Clarification of ‘Embodied carbon benchmark comparison’ - KBCN1819
The
embodied carbon benchmark comparison must always be based on the
latest appropriate LCA stage that corresponds to the BREEAM assessment stage being pursued.
The purpose of the benchmark comparison is to assess
outcome-based embodied carbon performance, using data that is representative of the building at the relevant assessment stage.
Assessment stage requirements
Interim (Design Stage) BREEAM assessments
- Where an interim / design stage assessment is being submitted:
- The benchmark comparison may be based on a Technical Design LCA, where this represents the latest LCA available at that stage.
- Benchmark results at this stage are indicative and intended to support design decision-making.
Final Post-Construction Stage (PCS) BREEAM assessments
- Where a final post-construction stage (PCS) assessment is being submitted:
- Benchmark comparison credits can only be awarded where a Post-Construction Stage (PCS) LCA has been completed.
- A technical design LCA alone is not sufficient to support benchmark comparison credits at PCS.
- This is because the PCS LCA is the only assessment that reflects the materials and products actually installed in the completed building, and therefore the only suitable basis for outcome-based benchmarking.
If a PCS LCA is
not undertaken, benchmark comparison credits
cannot be awarded at final assessment, regardless of whether a technical design LCA was previously completed.
This aligns with wider industry frameworks (e.g. RICS WLCA v2 and the UK Net Zero Carbon Buildings Standard), which anchor performance claims to as-built outcomes.
GN51 Guidance on LCA and embodied carbon calculations for Mat 01 in BREEAM V7 - KBCN1684
Latest version: v1.0, July 2026
Guidance Note 51 (GN51) provides supporting information for the new Mat 01 criteria in BREEAM V7. Its development is driven by the introduction of new credit allocation criteria for Mat 01. While the core principles of measuring and reporting a building's environmental performance through life cycle assessment (LCA) and benchmarking were introduced in BREEAM UK New Construction 2018, significant revisions have been made to align the criteria across BREEAM schemes and with existing LCA frameworks and methodologies. This guidance note explains the primary methodology for Mat 01, including minimum requirements and the scope of the LCA.
Download Guidance Note 51
View all Guidance Notes on BREEAM Projects (licensed assessors only)
15-Jul-2026 - Updated version released (v1.0)
Information correct as of 20