The RICS whole life carbon assessment (WLCA) standard is set to become the world-leading standard for consistent and accurate carbon measurement in the built environment. This 2nd edition builds upon the success of the existing RICS WLCA standard, having been extended to cover all buildings and infrastructure throughout the built environment life cycle.

Supported by the Department for Transport UK and Zero Waste Scotland, the standard was updated by RICS and an author group of decarbonisation experts following feedback from over 1,300 comments collected through a public consultation. The 2nd edition provides continuity and reliability, while encouraging long-term thinking through reuse, recycling and redevelopment.

“The second edition of whole life carbon assessment for the built environment encapsulates RICS' role as a global leader in the built environment and its duty to steer the industry towards decarbonisation. This second edition is a truly global standard for a global problem. I want to thank our members from every world region, our staff, partner specialists and the Department for Transport and Net Zero Waste Scotland for their hard work and crucial support, which made this a reality.”

Justin Young

RICS Chief Executive

“The UK is a world leader in decarbonising transport. This new standard will help reduce the carbon footprint of not only transport projects, but also from projects across all buildings, as the UK works to grow its economy and reach its net zero goals.”

Jesse Norman MP

Decarbonisation Minister, Department for Transport

“This landmark publication will be a key driver for circularity as it provides a vital standard for assessing carbon over the whole life of a building. This whole life consideration prompts built environment professionals to confront the carbon impacts a building has before, during and after its use.”

Stephen Boyle

Built Environment Manager at Zero Waste Scotland

Importance of WLCA for the global built environment

Using the WLCA standard, assessors can estimate the amount of carbon emitted throughout the life cycle of a constructed asset, from the early stages of development though to the end of life. It gives visibility to embodied carbon, operational carbon, and user carbon – something that is vital to carbon calculations and a unique feature of the RICS standard.

By giving visibility to the carbon cost of different design choices, the standard aims to help manage carbon budgets, reduce lifetime emissions and deliver a net-zero future for the built environment.

Calculating and reporting carbon emissions over the lifecycle of a built asset

Through an assessment methodology based on six key principles:

- Comprehensive

- Data-driven

- Consistent

- Practical

- Aligned

- Integrated

Production

- Raw material extraction

- Manufacturing

- transportation

Construction

- transportation

- assembly

- installation

Operation

- use

- maintenance

- repair

- renewal

End of life

- deconstruction

- waste processing

- disposal


Beyond asset life

potential for:

- reuse

- recycling

- energy recovery

Who is it for and why use it?

Whole life carbon assessment 2nd edition will enable professionals to make prudent decisions to limit the whole life carbon impact of buildings and infrastructure. It facilitates carbon measurement from the production of construction materials to the design, construction and eventual end of life of built assets.

This standard can be used by a range of professionals, from quantity surveyors, cost consultants and building surveyors to designers, engineers and environmental, social and governance consultants, enabling them to meet client demand by measuring and managing carbon emissions in a reliable and consistent manner.

Contractors and developers can use WLCA for a consistent reporting approach that will help them to deliver against both government and client demands for the measurement of embodied carbon, net-zero buildings and infrastructure.

WLCA can also give financial decision-makers such as investors, lenders and others a long-term view of cost and carbon throughout the asset’s life cycle, promoting sustainable and low-carbon building and infrastructure investments.

Alignment with existing carbon standards

WLCA 2nd edition is the world’s only comprehensive standard providing a whole life carbon methodology for projects and assets, allowing professionals to use it alongside their national and regional frameworks, and in conjunction with the International Cost Management Standards (ICMS) 3rd edition, ISO and EN standards.

In the UK, RICS is part of a cross-industry group collaborating to develop the UK Net Zero Carbon Building Standard (NZCBS), which will set out metrics by which net-zero carbon performance is evaluated for buildings. The measurement of carbon emissions to meet the standard will be in accordance with the RICS WLCA standard, and the repository where the data is submitted and stored for benchmarking will be the Built Environment Carbon Database (BECD).

How was it created?

First published in 2017, the WLCA standard mandated a whole life approach to reducing carbon emissions within the built environment. The new edition, authored by world-leading decarbonisation experts and supported by a global expert working group, has been revised extensively to reflect advances in professional practice and updates to legislation and regulatory requirements. It also includes a significantly expanded scope to include all built asset types including infrastructure.

Careful consideration of circa 1,300 comments collected through a public consultation provides assurance that the standard works for the whole industry. You can read more about the development process in the Basis of Conclusion.

