • Natural gas: 0.21 kgCO2e/ 1% kWh Lighting Office equipment • Annual water consumption 0.45m3/m2 Heating and DHW Cooling Fans and Pumps Data Center Carbon factor: • Tap water, clean – Thames * Data center accounts for potential server rooms Water Utilities Ltd: 0.001

kgCO2e/m3

Net-zero buildings Where do we stand? 77 Results

Breakdown of carbon emissions per building element

Figure 77: Embodied carbon at practical Figure 78: Embodied carbon completion (A1-A5) over the life cycle (A-C) 6% 7% 4% 4%

22% 38% 25%

315 kgCO2e/m2 535 3% kgCO2e/m2 7% 41% 13% 16%

4% 8% Figure 79: Whole life carbon (A-C)

9% 65% 6% Substructure

Superstructure

Façade

Internal walls and partitions 1,515 Internal finishes FF&E kgCO2e/m2 13% Building services

Site emissions

Energy and water use

Net-zero buildings Where do we stand? 78 04. Refurbishment office building, London, UK

WBCSD Building System Carbon Framework

Case Study 04 Building Stages

Product Construction Use End of life Beyond Life Whole life carbon emissions A-C kgCO2e/m2 Emissions A1-A3 A4-A5 B1-B5 B6-B7 C D

Substructure – RICS Level 1 Foundations, lowest floor 19 1 0.6 21 -3 construction, retaining walls

Structure – RICS Level 2.1 – 2.4 127 2 2 2.6 134 -59 Frame, floors, roofs and stairs

Skin/Façade – RICS Level 2.5 – 2.6 41 0 41 0.1 83 50 External walls, windows and doors

Space Plan – RICS Level 2.7 – 2.8 21 0 21 0.6 43 -16 Internal walls, partitions and doors

Space Plan – RICS Level 3 10 0 12 0.5 23 -2 Internal finishes Building layers

Stuff – RICS Level 4 3 0 3 0.0 6 -6 Fittings, furnishings and equipment

Services – RICS Level 5 67 0 134 983 0.8 1,185 -21 Building services

Site emissions (A5) 20 20 Waste, electricity and fuel

Embodied carbon emissions 289 24 214 5 533 -155

Operational carbon emissions 983 983 Energy and water use

Building carbon emissions 289 24 214 893 5 1,515 -155

Net-zero buildings Where do we stand? 79 Project strengths Figure 80: Carbon emissions at practical completion (kgCO2e/m2 GIA) • Retention of significant areas of the existing raft, and significant alteration works 1,000 minimized

• Retention and upgrade of -69% existing significant parts of the façade • Two thirds of the final floor area from existing structure – reduce floors impact by ap. 50% compare to new built • Cement replacement : High percentage of GGBS – up to 70% • Local procurement of concrete and screed • Adoption of lower concrete grades for low stress 313 elements • Low embodied carbon materials including plasterboard, steel, natural stone, aluminum, and glass • Select of mineral based wool (rather than oil based insulation) to lower the Business As built embodied impact of the as usual building envelope • Engagement with partners / supply chain to establish circular business models for This project is a successful is 313 kgCO2e/m2, this leasing and renting materials example of how building less represents a 68% saving schemes – particularly for and reusing existing structure in comparison with the internal finishes e.g. raised can lead to significant carbon “business as usual” floor, carpet, partitions savings. The total embodied benchmark for an office • Coordination between carbon at practical completion building (~1,000 kgCO2e/m2). disciplines: holistic carbon approach • Early adoption of green building certification schemes to lower embodied carbon impacts across the project life cycle e.g. BREEAM / LEED

Net-zero buildings Where do we stand? 80 04. Refurbishment office building, London, UK

Figure 81: Whole life carbon emissions

35%

65%

In Use B6 – B7

20 e

2 15 tCO 3 10

0 0 10 20 30 40 50 60 YEARS

-5 D life Beyond

Operational Carbon Embodied Carbon

Net-zero buildings Where do we stand? 81 WLCA summary (kgCO2e/m2) Figure 82: WLCA summary (kgCO2e/m2)

