A Bushfire Attack Level (BAL) is used to determine the level of potential bush fire attack on a property. Bush fire attack is considered to be potential flame contact, ember attack or radiant heat exposure that may affect a building and damage or destroy it during a bush fire. Building to the correct BAL measure can help a building to potentially survive a bush fire and provide better protection for human life.
It is used to determine the appropriate level of construction required relative to the potential bush fire attack. As part of any application for new works on bush fire prone land bush fire will need to be addressed. A bush fire assessment will need to be undertaken for your property and to satisfy council’s requirements.
Your Builder can guide you through the relevant inspections required in the lead up to lodging your plans for CDC or DA approval.
Below you will find a brief outline of the 6 Bushfire Attack Levels from the NSW Rural Fire Service, as well as a direct link to their website.
The various bush fire attack levels and the associated construction requirements are outlined below.
Minimal attack from radiant heat and flame due to the distance of the site from the vegetation, although some attack by burning debris is possible. There is insufficient threat to warrant specific construction requirements, but residents should still do basic property preparation.
Attack by burning debris is significant with low levels of radiant heat (not greater than 12.5kW/m2). Radiant heat is unlikely to threaten building elements (i.e. unscreened glass). Specific construction requirements for ember protection and accumulation of debris are warranted (Level 1 construction standards).
Attack by burning debris is significant with an increased radiant heat levels (not greater than 19kW/m2) threatening some building elements. Specific construction requirements for protection against embers and radiant heat are warranted (Level 2 construction standards).
Attack by burning debris is significant and radiant heat levels (not greater than 29kW/m2) can threaten building integrity. Specific construction requirements for protection against embers and higher radiant heat are warranted. Some flame contact is possible.
Increased attack from burning debris with significant radiant heat and the potential for flame contact. The extreme radiant heat and potential flame contact could threaten building integrity. Buildings must be designed and constructed in a manner that can withstand the extreme heat and potential flame contact.
Radiant heat levels will exceed 40kW/m2. Radiant heat levels and flame contact are likely to significantly threaten building integrity and result in significant risk to residents who are unlikely to be adequately protected. The flame zone is outside the scope of the BCA and the NSW Rural Fire Service may recommend protection measures where the applicant does not provide an adequate performance solution. Other measures such as drenching systems and radiant heat barriers may also be required.
For a more detailed outline of the construction requirements and an estimate of the cost impact on your build,