Backflow prevention devices are used to prevent the contamination of the public water supply and protect anyone using the building and its facilities. We explain how to avoid backflow when you connect.

A building consent is required for most backflow preventers, but if you have already applied for a building consent for other work you can include your backflow device in this application.

The Council may also consider an application for an exemption from building consent where the work is being undertaken by people with a proven record of compliance. We recommend engaging a professional experienced in installation and the building consent application process.

A backflow prevention device is a specified system, so needs to be included on a compliance schedule and on the building warrant of fitness. Please refer to our webpage for more information.

To apply for a building consent for backflow preventers, please include in your application: 

Application for a building consent (Form B-002 - Doc [DOCX, 425 KB] or PDF [PDF, 818 KB])

Backflow prevention device check sheet [PDF, 96 KB] (Form B-052)

About backflow devices

  • There are various devices used to protect against backflow, e.g. dual check devices, testable double check valves, air gaps and testable reduced pressure zone devices which are installed at the water connection.
  • The type of device used would depend on the risk and consequences of backflow.
  • These devices are added to the building's compliance schedule as they are part of the building's specified systems.

Refer to specific information about backflow prevention and backflow devices.


Refer to the Building Consents Fee Schedule for more information.

Please note: The fixed fees and minimum application fees do not always cover all of the consent related costs of an application.