313 21% Embodied (A1 – A5)

219 16% 983 Embodied (B-C) 65% Operational

Embodied carbon

At practical completion – 14’813 tCO2e

Over the life cycle – 25’171 tCO2e

Operational energy Over the life cycle – 46’441 tCO2e

WLCA – 71’612 tCO2e

Net-zero buildings Where do we stand? 82 05. Mixed-use building, Copenhagen, DK

Type Description Mixed-use, New build • 6 storey mixed-use building – • Fully serviced with lift – cooling, hosting exhibition spaces, offices, heating, ventilation, electricity, Location an auditorium, restaurant and water, lighting, sprinkler and PV roof Copenhagen, Denmark cafe, a fitness center, residential – connected to the local heating apartments and an automated and cooling system Development stage mechanical car park within the • Very constraint environment – Building in use basement of the building harbour front and building crossed • Composite steel/concrete by a road GIA superstructure 26,366 m2 – Steel frame with storey height trusses acting as bridges, cantilevers or transfer structures Tool OneClick LCA – Hollow core prefabricated concrete slabs Project data – Concrete stability cores Material quantities, transportation • Basement and foundations distances, construction drawings – Reinforced concrete basement and specifications issued by (1 level) and piled foundations contractor and design team. – Secant pile walls and lining wall – Automated mechanical car park system on 3 levels • Façade systems – mixed curtain walling: aluminum, steel, glazing and rockwool insulation panels

Net-zero buildings Where do we stand? 83 Key embodied CO2e

Assumptions specific to project

Transportation scenarios • Concrete, locally manufactured – 13km • Steel reinforcement – 70km • European manufactured products – 300km • Seagoing ship transported steel – 940km • Truck transported steel – 2,090km

Element lifespan • Services – 25 years (suggested by contractor)

Material quantities and carbon factors

Structural steel sections and plates • Structural steel sections and plates, (1,890t) S235-S960 (bauforumstahl) • Data bas: PD structural steel: sections and plates bauforumstahl e.V.

• Carbon factor: 1.13 kgCO2e/kg

Ready-mix concrete • Most common concrete: ready-mix concrete, (21,390m3) normal-strength, generic, C40/50, 30% recycled binders in cement • One Click Database v3 • Carbon factor for most common concrete: 0.12

kgCO2e/kg

Aluminum sheets • Aluminum sheet, 2700 kg/m3 (360t) • Database: OKOBAUDAT 2017

• Carbon factor: 10.62 kgCO2e/kg

Steel reinforcement • Reinforcement steel (rebar), generic, (250t) 90% recycled • Database: OneClick LCA v3

• Carbon factor: 0.67 kgCO2e/kg

Fire-resistant glazing • Fire-resistant glazing, 22 mm, 49 kg/m2 (840t) • EPD CONTRAFLAM

• Carbon factor: 1.95 kgCO2e/kg

Services: Heating, cooling, ventilation, electricity, • Average impact per m2 GIA of the different systems lighting, distribution systems, lifts and others. • Database: OneClick LCA

• Carbon factor: 10-30 kgCO2e/m2/system

• Total services: 120kgCO2e/m2

Net-zero buildings Where do we stand? 84 05. Mixed-use building, Copenhagen, DK

Key operational CO2e

Energy and water Figure 83: Measured energy demand consumption The Building has been 46% operational for 2 years. The data presented was measured during the second year (2019) of the building’s life.

