Determining the Bushfire Attack Level (BAL)
In accordance with Australian Standard AS 3959-2009; or
Building in a Wildfire Management Overlay Applicant’s workbook 2010

Contact us for a quote to do your BAL report or your WMO report

Bushfire Attack Level (BAL) Ratings and indicative Costs

As a rough guide, the industry generally is reporting the following addition building cost for every increase in
BAL rating level (based on a Medium sized house). Some companies seem to be charging approx $1000 x BAL number
ie BAL-12.5 can cost an additional $12,500 – we think this is unwarranted:

(1) BAL-Low         no special construction requirements

(2) BAL-12.5     +$3,000 to $5,000
The risk is considered to be LOW.
There is a risk of Ember Attack.
The construction elements are expected to be exposed to a heat flux not greater than 12.5 kW/m2

(3) BAL-19         +$5,000 to $9,000
The risk is considered to be MODERATE.
There is a risk of Ember Attack and burning debris ignited by wind borne embers and a likelihood of exposure to radiant heat.
The construction elements are expected to be exposed to a heat flux not greater than 19 kW/m2

(4) BAL-29         +$18,000
The risk is considered to be HIGH.
There is an increased risk of Ember Attack and burning debris ignited by windborne embers and a likelihood of exposure to an increased level of radiant heat.
The construction elements are expected to be exposed to a heat flux not greater than 29 kW/m2

(5) BAL-40         +$30,000
The risk is considered to be VERY HIGH.
There is a much increased risk of Ember Attack and burning debris ignited by windborne embers,
a likelihood of exposure to a high level of radiant heat and some likelihood of direct exposure to flames from the fire front.
The construction elements are expected to be exposed to a heat flux not greater than 40kW/m2

(6) BAL-FZ (Flame Zone)     +>$50,000
The Risk is considered to be EXTREME
There is an extremely high risk of ember attack and burning debris ignited by windborne embers, and a likelihood
of an extreme level of radiant heat and direct exposure to flames from the fire front.
The construction elements are expected to be exposed to a heat flux greater than 40kW/m2


As yet limited FZ elements have been developed and approved, additional costs could possible reduce to say $40k
depending on the future solutions developed. Only a limited number of FZ roofing solutions have been accepted by the Building Commission.
Flame Zone window solutions are slowly becoming available. In particular a lot of Kit Home suppliers and other
Builders cannot comply with BAL-FZ and BAL-40 and possibly BAL-29.

With the additional cost (and current uncertainty with material approvals) associated with the higher BAL levels
it may be prudent to spend additional time with various scenarios to see if a different BAL can be justified.


Available 7 days a week – ring us on 0417 885 747

We would welcome the opportunity of expanding on any of the points mentioned above.

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BAL ASSESSMENTS
Mobile: 0417 885 747
email: John@BAL.net.au

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