Where a BREEAM assessment includes multiple buildings on the same site with a single, over-arching function, in accordance with Section 6 of GN20 (e.g. a principal building with one or more ancillary or supporting buildings), and where these are not classified as ‘similar buildings’, each building must be assessed and reported separately within the LCA.
A single aggregated result for the whole site is not sufficient on its own, even where a single coordinated LCA model is used.
Shared elements (e.g. substructure, external works, or building services serving multiple buildings) may be apportioned between buildings using a reasonable and transparent method (e.g. by gross internal area or other appropriate project-specific metric), in line with recognised industry approaches.
For the purposes of BREEAM benchmarking under Mat 01:
• The results submitted to the platform must represent a single building, not a combined site-wide result.
• Where multiple buildings are included within an assessment, benchmarking (in kgCO₂e/m²) must be based on the principal building. Where no clear principal building exists, the largest building should be used.
Full evidence must be provided to demonstrate:
• That all buildings within scope are included, with individual LCAs completed for each building, and
• How results have been separated and, where relevant, how shared elements have been allocated.
Rationale:
Industry standards such as RICS guidance and the UK Net Zero Carbon Buildings Standard define assessment boundaries at the building (asset) level, while allowing aggregation at project level only where individual building results are also reported.
Requiring building-level results ensures consistency with industry practice, maintains comparability with BREEAM benchmarks, and avoids distortion where multiple buildings are combined into a single result.
Note: This approach applies until further platform functionality is available to support multi-building submissions directly.