Annual energy consumption 32%

117kWhequivalent/m2(GIA)

• 46% electricity 22% • 32% district heating • 22% district cooling Annual Electricity Demand (kWh)

*In addition, 444 PV panels Annual Heat Demand (kWh) provide 5kWh/m2(GIA) Annual Cooling Demand (kWh) Carbon factors • Electricity: Decarbonization progressions based on FES “steady progression” scenario Figure 84: CO2 intensity of electricity generation –estimated progression applied to the current grid factor – Orsted 2018: 400 0.39 kgCO2e/kWh 350 • District heating – Hofor 2019: 300 0.064 kgCO2e/kWh 250

• District cooling – Hofor 2019: / KWh 2 0.039 kgCO2e/kWh 200

gCO 150 Annual water consumption 100 0.37m3/m2 50 0 Carbon factor: • Tap water, clean (taken from 2020 2025 2030 2035 2040 2045 2050 2055 2060 2065 2070 2075 2080 One Click LCA) – Denmark Adjusted to Danish current carbon factor average: • Global Warming Potential: Simplified general approach

0.3 kgCO2e/m3

Net-zero buildings Where do we stand? 85 Results

Breakdown of carbon emissions per building element

Figure 85: Embodied carbon at practical Figure 86: Embodied carbon completion (A1-A5) over the life cycle (A-C) 2% 10% 7% 14% 23% 3% 30%

880 kgCO2e/m2 1,390 kgCO2e/m2 25% 4% 45%

31%

Figure 87: Whole life carbon (A-C) 4%

33%

20% Substructure

Superstructure

Façade

Internal walls and partitions 2,080 Internal finishes FF&E kgCO2e/m2 Building services

Site emissions

Energy and water use 21%

16%

Net-zero buildings Where do we stand? 86 05. Mixed-use building, Copenhagen, DK

WBCSD Building System Carbon Framework

Case Study 05 Building Stages

Product Construction Use End of life Beyond Life Whole life carbon emissions A-C kgCO2e/m2 Emissions A1-A3 A4-A5 B1-B5 B6-B7 C D

Substructure – RICS Level 1 Foundations, lowest floor 84 1 0 7 91 -20 construction, retaining walls

Structure – RICS Level 2.1 – 2.4 383 12 2 16 413 -50 Frame, floors, roofs and stairs

Skin/Façade – RICS Level 2.5 – 2.6 215 3 215 1 434 -197 External walls, windows and doors

Space Plan – RICS Level 2.7 – 2.8 11 0 11 0 22 -2 Internal walls, partitions and doors

Space Plan – RICS Level 3 24 1 24 8 56 -11 Internal finishes Building layers

Stuff – RICS Level 4 5 0 24 0 29 -11 Fittings, furnishings and equipment

Services – RICS Level 5 120 1 201 692 2 1,009 -46 Building services

Site emissions (A5) 19 19 Waste, electricity and fuel

Embodied carbon emissions 842 36 476 33 1,388 -336

Operational carbon emissions 692 692 Energy and water use

Building carbon emissions 842 36 476 692 33 2,079 -336

PV Offset: -91 kgCO2e/m2

Net-zero buildings Where do we stand? 87 Project strengths Figure 88: Carbon emissions at practical completion (kgCO2e/m2 GIA) • Operational Energy Performance - 50% lower demand than 1,000 industry building average

from Arup Benchmark -12% • On-site renewable energy generation 878 - Solar PV generates just under 10% of the annual electricity demand: 444 PV panels, generating 136,847 kWh per annum • Recycling at decommissioning - 96% materials recyclable at decommissioning • Materials Selection - Prioritisation of products with Danish Climate Labels • Materials Transportation - Short transportation distances for earthworks and in-situ concrete - Use of seagoing ships for steel transportation

Business As built as usual

The total embodied carbon at It is worth noting that the practical completion is 807 project embodied carbon kgCO2e/m2. In comparison impact which is mainly driven with the “business as usual” by the structure is link to the benchmark for an office very constrained environment building (~1,000 kgCO2e/m2), of the site. In addition, the discussed in the first section of building is a new landmark for this report. the city which will probably last for more than 60 years.

