AS 3959-2009 Version 1.0
This calculator uses the detailed method for determining the Bushfire Attack Level (BAL) as described in AS 3959-2009 Construction of buildings in bushfire-prone areas (Appendix B – Method 2). Users should be familiar with AS 3959 and should refer to it for the various calculator inputs. This calculator is NOT suitable for use where the effective slope under the classified vegetation (refer Clause 2.2.5 in AS 3959-2009) is more than 20 degrees downslope (refer Figure 2.2 in AS 3959-2009).
Your Name:
Site Address:
Date: 23/01/2021 10:11 AM
Fire Danger Index (FDI)
Classified Vegetation Type
Distance of the site from the classified vegetation type(s)
Effective downslope(s) under the classified vegetation type(s)
*For degree to ratio to percentage conversions refer to Table 2.2 in AS 3959-2009
Site Specific Output
Bushfire Attack Level (BAL) XX
Minimum required distance to achieve: BAL―12.5 W metres
BAL―19 X metres
BAL―29 Y metres
BAL―40 Z metres
This calculator determines the Bushfire Attack Level (BAL) for a given building based on Australian Standard AS 3959-2009 'Construction of buildings in bushfire-prone areas', copies of which can be obtained from SAI Global. Users should be familiar with the Australian Standard in order to use the calculator correctly. The calculator will produce inaccurate results if incorrect input data is entered. It is recommended that users double-check results by calculating the BAL independently in accordance with the Australian Standard before proceeding with any project rather than relying solely on this calculator. To the maximum extent permitted by law, we accept no responsibility whatsoever and exclude all liability (including negligence) for any loss, damage or injury arising from the use of or reliance on this calculator including any third party.

Forest and Wood Products Australia ACN 127 114 185. Exova Warringtonfire Aus Pty Ltd ACN 050 241 524.