A five-step way to move carbon hotspots into procurement

Building governance is catching up to infrastructure, not ahead of it

An audience member put this directly to Arcadis: infrastructure already has mandated carbon governance through PAS 2080, so why does building governance lag behind? Arcadis recommends PAS 2080's use across the built environment where possible, and pointed to a cluster of newer voluntary frameworks doing the work a mandate would otherwise do: the UK Net Zero Carbon Buildings Standard, with LETI and the GLA feeding into it, alongside RICS and RIBA guidance for the built environment side specifically.

That gap is also why Part Z, the industry-authored amendment to the Building Regulations, keeps resurfacing in Parliament without yet becoming law. Its authors originally floated mandatory whole life carbon reporting for major projects from 2025/2026, with embodied carbon limits following by 2027/2028, but that timeline has already passed unmet, and a private member's bill inspired by Part Z is still working through the Commons with no government commitment behind it. Until something changes that, a repeatable internal governance loop, not a regulatory trigger, is what's actually moving hotspots into specifications on live projects.

The blocker is rarely the carbon model

Arcadis' own experience, illustrated by a Cadogan Estates refurbishment programme covered in more detail in the "Arcadis turns carbon hotspots into design decisions across two Cadogan buildings" case study, points to four recurring reasons a quantified opportunity never becomes an authorised action:

• Late engagement: options surface after design choices are already locked, often because carbon input arrives at Stage 3 or 4 rather than earlier.
• Cost and programme: carbon gets treated as an addition to the brief rather than integral to whole life value, so it competes with capital cost rather than sitting alongside it.
• Procurement lock-in: specifications and tender requirements don't carry the model's outputs forward, so a hotspot identified at the concept stage never reaches the schedule of works.
• No clear owner: recommendations sit in a report, but nobody is accountable for embedding them into contracts, procurement, or delivery.

"So the question is not, can we model carbon now? We've moved away from that. And it's actually, can we design, specify, buy, and verify the low carbon answer that we've come to calculate?"
— Emma Maltby, Whole Life Carbon and Circularity Lead, Arcadis

Arcadis' five-stages loop that closes the gap

Arcadis has formalised its response into a governance loop with five stages: find, decide, commit, buy, and verify.

Stage 1: Find

Find is the modelling stage: building the baseline in One Click LCA and running hotspot analysis to identify which elements actually drive whole life carbon, rather than assuming.

Stage 2: Decide

Decide uses a RAG-rated risk and opportunities tracker listing everything the model surfaced, rated by how easily each item can be embedded into the design.

Stage 3: Commit

Commit assigns an owner to each item on that tracker. If the team agrees it can be embedded, it's ticked off. If not, the tracker records a specific justification, whether that's cost, supply or programme, so there's evidence for why something was or wasn't taken forward.

Stage 4: Buy

Buy is where the specification work sits: embedding requirements into procurement and early supplier engagement, so specifications and tender documents actually carry the model's output rather than a generic sustainability clause.

Stage 5: Verify

Verify updates the model at each design stage, concept, detailed and post-construction, to check what was specified against what was actually delivered, and feeds that gap into the next project.

Making the low carbon option survive procurement

The most consistent theme, including in the audience questions after the talk, was cost. Arcadis' response reframes it rather than dismissing it: cost pressure isn't going away, but carbon needs to become one of the criteria by which value is defined, evaluated as part of value engineering rather than after it.

Four practical levers came up for making that stick through procurement:

1. Brief it: set carbon outcomes, data requirements and decision points from the outset, not once a design is already fixed.
2. Standardise it: once a specification or detail has been proven on one project, replicate it across a portfolio rather than re-solving the same problem each time.
3. Score it: give carbon meaningful weight in pre-qualification questionnaires, evaluated alongside cost and programme rather than as a tie-breaker.
4. De-risk it: use early supplier engagement and Environmental Product Declaration (EPD) data, so alternatives are comparable and buildable before they reach tender, not proposed cold.

Lower Thames Crossing, cited during the talk as a live example of a commercial system rewarding carbon reduction, set a carbon budget for contractors and offered a financial incentive for every tonne reduced below it. National Highways confirms the scheme's procurement process built in incentives for exceeding contractual decarbonisation targets and that its Development Consent Order contains a legally binding carbon limit, a first for any UK infrastructure project.

What this means for specifiers

1. A hotspot without an owner and a decision record stays a hotspot. Whatever tracker format is used, each item needs both.
2. Benchmarking against a named external standard, not just an internal target, creates a stronger case for a low carbon specification than an unreferenced percentage reduction.
3. Specifications and tender documents are where a model's output either survives or dies. If a carbon opportunity isn't written into the schedule of works, it's not a decision yet.

If you supply materials into this process, manufacturers face the mirror image of this problem, knowing what a specifier's RAG tracker and PQQ scoring actually reward. Read the companion guide, "Unverifiable, not high carbon: Why manufacturers lose in specification.

FAQ

What is a carbon hotspot in a whole life carbon assessment?

A carbon hotspot is a building element or material contributing disproportionately to a project's whole life carbon, usually identified through a life cycle assessment baseline built early in design. One Click LCA runs this kind of hotspot analysis automatically once a baseline model exists, which is how structural steel, façade systems and substructure concrete were flagged as the largest hotspots across the Cadogan Estates projects covered in this piece, well before those elements reached procurement.

Does PAS 2080 apply to buildings as well as infrastructure?

PAS 2080:2023 was expanded in its 2023 revision to cover the whole built environment, including buildings, not infrastructure alone, though adoption in buildings remains voluntary and behind infrastructure, where National Highways has mandated it for its supply chain. One Click LCA's carbon reporting outputs are structured to align with PAS 2080's carbon management requirements, supporting teams preparing to work to the standard on either sector.

What is Part Z and does it apply to my project yet?

Part Z is a proposed, not yet enacted, amendment to the UK Building Regulations that would make whole life carbon assessment and embodied carbon limits mandatory for major projects, with reporting proposed from 2025/2026 and limits from 2027/2028. It isn't law yet, so it doesn't apply directly, but One Click LCA's guide to Part Z sets out how specifiers can prepare a whole life carbon governance process now that would already satisfy it if passed.