Net-zero buildings Where do we stand? 88 05. Mixed-use building, Copenhagen, DK

Figure 89: Whole life carbon emissions

67% 33%

In Use B6 – B7

20 e

2 15 tCO 3 10

0 0 10 20 30 40 50 60 YEARS

-5 D life Beyond

Operational Carbon Embodied Carbon

Net-zero buildings Where do we stand? 89 WLCA summary (kgCO2e/m2) Figure 90: WLCA summary (kgCO2e/m2)

878 692 42% 33% Embodied (A1 – A5) Operational

510 25% Embodied (B-C)

Embodied carbon

At practical completion – 21’270 tCO2e

Over the life cycle – 32’750 tCO2e

Operational energy Over the life cycle – 18’240 tCO2e

WLCA – 50’980 tCO2e

Net-zero buildings Where do we stand? 90 06. Residential timber tower, Amsterdam, NL

Type Description Residential, New build • 21 storey office building (+2 level of • Finishes basement) – 73m high – No false ceiling and Location • Reinforced concrete/timber hybrid no raised floor Amsterdarm, Netherlands superstructure – Top screed (floor heating) – Load bearing internal CLT walls – Floor insulation and additional Development stage – Glue laminated beams screed for fire protection End of construction – Floors CLT/concrete hybrid • Fully serviced with lift (cooling, panels heating, ventilation, electricity, GIA – Cantilevering corners supported water, lighting) 2 14,544 m by steel framing – Stability : concrete core + single Rating scheme CLT wall BREEAM 2014 Outstanding – Reinforced concrete structure for first 2 levels Tool • Substructure: 2 levels reinforced OneClick LCA concrete basement • Foundations: Project data – Precast reinforced concrete piles Design information from tender – Diaphragm retaining wall documents, material quantities from • Main façade system 3D models. Assumptions taken – Prefabricated timber frames with for services embodied carbon Rockwool insulation, aluminum (lower than for office buildings). window frames and triple glazing

Net-zero buildings Where do we stand? 91 Key embodied CO2e

Material quantities and carbon factors

Engineered timber • Cross-laminated timber (CLT), (1,215 m3) 480 kg/m3 (KLH Massivholz), Wooden frameworks from softwood (480kg/m3), and Plywood, generic, 4-50 mm (620kg/m3) • Database: EPD KLH cross-laminated timber panels, INIES (2019) and One Click LCA Database • Carbon factor: 0.4 kgCO2e/kg, 0.17 kgCO2e/kg, and 0.53kgCO2e/kg • Average Biogenic Carbon: 794.7kg/m2 (Biogenic carbon not subtracted from A1-A3 totals) • End of life scenario: Incineration assumed

Ready-mix concrete • Average ready-mix concrete, C32/40 (4,600/5,800 (6,240m3) PSI) with CEM III/A, 40% GGBS content (320 kg/m3) • ICE database v3

• Carbon factor: 0.088 kgCO2e/kg

Structural steel sections and plates • Structural steel profiles, generic, 20% recycled (215t) content, I, H, U, L and T sections • OneClick LCA database

• Carbon factor: 2.51 kgCO2e/kg

Anodized aluminum • Anodized aluminum, Netherlands (27t) • NMD v2.0 database

• Carbon factor: 12.4 kgCO2e/kg

Glass • Flat glass, single to triple glass (6 to 16mm) (4,510m2) • Database: One Click LCA (2018)

• Carbon factor: 12.25 kgCO2e/m2

Steel reinforcement • Reinforcement steel (rebar), generic, (770t) 97% recycled content (typical for UK) • Database: OneClick LCA

• Carbon factor: 0.5 kgCO2e/kg

Services: Heating, cooling, ventilation, electricity, • Assumption taken from industry benchmarks lighting, distribution systems, lifts and others. • Total services: 70kgCO2e/m2

Net-zero buildings Where do we stand? 92 06. Residential timber tower, Amsterdam, NL

Key operational CO2e

Energy and water Figure 91: Energy consumption by activity consumption An assessment was carried 40% out to estimate the regulated energy consumption.

