05 - Water

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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Erratum – Wat 01 – Data requirements for Urinals - KBCN1878

Table 8.2 / Table 62: Data requirements for water-consuming components incorrectly states that the data should be entered as “Flush volume in litres/bowl/hour” for all types of urinals

Water-consuming component	Data requirements
Urinals	Flush volume in litres/bowl/hour

These units should only apply to urinals with a timed flush. Data for urinals with automatic flush should be entered in Flush volume in litres/flush (see below)

Water-consuming component	Data requirements
Urinals with timed flush	Flush volume in litres/bowl/hour
Urinals with automatic flush	Flush volume in litres/flush

The data entry options and units are correct in the BREEAM Platform, and the technical manuals will be updated in the next reissue.

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Leak detection – compliance principle – alternative technologies - KBCN1566

Where it can be demonstrated that alternative leak detection technologies can meet or exceed the capabilities of systems set out in the BREEAM guidance, subject to approval, these can also be considered compliant. It is the role of the Assessor and the project team to provide evidence and justification in a compliance principle query (see KBCN1555). The following alternative solutions are currently recognised:

• Smart leak detection systems that are based on 'self-learning' (machine learning) to determine normal use patterns are an acceptable alternative to systems that require manual pre-sets or manual programming.

06-Jul-2026 - Title updated for consistency. Scheme applicability updated. Principle also applied to refrigerant leak detection.

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