BAL is Bushfire Attack Level; a certified bushfire consultant will need to asses your property and give you a BAL rating. Then its up to your Builder to apply the standard.
The RFS defines the Bushfire attack level as follows;
BAL LOW- Lowest risk from a potential fire.
BAL 12.5- Risk is primarily from potential embers during a fire
BAL 19- Moderate risk, particularly from embers and burning debris.
BAL 29- High risk, particularly from embers, debris and heat.
BAL40- Very high risk. Likely to be impacted by embers, debris, heat and potentially flames.
BAL FZ-Extreme risk. Directly exposed to the flames of a potential fire front.
Fine Cut Building are experts in all aspects of BAL rated builds