Transition for alterations and extensions in bush fire prone areas

Information status

All documents issued prior to 1 July 2017 were issued by the former Department of Commerce. Documents listed here are the latest versions available, but may be subject to review. For more information on this document, please contact online@dmirs.wa.gov.au.

This publication is for: 
Building surveyorBuilder

The building legislation of Western Australia requires new building work to comply with the Building Code of Australia (BCA). The term building work includes the renovation, alteration, extension, improvement or repair to a building or incidental structure.

To assist in the implementation of the new bush fire reforms in response to the Keelty Report into the Perth Hills 2011 bush fires, a two year transition, until 1 May 2018, of the BCA bush fire construction requirements has been provided to certain renovations, alterations, extensions, improvements or repairs in designated bush fire prone areas.

How does the transition work?

Until 1 May 2018, a renovation, alteration, extension, improvement or repair to certain residential buildings in designated bush fire prone areas does not need to comply with the BCA bush fire construction requirements if it complies with one of the following options:

  • Option 1: the estimated value of the renovation, alteration, extension, improvement or repair is less than $20,000.
  • Option 2: the renovation, alteration, extension, improvement or repair does not increase the risk of ignition from bush fire attack for the existing building.

These options form part of the definition of excluded building work for the purposes of the transition. Examples of excluded building work are provided at the end of this document.

Which residential buildings does the transition apply to?

The transition applies to a renovation, alteration, extension, improvement or repair of the following buildings as classified by the BCA:

  • Class 1, for example dwellings; bed and breakfasts.
  • Class 2, for example apartments.
  • Class 3, for example hotels; accommodation for aged, children or people with disabilities.
  • Class 10a buildings or decks associated with Class 1, 2 or 3 buildings, for example garages, sheds.

The transition does not apply:

  • if the existing building was required to comply with BCA bush fire construction requirements;
  • to the installation of a roof mounted evaporative air conditioner;
  • to a new stand-alone building, for example an outbuilding, garden shed or separate ancillary accommodation; or
  • to the relocation of an existing building.

Do I need to upgrade my existing building?

There is generally no requirement to retrospectively upgrade the parts of your existing building that are not undergoing any change.

Do I need a building permit for my alteration or extension?

Most alterations or extensions require the granting of a building permit from the permit authority (usually the local government in which the building is located) before you can start building works. To check if you need a building permit, please contact your permit authority.

Does my alteration or extension have to comply with other BCA requirements?

Yes. The transition only relates to the bush fire construction requirements of the BCA. All other BCA requirements (for example structural, weatherproofing, ventilation, energy efficiency) still apply to the alteration or extension.

Further information

If you are not sure if your building work needs to comply with the BCA bush fire construction requirements, you should discuss the project with the relevant permit authority.

Examples of excluded building work

Scenario 1

The applicant proposes an alteration to an existing house where the estimated value of the building work is $10,000. Therefore, this alteration is excluded building work, regardless of whether the alteration increases the risk of ignition from bush fire attack for the existing building.

Scenario 2

The applicant proposes an extension to an existing house which is to be constructed from the same materials as the existing building on the side of the existing building that is not exposed to the bush fire prone vegetation. The existing house was not required to comply with the bush fire construction requirements of the BCA at the time of its construction. This extension does not reduce the setback between the existing building and the vegetation or use different materials, so it will not increase the risk of ignition from bush fire attack to the existing building. Therefore, this extension is excluded building work, regardless of the estimated value of the building work.

Scenario 3

The applicant’s existing house is located 40 metres from bush fire prone vegetation. The applicant proposes to construct an extension between the existing house and the vegetation using the same materials as the existing house. The extension of this new part of the building will reduce the setback between the building and vegetation to 20 metres. This increases the risk of ignition from bush fire attack to the existing building. Therefore, if the estimated value of the building work for this extension is over $20,000, this extension is not excluded building work. If the value of the building work for this extension is under $20,000, this extension is excluded building work.

Scenario 4

An applicant proposes to construct a two storey extension that proposes to use combustible cladding over the footprint of an existing building that uses non-combustible cladding. While the construction of the new storey does not reduce setbacks between the existing building and the vegetation, the use of combustible cladding on the extension increases the risk of ignition from bush fire attack to the existing building. Therefore, if the estimated value of the building work for this extension is over $20,000, this extension is not excluded building work. If the value of the building work for this extension is under $20,000, this extension is excluded building work.

Building Commission
Fact sheet
Last updated 24 Oct 2016

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