04 - Water - BREEAM Knowledge Base

Converting water consumption into litres per year from new EU energy labels - KBCN1548

The following conversion factors may be used to convert the water consumption on new EU energy labels from litres per cycle (L/cycle) into litres per year (L/year): Dishwasher: multiply water consumption figure on EU energy label by 280 (to go from L/cycle to L/year). Washing machines: multiply water consumption figure on EU energy label by 220 (to go from L/cycle to L/year). This follows equivalent guidance for converting energy consumption (see KBCN1462).

25 Aug 2023 - Correction to 'typo error' for dishwasher conversion factor - previously shown as 208, now corrected to 280.

Shower with multiple shower heads - KBCN0855

To calculate the water use of a shower with more than one shower head, one of the following should be done:

If all of the shower heads can be turned on at once, the flow rates should be added up.
If the shower heads can only be used one at a time, the highest flow rate should be used

22 Feb 2024 - Applied to BIU, BREEAM NC and RFO standards

Sub-metering technologies – Compliance Principle - KBCN1561

Where it can be demonstrated that alternative sub-metering 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 metering standards or technologies are currently recognised as alternatives to pulsed output meters:

M-bus. I.e. systems that comply with the EN 13757 series of standards. Also includes systems complying with the OMS (Open Metering System) standards.

Using water from natural underground sources to offset water consumption - KBCN00094

Water from natural underground sources (for instance aquifer water accessed via boreholes) cannot be used to offset:

NC / RFO: potable water consumption.
IU: utility supplied water consumption.

A significant amount of water used for public consumption is already drawn from aquifers. Private boreholes may be drawing water from the same sources as public utility companies.

27-Mar-2024 - Title and text updated to broaden definition. Scheme applicability updated.

Washer dryers - KBCN0699

Where a washer dryer is specified, the water consumption figure for the wash and dry cycle should be used. The drying cycle of a washer dryer is taken into account because it usually uses water during this drying process (e.g. for cooling during the drying cycle) and in some cases, this water usage can be significant.

18-Nov-2022 - Updated to apply to BREEAM In-Use Version 6

Washing machines and dishwashers – Water consumption data - KBCN1571

The water consumption data used to demonstrate compliance may be based on the lowest full wash cycle (i.e. not a pre-wash cycle, for example).