• Annual regulated energy consumption 44kWh/m2 • The unregulated energy consumption was assumed at 20% 20% 30kWh/m2 • Total annual energy consumption

74kWhequivalent/m2(GIA)

65% electricity / 35% 5% 15% district heating

*In addition, 727m2 of PV panels located on the façades and Heating Hot water the roof provide 10kWh/m2 Lighting Others

Grid carbon factors Unregulated energy • Electricity: Decarbonization progressions based on FES “steady progression” scenario Figure 92: CO2 intensity of electricity generation estimated progression applied to the current grid factor of 0.61 kgCO2e/kWh (2019, Netherlands) 400 • District heating: 0.23 kgCO2e/ 350 kWh (taken from OneClick 300 LCA for Netherlands) 250 / KWh • Annual water consumption 2 200 150 estimated at 1.1m3/m2 gCO 100 Carbon factor: 50 • Tap water, clean – Netherlands 0 (One Click LCA):

0.3 kgCO2e/m3 2020 2025 2030 2035 2040 2045 2050 2055 2060 2065 2070 2075 2080

Adjusted to Danish current carbon factor

Simplified general approach

Net-zero buildings Where do we stand? 93 Results

Breakdown of carbon emissions per building element

Figure 93: Embodied carbon at practical Figure 94: Embodied carbon completion (A1-A5) over the life cycle (A-C)

7% 12% 5% 8%

17% 32% 31%

420 kgCO2e/m2 3% 660 4% kgCO2e/m2

12% 44%

5% 16% Figure 95: Whole life carbon (A-C) 4%

14% 54%

Substructure

Superstructure

Façade

7% Internal walls and partitions 1,440 Internal finishes FF&E kgCO2e/m2 2% Building services

Site emissions

Energy and water use

15%

Net-zero buildings Where do we stand? 94 06. Residential timber tower, Amsterdam, NL

WBCSD Building System Carbon Framework

Case Study 06 Building Stages

Product Construction Use End of life Beyond Life Whole life carbon emissions A-C kgCO2e/m2 Emissions A1-A3 A4-A5 B1-B5 B6-B7 C D

Substructure – RICS Level 1 Foundations, lowest floor 51 1 0 0.9 53 -8 construction, retaining walls

Structure – RICS Level 2.1 – 2.4 174 7 9 13.6 205 -96 Frame, floors, roofs and stairs

Skin/Façade – RICS Level 2.5 – 2.6 51 1 51 1.4 104 -37 External walls, windows and doors

Space Plan – RICS Level 2.7 – 2.8 16 0 16 0.5 33 -2 Internal walls, partitions and doors

Space Plan – RICS Level 3 12 1 0 0.3 13 -1 Internal finishes Building layers

Stuff – RICS Level 4 3 0 7 0.1 10 -2 Fittings, furnishings and equipment

Services – RICS Level 5 70 0 140 781 0.8 993 -11 Building services

Site emissions (A5) 30 30 Waste, electricity and fuel

Embodied carbon emissions 377 41 224 17 659 -158

Operational carbon emissions 781 781 Energy and water use

Building carbon emissions 377 41 224 781 17 1,440 -158

Biogenic carbon storage: -146kgCO2e/m2 PV Offset: -61 kgCO2e/m2

Net-zero buildings Where do we stand? 95 Project strengths Figure 96: Carbon emissions at practical completion (kgCO2e/m2 GIA) • Timber primary structural material – lowest carbon structural material and benefit 1,000 from sequestration

• Relatively small spans -58%

• No raised floor -72% • PV panels – on site renewable energy • Efficient energy strategy leads to low regulated energy use • CEM III with 40% of GGBS • Timber façade frame • Coordination between disciplines: holistic carbon approach 418 • Early adoption of green building certification schemes to lower embodied carbon 272 impacts across the project life cycle – BRREAM outstanding

Business As built Including as usual sequestration

This project is a successful embodied carbon at practical example of how using timber as completion is 418 kgCO2e/ primary structural material can m2, this represents a 58% reduce the embodied carbon saving in comparison with the impact. Although a significant business as usual benchmark amount of concrete and steel for an office building (~1,000 were required to achieved the kgCO2e/m2). The benchmark desired geometry and deal with for a middle/high rise would be the ground conditions, the total higher than that.

