How will a BAL rating affect my house design?

Posted by Nathan Peart on Feb 14, 2019 1:11:35 PM

So you are building a house in a Bushfire Prone area and now you are wondering what that may mean for the future of your home or project. How much will it cost and what changes do you need to make?


BAL construction costs

If you haven't already done so, you may find it helpful to get some background to BAL levels with these articles:

Once your design has been assigned a BAL rating by an accredited bushfire consultant, your construction plans will need to be updated to reflect the correct construction requirements for the level it has been assigned.

There are five BAL levels, each one requires different construction requirements. The levels are BAL 12.5, BAL 19, BAL 29, BAL 40, and BAL FZ. 

Each level will add construction requirements and therefore costs to your building. In the submission by FESA to the Keelty Report they produced this table in regards to cost: (Keep in mind this is nearly 10 years old)

Category of bushfire attack

Base house

Large two storey


light weight


BAL – Low




BAL  – 12.5 




BAL – 19




BAL – 29




BAL – 40








A more recent estimate comes from The Shire of Busselton in Council Agenda dated 11/05/2011 that estimated the costs (above standard constructing standards) of compliance with AS3959-2009.

• BAL – 12.5 – 3-4%
• BAL – 19 – 4-5%
• BAL – 29 – 6-6.5%
• BAL – 40 – 6-10%
• BAL – FZ – 8-10%

So what exactly needs to be done? The list of work required can be quite extensive and will change depending on your BAL level. To try and simplify it a little, we have created this handy reference formatted as a table, which you can download, showing a summary of construction requirements for each BAL level:


Download your free BAL construction requirements table


When Bushfire Smart complete a BAL requirement for your project, we will be able to give further advice on the BAL construction requirements and liaise with you or your building consultants to ensure that the plans reflect the correct construction requirements. 


Need more information about BAL reports, Bushfire Management Plans (BMP), or Energy Efficiency? Drop us a line here or give us a call and we would be happy to help.


Got any questions? Ask here




Topics: BAL, BAL Report, bal level, as3959, as 3595, Bushfire Management Plan, BMP, Construction requirements, BAL Costs