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WAT 03 - Water leak detection and prevention

Information correct as of 5thDecember 2020. Please see kb.breeam.com for the latest compliance information.

Applicability of flow control devices - KBCN00057

The criteria are applicable to the cold water supply only and include cold taps, WCs and urinals. Any solution implemented to achieve compliance with this Issue should effectively mitigate the risk of hot-water scalding in showers, in the event that the cold water supply is shut off.
06/03/18 - Wording amended to make the guidance more outcome-driven and to account for solutions other than not providing flow-control devices on the supply pipework to shower areas.

Fire hydrants and sprinklers - KBCN0680

To meet BREEAM compliance, emergency systems such as fire hydrants and sprinklers need also to be covered by a leak detection system. The leak detection system must cover all mains water supply between and within the building and the ‘site boundary'.

Flow control devices for multiple blocks - KBCN1186

The criteria are set to encourage isolation of the water supply to each WC block when it is not being used. If a single flow control device, for example one programmed time controller, is adequate to switch the water on at predetermined times that suit the usage patterns of more than one WC blocks or facilities, this can be used to demonstrate compliance. Please note that if only one timed controller is used for a large area/number of facilities, the assessor must justify that this is appropriate to the usage patterns within the building and confirm that multiple timers would be redundant (i.e. they would all be set to the same time).  Consideration should be given of any facilities that may be open longer than others, requiring these timers to be programmed differently in different areas. As long as the aim of the credit (‘to reduce the impact of water leaks that may otherwise go undetected’) can be achieved through the specification of an appropriate number of flow control devices, the credit may still be achieved if timers cover more than one WC area/facility to prevent minor water leaks.

Flow control devices on rainwater supply for toilets - KBCN0868

Flow control devices will be required on water supplied from rainwater and serving the toilet facilities. Rainwater tanks are topped up by mains water and leaks could reduce levels of stored water and hence increase the use of mains water. The leak detection requirements apply to all relevant water systems, regardless of the water source.

Flow control on cold water supply - KBCN0417

A shut-off on the cold water supply to the whole WC facility provides a simple and effective way of reducing potential water loss. Taps which contain built in shut-off valves will not prevent any water leaks from the supply to the tap and so do not fulfil this intent. The intent of the flow control criteria is to prevent minor water leaks occurring within the pipework of WC facilities.

Leak detection – extent of responsibility - KBCN0688

For the credit to be awarded, all the pipework in a development that the owner/occupier has responsibility for must meet the leak detection criteria.  In situations where third party organisations place restrictions on the pipework that can be metered, the scope of works (and hence placement of a meter for the use of leak detection) will start immediately after this point.  For instance where the utility company's meter is placed midway between the boundary and the building, the scope of leak detection for BREEAM purposes will be between utility meter and the building, not to the boundary (as stated in the guidance). The scope of the BREEAM criteria is only on pipework that the owner/occupier has control over.

Leak detection – inseparable building and site boundary - KBCN0388

Where there is no distinction between the site boundary and the building; the utility meter being either located on the boundary or within the building, the leak detection criteria apply to the mains water supply within the building only. The BREEAM criteria apply to the pipework that the owner/occupier has responsibility for.  

Leak detection – recycled water use - KBCN0433

The leak detection requirements still apply to all relevant water systems where water recycling systems are specified for WCs and urinals. Recycled water should be considered as a valuable resource as it replaces potable water use and, in many instances, recycling systems will still incorporate a mains-water back up.    

Leak detection – using a BMS - KBCN0439

A BMS can be used for leak detection purposes if it can be demonstrated that its integrated or add-on features meet all the requirements for a leak detection system.

Leak detection between building and utilities meter - KBCN1116

For all pipework which is the responsibility of the building owner or occupier leak detection is required between the building and the utilities water meter. This requirement is applicable regardless of the length of the pipework. Where it can be demonstrated that it is not physically possible for a meter to be installed on the pipework, the requirement for leak detection between the building and the utilities meter can be considered not applicable, and the credit awarded based on the leak detection within the building.

Leak detection system notification - KBCN0245

So long as the compliant system alerts the appropriate person to the leak so they are able to respond immediately, the assessor can judge if the aim of the issue is being met by a reliable, robust and fail-safe means of notification.    

Leak isolation - KBCN0849

Although there are three credits in Wat 03, a maximum of two credits are available, as the credits are not applicable to all buildings. The leak detection system credit (criterion 1) is not applicable to the assessment of residential - single dwellings. The flow control devices credit (criterion 2) is not applicable to residential assessments. The leak isolation credit (criterion 3) is only applicable to residential assessments. The compliance notes CN1, CN2 and CN2.1 confirm this. The criteria will be clarified in the next re-issue of the technical manual.

Shell only assessments – demonstrating compliance - KBCN0771

It is recognised that shell only developments may only include a capped-off water supply, with responsibility for installing the water meter and leak detection system resting with the incoming tenant. In such cases, compliance can be demonstrated where the spatial arrangements, distribution strategy and infrastructure can be shown to facilitate future compliance. This could be demonstrated by evidence such as schematic drawings showing how compliance can be achieved for the assessed development at the fit-out stage. Whilst shell only assessments are intended to consider only aspects which fall within the scope of such developments, in order that the aim of the Issue can ultimately be met, the works should not preclude future compliance.
Information correct as of 5thDecember 2020. Please see kb.breeam.com for the latest compliance information.