Net-zero buildings Where do we stand? 96 06. Residential timber tower, Amsterdam, NL

Figure 97: Whole life carbon emissions

46%

54%

In Use B6 – B7

8 e

2 6 tCO 3 10

2 Construction A1 – A5 B4 – FF&E Replacement B4 – Services + FF&E Replacement + Partitions + Façade B4 – Structure Replacement B4 – Services + FF&E Replacement B4 – FF&E Replacement C1 – C4 End of life

0 0 10 20 30 40 50 60 YEARS

-2 D life Beyond

Operational Carbon Embodied Carbon

Net-zero buildings Where do we stand? 97 WLCA summary (kgCO2e/m2) Figure 98: WLCA summary (kgCO2e/m2)

418 29% Embodied (A1 – A5)

781 54% Operational

241 17% Embodied (B-C)

Embodied carbon

At practical completion – 6’079 tCO2e

Over the life cycle – 9’584 tCO2e

Operational energy Over the life cycle – 11’365 tCO2e

WLCA – 20’950 tCO2e

Net-zero buildings Where do we stand? 98 Endnotes

1 United Nations (2021), The Paris 7 Arup (2020), Net-zero carbon 12 The Institution of Structural Agreement. Retrieved from https:// buildings: three steps to take now. Engineers (2020), How to Calculate unfccc.int/process-and-meetings/ Retrieved from https://www.arup. Embodied Carbon. Retrieved from the-paris-agreement/the-paris- com/perspectives/publications/ https://www.istructe.org/IStructE/ agreement. research/section/net-zero-carbon- media/Public/Resources/istructe-

2 buildings-three-steps-to-take-now. how-to-calculate-embodied- United Nations (2020) Climate carbon.pdf. Action Pathway Human 8 International Organization for Settlements. Retrieved from Standardization (2006), ISO 14040: 13 CIBSE (2013), Embodied Carbon https://unfccc.int/sites/default/files/ 2006 Environmental Management and Building Services: CIBSE resource/ExecSumm_HS_0.pdf. - Life cycle Assessment - Research Report 9. Retrieved

3 Principles and Framework. from https://www.cibse.org/ Global ABC/IEA/UNEP (2020), Retrieved from: https://www.iso. knowledge/knowledge-items/ Global Alliance for Buildings and org/standard/37456.html. detail?id=a0q20000008I754AAC. Construction: 2020 Global Report for Buildings and Construction. 9 European Standard EN15978 14 CIBSE (2021), TM65 – Embodied Retrieved from https://globalabc. (2011), Sustainability of carbon in building services: org/sites/default/files/inline- Construction Works – Assessment a calculation methodology. files/2020%20Buildings%20GSR_ of Environmental Performance of Retrieved from https://www.cibse. FULL%20REPORT.pdf. Buildings – Calculation Method. org/knowledge/knowledge-items/ Retrieved from https://shop. detail?id=a0q3Y00000IPZOhQAP. 4 IPCC (2018), Special Report on bsigroup.com/ProductDetail?pid= 15 Global Warming of 1.5ºC. Retrieved 000000000030256638. One Click LCA (2021). Retrieved from https://www.ipcc.ch/sr15/. from https://www.oneclicklca.com/. 10 5 Royal Institution of Chartered 16 Global ABC/IEA/UNEP (2017), Surveyors (RICS) (2017), Whole National GridESO (2021), Future Global Alliance for Buildings and Life Carbon Assessment for the Energy Scenarios. Retrieved from: Construction: 2017 Global Report Built Environment. Retrieved from https://www.nationalgrideso.com/ for Buildings and Construction. https://www.rics.org/globalassets/ future-energy/future-energy- Retrieved from https://www. rics-website/media/news/ scenarios.

