UK

Assessment of multiple buildings within a single BREEAM assessment - KBCN1836

Ene01, Ene02 and Wat01, which use area-weighted performance scales, must be assessed using the methodology set out below where multiple buildings are included within the scope of a single BREEAM assessment, including where: • the Similar Buildings approach is applied, in accordance with Section 4 of GN20; or • Separate buildings with a single overarching function are located on the same site, in accordance with Section 6 of GN20 (e.g. a principal building with one or more ancillary or supporting buildings). Ene01 For UK NC projects, energy models (BRUKL files) must be uploaded for each building included within the assessment. For International NC projects, the assessor must enter floor area-weighted average values for the relevant energy performance metrics for both the actual building(s) and the reference building(s), covering all buildings and applicable building uses included in the assessment. Ene02 All buildings included within the assessment must be modelled in accordance with the methodology. The energy performance score must be calculated using floor area-weighted metrics covering all buildings, and compared against a benchmark derived from a floor area weighted average of all building types included within the assessment. Wat01 For Wat01, the assessor must enter details for all water-using components across all buildings included within the assessment. The Wat01 benchmark is determined using a floor area-weighted occupancy by building type, covering all buildings within scope of the BREEAM assessment.

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Life Cycle Assessment for multiple buildings within a single assessment (GN20 – Section 6) - KBCN1835

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.

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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.

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Life Cycle Assessment where similar buildings approach is being followed (GN20 – Section 4) - KBCN1834

Where multiple buildings are included within the scope of a single BREEAM assessment following the Similar Buildings approach, in accordance with Section 4 of GN20, unless identical, each building must be assessed and reported separately within the LCA. 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, the worst-performing building (in kgCO₂e/m²) must be used for benchmarking in line with the Similar Buildings methodology (section 4.2 of GN20). Full evidence must be provided to demonstrate: • That all buildings within scope of the assessment have been included, with individual LCAs completed for each building, and • How results have been separated and, where relevant, how shared elements have been allocated.

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Rationale: In line with Section 4.2 of GN20, BREEAM issues must be assessed for each individual building, with credits awarded based on the worst‑performing building for each assessment issue. The Similar Buildings approach therefore remains an individual‑building assessment methodology and does not constitute a site‑wide assessment, even where multiple buildings are included.

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