BUSHFIRE ATTACK LEVELS – BAL RATINGS
Version Date: 2025-12-29
Delta Panels Pty Ltd - ABN: 11 147 861 292
E: info@deltapanels.com   
W: www.deltapanels.com    
Head Office: 731 Boundary Road, Richlands, Qld 4077    P: +61 7 3271 2170    
Sydney Depot: 11 The Old Northern Road, Narellan, NSW 2567   P: +61 2 4611 7712      
THE BAL LEVELS EXPLAINED
There are six levels of Bushfire Attack Levels (BAL) as outlined in AS 3959:2018 Construction of buildings in bushfire-prone 
areas. They are:
(a)    BAL-LOW
There is insufficient risk to warrant any specific construction requirements but there is still some risk
(b)    BAL-12.5
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
(c)    BAL-19
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
(d)    BAL-29
There is an increased level of ember attack and burning debris ignited by wind borne 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
(e)    BAL-40
There is a much increased risk of ember attack and burning debris ignited by wind borne embers, a likelihood of 
exposure to a high level of radiant heat and some like 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 40 kW/m2
(f)     BAL-FZ
There is an extremely high risk of ember attack and burning debris ignited by wind borne embers, a likelihood of 
exposure to a high level of radiant heat and some like 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 40 kW/m2

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