worldgbc.org/sites/default/files/ whole-life-carbon-assessment- 17 UNEP%20188_GABC_en%20 for-the--built-environment- UK Gov (2021), Greenhouse Gas %28web%29.pdf. november-2017.pdf. Conversation Reporting Factors. Retrieved from https://www.gov. 6 Our World in Data (2020). Retrieved 11 WBCSD (2020), The Building uk/government/publications/ from: https://ourworldindata.org/ System Carbon Framework. greenhouse-gas-reporting- co2-emissions#year-on-year- Retrieved from https://www.wbcsd. conversion-factors-2020. change-in-global-co2-emissions. org/Programs/Cities-and-Mobility/ Sustainable-Cities/Transforming- the-Built-Environment/ Decarbonization/Resources/ The-Building-System-Carbon- Framework.

Net-zero buildings Where do we stand? 99 18 World Green Building Council 24 Better Buildings Partnership 29 Gold Standard (2021). Retrieved (2021), Whole Life Carbon Vision. (2019), 2019 Real Estate from: https://www.goldstandard.org/.

Retrieved from https://www. Environmental Benchmarks. 30 worldgbc.org/advancing-net-zero/ Retrieved from: https://www. International Carbon Reduction whole-life-carbon-vision. betterbuildingspartnership. and Offset Alliance (2021). Retrieved from: 19 co.uk/sites/default/files/media/ RIBA (2020), 2030 Climate attachment/BBP_REEB%20 https://www.icroa.org/offsetting.

Challenge. Retrieved from: https:// Benchmarks%202019_0.pdf 31 www.architecture.com/-/media/ IEMA (2020): Pathways to Net files/Climate-action/RIBA-2030- 25 Carbon Risk Real Estate Monitor Zero - Using the IEMA GHG Climate-Challenge.pdf. (CRREM) (2021). Retrieved from: Management Hierarchy. Retrieved https://www.crrem.eu/. from: https://www.iema.net/ 20 LETI (2020), Climate Emergency document-download/51806. 26 Design Guide. Retrieved from: BSIA 2040: 2017 (2017), 32 https://b80d7a04-1c28-45e2- The SIA Path to Energy Efficiency. Arup (2021), A Proposed b904-e0715cface93.filesusr.com/ Retrieved from: www.sia.ch/ Methodology for Assigning ugd/ 252d09_3b0f2acf2bb24c korrigenda. Sequestered CO2 from 'Climate 019f5ed9173fc5d9f4.pdf. Friendly' Forest Management 27 to Timber used in Long-Lived 21 World GBC (2019): Net Zero Greater London Authority (2020), Carbon Buildings Commitment, Buildings Products. Retrieved Zero Carbon London. Retrieved Detailed Guidance, v1 January from: https://www.arup.com/ from: https://www.london.gov.uk/ 2019: Appendix B: Guidance perspectives/publications/ what-we-do/environment/climate- for Procurement of Renewables research/section/forestry- change/zero-carbon-london. and Offsets. Retrieved from: embodied-carbon-methodology.

22 https://www.worldgbc.org/sites/ 33 Carbon Leadership Forum default/files/3.%20NZCB%20 IEA's Sustainable Development Initiative (2020), Embodied Carbon Commitment%20Detailed%20 Scenario (SDS) (2020). Retrieved Benchmark Study. Retrieved from: Guidance_Final_V1_Jan%202019. from: https://www.iea.org/reports/ https://carbonleadershipforum.org/ pdf. world-energy-model/sustainable- embodied-carbon-benchmark- development-scenario. study-1/. 28 UKGBC (2021), Renewable Energy

23 Procurement & Carbon Offsetting: One Click LCA (2021), Embodied Guidance for net zero carbon Carbon Benchmarks for buildings. Retrieved from: https:// European Buildings, According www.ukgbc.org/wp-content/ to the EN15978:2011 & Level(s) uploads/2021/03/Renewable- Framework, Retrieved from: Energy-Procurement-Carbon- https://www.oneclicklca.com/eu- Offsetting-Guidance-for-Net-Zero- embodied-carbon-benchmarks/. Carbon-Buildings.pdf.

