Building In A Bushfire Prone Area

Bushfire Attack Level (BAL)

 

Bushfires are a part of life in Australia. Bushfire

A Bushfire Attack Level (BAL) is a determined risk level of the threat to buildings in the event of a bushfire. If your property is located in a designated bushfire prone area, your new home has to comply with the bushfire construction requirements of AS 3959-2009.

Any property within a designated bushfire prone area will need to undertake a BAL assessment to determine which BAL Zone the site location on the property falls into and therefore, which construction requirements of the Australian Standard need to be applied.

 

BAL Explained

 

BAL-LOW (Very Low Risk)

There is insufficient risk to warrant specific bushfire construction requirements. 

BAL-12.5 (Low Risk)

There is a risk of ember attack. 

BAL-19 (Moderate Risk)

Increasing levels of ember attack and burning debris ignited by windborne embers together with increasing heat flux between 12.5 and 19kW/m2 

BAL-29 (High Risk)

Increasing levels of ember attack and burning debris ignited by windborne embers together with increasing heat flux between 19 and 29kW/m2 

BAL-40 (Very High Risk)

Increasing levels of ember attack and burning debris ignited by windborne embers together with increasing heat flux with the increased likelihood of exposure to flames, together with increasing heat flux between 29 and 40 kW/m2 

BAL-FZ (Extreme Risk)

There is an extremely high risk of ember attack and burning debris ignited by windborne embers, and a likelihood of exposure to an extreme level of radiant heat and direct exposure to flames from the fire front. Construction elements are expected to be exposed to a heat flux greater than 40kW/m2

 BAL-Illustration.jpg

 

Higher BAL assessments result in stricter building requirements. Building in areas with high BAL ratings can be complicated and costly, and in extreme cases, impossible to comply with. We strongly recommend getting land assessed for a preliminary BAL rating prior to purchasing. You may choose to make the purchase of the land subject to a BAL rating of 19 or lower.

Ross Squire Homes have built in BAL-40 zones, however, these homes required substantial changes in material, building design and orientation of the house on the land.

On acreage blocks, the BAL rating can change for different building locations. For this reason, it may be worthwhile organising a visit with a BAL assessor on site, as the assessor may identify another part of the land that will attract a lower BAL rating than the spot you may be thinking of building your new home.

 

Do I Need a BAL Report?

 

One of our consultants can help you determine if your property is in a designated bushfire prone area. We can also recommend a BAL assessor in your area who can complete a BAL report for you.