Every framework on a UK project asks for a whole life carbon number, and almost none of them ask for the same one. They sit on different editions of the RICS methodology, count different environmental indicators, draw the element boundary in different places, and set the target on different module ranges. The study period is the rare thing they agree on. A benchmark lifted from one and applied to another is not a comparison.

This tool sets fifteen frameworks side by side. The opening view takes the five most often argued over on live projects — BREEAM NC v7, LETI/RIBA, UK NZCBS, GLA and other local planning authorities — across the six dimensions that decide whether two numbers can be compared at all. Switch on divergence marking to see where each one breaks from the pack. Behind that sit the fuller scope comparison, a module-by-module coverage table, cards for briefing notes, and the scope traps I keep running into.

Open the matrix on its own page ↗

Sources and caveats

The at-a-glance comparison follows a Buro Happold summary of BREEAM NC v7, LETI/RIBA (2021), UK NZCBS, GLA (2022) and other local planning authorities. Module definitions, element categories and reference study periods are from Whole life carbon assessment for the built environment, RICS professional standard, 2nd edition, which sets the reference study period at 60 years for domestic and non-domestic buildings, 120 years for infrastructure, and 20 plus 60 years for standalone fit-out. The remaining framework entries carry over from my own working notes.

One correction to the source summary, which gave BREEAM a 50-year study period. It is 60. BREEAM's own knowledge base asks for total building environmental impact results at year 0 and at a 60-year study period, and One Click LCA's Mat 01 guidance says the same — so all four named frameworks agree with the RICS 60-year reference study period. Corrected here on 25 August 2026.

Where a value is unverified or genuinely varies, it says so rather than guessing. Divergence marking is my editorial judgement about which cell breaks from the pack on each row, not a quality ranking; two frameworks can differ for good reasons. Compare targets only after aligning module scope, element scope, building type, study period, sequestration treatment and floor area basis.