Net-zero buildings Where do we stand? 100 Abbreviations, acronyms and units of measurement

BAU Business as usual

COP21 Conference of Parties 21

CO2 Carbon dioxide

CO2e Carbon dioxide equivalent

CRREM Carbon Risk Real Estate Monitor

EPD Environmental Product Declaration

EUI Energy use intensity

FES Future energy scenarios

FF&E Fittings, furnishings and equipment

GHG Greenhouse gases

GLA Greater London Authority

ICE Institute of Civil Engineers

IEA International Energy Agency

ISO International Organization for Standardization

Kg Kilogram kWh Kilowatt hour

LCA Life cycle carbon assessment

LETI London Energy Transformation Initiative m2 Meters squared

REEB Real Estate Environmental Benchmark

RIBA Royal Institute of British Architects

RICS Royal Institute of Chartered Surveyors

SIA Swiss Engineers and Architects Association t Tonne

UKGBC UK Green Building Council

WBCSD World Business Council for Sustainable Development

WLCA Whole life carbon assessment

Net-zero buildings Where do we stand? 101 ACKNOWLEDGMENTS ABOUT ARUP ABOUT WBCSD

The Net-zero buildings Where do Arup is a professional consultancy WBCSD is a global, CEO-led we stand? (2021) publication was providing services in management, organization of over 200 leading prepared by Arup in collaboration planning, design and engineering. businesses working together with WBCSD. As a global firm we draw on the to accelerate the transition to The primary contributors of this skills of nearly 15,000 consultants a sustainable world. We help publication are as follows: across the world; our reputation make our member companies in striving to continually develop more successful and sustainable Arup innovative tools and techniques by focusing on the maximum Chris Carroll means that we have the people, positive impact for shareholders, Director, Building Engineering processes and systems to deliver the environment and societies. holistic solutions for clients. Yolande Alves de Souza Our member companies come Engineer, Building Engineering Our work is shaped by our from all business sectors and all mission statement, to Shape a major economies, representing Ellen Salter Better World, and in 2020 we a combined revenue of more Consultant, Environment revised our Global Strategy to than USD $8.5 trillion and and Sustainability put sustainable development 19 million employees. at the heart of everything we do. Our global network of almost WBCSD Arup has committed to achieving 70 national business councils Roland Hunziker net-zero emissions across its gives our members unparalleled Director, Sustainable entire operations by 2030, reach across the globe. Since Buildings & Cities covering everything from the 1995, WBCSD has been uniquely energy used in offices to goods positioned to work with member Luca De Giovanetti and services purchased. To companies along and across Manager, Science-based Targets achieve this the firm has set a value chains to deliver impactful target to reduce its scope 1, business solutions to the most Veronica Contucci 2 and 3 global greenhouse gas challenging sustainability issues. Intern, Built Environment (GHG) emissions by 30% within the next five years from Together, we are the leading voice a 2018 baseline. of business for sustainability: united by our vision of a DISCLAIMER We were founding signatories of world where more than UK Architects Declare Climate 9 billion people are all living This report is released in the name and Biodiversity Emergency well and within the boundaries of WBCSD. Like other WBCSD and UK Engineeers Declare Climate of our planet, by 2050. publications, it is the result of and Biodiversity Emergency. collaborative efforts by members of www.wbcsd.org the secretariat and executives from Arup member companies. It does not 8 Fitzroy Street Follow us on Twitter and LinkedIn mean, however, that every member London company agrees with every word. W1T 4BJ United Kingdom Copyright www.arup.com Copyright © WBCSD, July 2021.

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