Whole-life carbon assessment (WLCA) measures the carbon a building produces across its entire life — materials, construction, operation, maintenance, and demolition. In the UK right now, how that assessment gets done depends on where the project sits and which authority is asking, and new research from the Centre for Construction Best Practice (CCBP) puts numbers on the inconsistency: 70% of the practitioners it interviewed said current policy and regulation has weak or no influence on how WLCA is actually implemented.
That is the finding that matters. WLCA is supposed to turn carbon data into spending decisions — which design gets funded, which bid wins, which materials get specified. Data that cannot be compared from one project to the next cannot do that job, no matter how carefully it is collected.
What the CCBP research found
The Centre for Construction Best Practice opened its research in December 2025, and its initial phase ran 35 interviews and five focus groups with local authorities, contractors, and consultants. Three numbers from that work describe the current state of WLCA in UK public construction:
- 70% of respondents agreed that current policy and regulation had weak or no influence on the implementation of WLCA.
- 59% described the use of WLCA as selective — required on some projects, ignored on others.
- 58% described current policy as fragmented and inconsistent between authorities.
CCBP is now calling on the sector — contractors, consultants, engineers, planners, project managers, clients, and the wider supply chain — to submit evidence on how WLCA is used in public sector construction and infrastructure projects. Its full findings are due in 2027.
Why the inconsistency happens
There is no single national requirement, so individual local authorities have introduced their own guidance — and each local version asks for the assessment in a different way. The result is that the same building, assessed under two authorities' rules, can produce two different carbon numbers.
Conor Neild Crabb, CCBP's head of centre, described a clear common thread in the feedback: the way WLCA is approached varies significantly, and the inconsistencies have knock-on effects for the supply chain and for capital and operational spending. Michèle Young, principal development coordinator at the London Borough of Tower Hamlets, made the mechanism plain: requiring a WLCA lets authorities and industry engage in design discussions around carbon, but without a consistent national framework its potential to support net zero ambitions is limited — and the absence of a national requirement, such as the long-proposed Part Z of the Building Regulations, risks a fragmented approach that reduces the ability to compare outcomes.
Tom Roxburgh, senior sustainability consultant at Pick Everard, added the cost side: differing WLCA standards produce differing results, varying planning requirements and reporting demands have created a bloated assessment process, and one standard may cost more than another without providing better insight for reduction decisions.
What one consistent framework would have to fix
A single WLCA framework is not mainly a paperwork exercise — it has to fix five specific things before carbon data can drive spending and procurement decisions.
1. One methodology. The framework has to fix the boundary of the assessment: which life-cycle stages count, which materials and processes are in scope, and which calculation rules apply. Until two assessors measuring the same building are required to count the same things, their results are not measurements of the same quantity.
2. One trigger. WLCA is currently selective — required by some authorities on some projects. A consistent framework sets a national threshold for when an assessment is required, so the obligation does not change at a borough boundary. This is the role the proposed Part Z is meant to fill for embodied carbon in England.
3. Comparable outputs. Assessments have to report in the same format, against the same reference values, so a client can place two projects' results side by side and have the comparison mean something. Comparability is the property that turns an assessment into evidence.
4. Proportionate cost. When each authority's variant demands a new approach, project teams pay for the assessment process repeatedly — Roxburgh's "bloated" process. One framework means one approach learned once, priced once, and reused, which is what makes it reasonable to ask teams to spend money on carbon reduction rather than on compliance variation.
5. A link into decisions. The end point of the CCBP evidence call is whether consistency could help WLCA "have a greater influence on spending decisions." An assessment that is filed to satisfy a planning condition changes nothing. A framework earns its keep when the number it produces is wired into procurement scoring, design funding, and capital approval — the places where money actually moves.
Why this travels beyond the UK
The UK's WLCA problem is a specific case of a general pattern: carbon rules written at the local level, one jurisdiction at a time, produce data that cannot be compared across the line where the rule changes. Any market where building carbon obligations are set city by city or state by state should expect the same three symptoms the CCBP respondents named — selective use, fragmented policy, and weak influence on real decisions — until the methodology and the reporting format are standardized above the local level.
The sequence matters for practitioners everywhere: consistency first, then comparability, then influence. Carbon data starts driving spending only after the first two are in place.
Frequently asked questions
What is whole-life carbon assessment? Whole-life carbon assessment is the practice of quantifying a built asset's carbon emissions over its full life — extracting and manufacturing materials, transport and construction, operation and maintenance, and end of life — so design and procurement choices can be compared on carbon as well as cost.
What did the CCBP research find? In initial research involving 35 interviews and five focus groups, 70% of respondents agreed current policy and regulation had weak or no influence on how WLCA is implemented, 59% described its use as selective, and 58% described policy as fragmented and inconsistent between authorities. CCBP has opened an evidence call to the whole sector, with full findings due in 2027.
What is Part Z? Part Z is a proposed addition to the Building Regulations in England that would require the assessment — and potentially the limiting — of embodied carbon in new buildings. It is an industry-backed proposal, not current law. In the WLCA debate it stands for the missing piece: a national requirement that applies the same way everywhere.
When will the full CCBP findings be published? CCBP is continuing to gather evidence through its open call, and its full findings are expected in 2027.
Source: Construction Management, "The way we do whole-life carbon assessment is a mess, says Centre for Construction Best Practice" (October 2026), reporting CCBP's initial research and evidence call. Figures quoted are from CCBP's initial findings as reported; the research is ongoing.