WAT 01 - Internal Water Use - BREEAM Knowledge Base

Flow rate for ‘click’ taps - KBCN0543

The flow rate for click taps should be taken as the maximum flow rate, as quoted by the manufacturer, of the lower range before the water break or 'click'. All water consumption is based on 'typical' use patterns and it is assumed that most operations of 'click' taps will be at the lower level.

Flow restrictors - KBCN0976

If a flow restrictor can be demonstrated to effectively reduce the flow of water and it is integral to the fitting or supply pipework (ie not easily removed by the building occupant), this can be accounted for in calculations for this Issue. Such devices must be fit-for-purpose. Proprietary flow restrictors, therefore partly-closed isolation valves, for example, are not an acceptable solution.

Measuring the flow rate of domestic components - KBCN0641

On site testing can be carried out by an appropriate professional to determine the flow rate and capacity of domestic components. This must be overseen by the client’s facilities manager and as-built drawings must be provided to confirm the presence and location of the components and any flow restrictors. Note that the conditions under which the testing is completed must be recorded, e.g. the pressure and the temperature of the water for taps. The assessor could conduct the test provided they are able to carry it out accurately.

15/02/2021: amended to cover all component types.

Shower over bath and a separate shower - KBCN0774

To calculate the water use in this scenario, the flow rates of both showers need to be entered into the water calculator tool as well as the capacity of the bath.

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

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

Domestic Refurbishment / 2012 / 04 - Water /