 

Author group includes:

Simon Sturgis, architect, team leader for the original 2017 RICS WLCA standard, and team leader of this 2nd edition. Joint author of Greater London Authority WLCA Policy SI2, author of RIBA WLCA guidance, Special Advisor to Environmental Audit Select Committee, ECOS representative for prEN15978, member Part Z team.

Jane Anderson is a leading expert on embodied carbon and environmental product declarations (EPDs) in the construction sector. She is involved in sustainable construction standardisation efforts and is a UK expert to the following international standards committees: CEN TC350 WG3 (product level sustainability standards, e.g. EN 15804, EN 15941), CEN TC350 WG1 (building level sustainability standards, e.g. EN 15978) and ISO TC59 SC17 WG3 (product level EPD standards, e.g. ISO 21930 and EN ISO 22051 (EPD for BIM).  She has recently completed a PhD in which she considered the role of EPDs in embodied carbon reduction.

Paul is the Decarbonisation Lead for Ramboll Buildings globally. As a chartered structural engineer Paul has worked on a large variety of building structures and is an advocate for improved consistency in whole life carbon assessments to allow better decision making. Paul is also one of the authors of the recently published guidance on the Circular Economy and Reuse by the Institution of Structural Engineers and emphasises the importance of considering the end of life of the materials that we use in the built environment.

Louisa Bowles is a Partner and Head of Sustainability at Hawkins\Brown. She has led several multidisciplinary projects and now leads the sustainability team and the in-house whole life carbon tool, H\B:ERT. She is a Mayor’s Design Advocate and actively contributes to a number of industry groups, including LETI, UK NZCBS and the UKGBC. She led the alignment of the WLCA standard with ICMS3 and NRM, including the structuring of the building element categories, reporting and general guidance.

Lee Leston-Jones is a Partner of Structural Engineering at Cundall and has a particular interest and expertise in upfront embodied carbon. He was team leader for updates to modules A1– A5; prior to this, he was responsible for the development of the Construction Industry Council’s Carbon Assessment Tool for the Hong Kong market. He is a member of IStructE’s Structural Future Committee.

Qian has helped developed most of the world's leading whole life carbon frameworks and is advising RIBA, RICS, LETI, CIBSE, ISTRUCTE and the GLA on the development of their whole life carbon standards.  He is also leading a working group updating and aligning the embodied carbon targets of LETI, RIBA and the GLA. He has over ten years’ experience working in sustainable design. He previously worked at a specialist consultancy where he led the Carbon Assessment team, working with property owners and developers (Landsec, Argent, Google etc.).

Athina is an experienced sustainability manager for the built environment with background in civil engineering.  She is currently leading on Sustainability & Carbon for SCS JV, delivering HS2 London Tunnels. Her has significant expertise in decarbonising concrete, steel & construction activities, circular economy, LCA and innovation and is project managing a feasibility study on calcined clay concrete implementation.

Louise is the Global Lead for Sustainable Innovation, leading the development of Introba’s (formally called Elementa Consulting) global lifecycle practice and research, supporting global teams in low carbon assessment and advises architects and clients on design strategies to minimise their environmental impact. She also leads R&D initiatives in whole life carbon studies for building services and their contribution to the performance of the building as a whole. With a degree in both architecture and engineering, she has extensive experience of regenerative design and is the co-author of 'CIBSE TM65 – Embodied carbon of building services: A calculation methodology’.

Clara is the Associate & Carbon Lead at Introba, leading their carbon research and development and is a member of the technical steering group of the UK Net Zero Carbon Buildings Standard on behalf of LETI which she founded in 2017. At Introba, Clara advises developers and local authorities on how to understand and minimise carbon and authors Industry guidance on the subject. She is also a Mayors design advocate for good growth for the GLA and Technical advisor to the Homes England cross cutting committee.

Supporting documents

Whole life carbon assessment - Basis for conclusions

Reporting template – summary

Reporting template – buildings

MEP – supplementary tables

Reporting template – infrastructure

Building element categories

Energy – supplementary tables

FAQs

The methodology in this standard is globally applicable, however numerical assumptions provided are based on UK locations and standard practices due to the availability and accessibility of data. Readers will therefore find that the methodology is more comprehensive and detailed for UK practitioners, however the standard also provides a framework for which WLCA can be effectively undertaken in all other locations and world regions. A full global methodology is not practical due to the variances in and availability of several key components, including specific product data, knowledge of individual countries’ approaches and assumptions to grid decarbonisation and overall end of life assumptions. To help overcome this, the standard provides comprehensive information of what “local” information should be used.

For a whole life carbon assessment to be compliant with this standard, all mandatory requirements must be met whether the assessor is an RICS member or not. A certificate of compliance, as per the WLCA standard, should be produced to provide evidence that the methodology has been applied.

The WLCA standard takes effect on 1 July 2024, nine months after publication. However, RICS will not regulate against the assessments produced or verify the actual results delivered. Instead. we will require that when a WLCA is undertaken by RICS members, it is a mandatory to be done in accordance with our professional standard, unless clear departures from it are identified. Further, RICS members are always required to ensure their professional obligations, in accordance with the RICS Rules of Conduct are met.

The WLCA standard provides the detailed methodology to enable consistent measurement and quantification of whole life carbon emissions, inclusive of all embodied and operational carbon throughout the whole life cycle of the asset, from initial design to end of life.

Included in this methodology is the International Cost Management Standard 3rd Edition (ICMS 3), a high-level reporting classification framework for both cost (capital and life cycle) and carbon of all built environment assets, globally.

The Built Environment Carbon Database (BECD) - currently only available in the UK - will be the repository where the WLCA data is submitted and stored for industry benchmarking and utilisation.

The UK Net Zero Carbon Building Standard (NZCBS), collaboratively developed by a cross-industry group, will set the targets and limits for building assets to be officially recognised as net-zero in line with the required scientific pathways. The measurement of carbon emissions to meet the NZCBS will be in accordance with RICS WLCA.

The International Building Operation Standard (IBOS), launched in 2022, is also an important part of visualising whole life carbon, specifically how carbon is measured while a building is in use, and how this can be reduced, to not only decrease carbon footprint, but to improve the environment of the building for the people who use them.

The 2nd edition of this professional standard is a significant expansion of the first, published in 2017. The most substantial changes are as follows:

  • The 2nd edition aligns with the International Cost Management Standards (ICMS) 3rd Edition and the Built Environment Carbon Database (BECD) to provide a consistent output of cost and carbon reporting and benchmarking, for both new builds and existing assets. It also incorporates other professional guidance around embodied carbon measurement, for example from other professional bodies such as Chartered Institution of Building Services Engineers (CIBSE), Institute of Structural Engineers (IStructE) and the Centre for Window & Cladding Technology (CWCT).
  • It sets a standard approach for assessing whole life carbon across the entire asset life cycle, particularly for benchmarking and early-stage advice, and now extends to both buildings and infrastructure, to enable WLCA to be undertaken across all sectors and asset types. Its better integration with existing software tools will make it easier to be used by SMEs, which make up approximately 80% of RICS members.
  • The 2nd edition incorporates latest industry-agreed definitions for carbon terminology, to enable a clear understanding and approach and standardises the approach to assessing risk in terms of carbon assessment reporting.
  • It addresses uncertainty in WLCA reporting by introducing the mandatory requirement to calculate and report a contingency allowance, which will vary dependent upon the stage at which the WLCA is produced, and the quality of the data being used.
  • From a technical perspective the 2nd edition now includes greater detail of carbon data sources and conversion factors, explains the differences between manufacturer specific data, sector average data and generic data and provides additional guidance on grid and material decarbonisation, carbon sequestration and biogenic carbon. Guidance on retrofit and alignment with the circular economy will enable professionals to work to the most up-to-date standards.

Funding support has come from the UK Department for Transport and from Zero Waste Scotland, a not-for-profit environmental organisation, funded by the Scottish Government and European Regional Development Fund. The funding has gone toward compensating the technical authors and experts who have given their skills, knowledge and expertise to develop this professional standard.

The WLCA standard provides clear guidance on carbon reduction and mitigation. It aligns with national and regional carbon budgets and benchmarks to limit whole life, embodied or operational carbon values.

In the UK, the Built Environment Carbon Database (BECD) will provide a range of carbon benchmarks at both an asset/entity and a material/product specific level. The UK Net Zero Carbon Buildings Standard (NZCBS) will determine the targets and limits for building assets to be officially recognised as net-zero in line with the required scientific pathways.

Yes, these products are currently under development by RICS and will be made available for RICS members as soon as possible.

As part of the development of WLCA 2nd edition, tool providers have been kept informed of the changes, updates and additions made from the 2017 edition. In order for these software tools to be compliant with the updated WLCA standard, they will need to make the required changes once the WLCA Standard takes effect, nine months after publication.