If you have had a Bushfire Attack Level (BAL) Assessment conducted and have been given a BAL-40 rating, it probably means that you are very close to classified vegetation i.e. on your own lot or a neighbouring lot. A property that has been marked as Bushfire Attack Level (BAL) of BAL-40 is classified as being subjected to a very high bushfire risk. The bushfire construction requirements are aimed to maximise the safety of all parties involved in case of a bushfire.
Bushfire Attack Level (BAL) rating of BAL-40 is the second highest rating, which means that your property may be exposed to ember attacks and will possibly experience extreme heat flux. A Bushfire Attack Level (BAL) is determined by the amount of heat flux that a structure would be exposed to in the case of a bushfire, this is then measured in kW/m2. BAL-40 is primarily concerned with protection from ember attack and radiant heat greater than 29kW/m² up to and including 40 kW/m². If you are at a risk of Bushfire Attack Level (BAL) rating of BAL-40, chances are that you may not receive developmental approval unless:
- You are proposing a minor development
- It is an unavoidable development
- It is an unattached non habitable structure that does not increase the risk of bushfire to an existing building.
If any of the above scenarios apply to you then your development must comply with the AS3959 bushfire construction requirements for Bushfire Attack Level (BAL) rating of BAL-40. These are summarised as the following:
- Subfloor supports, including support posts, columns, stumps, piers and poles shall be made from a non-combustible material or a system complying with AS 1530.8.1.
- Walls of a structure to achieve compliance with a Bushfire Attack Level (BAL) rating of BAL-40 are to be of non-combustible material, or cladded with non-combustible materials or a combination of the materials specified by the AS3959.
- Roof covering shall be made of non-combustible or materials specified by the AS3959 and the underside of roofs are to be sealed to avoid any gaps and threat of ignition through ember attack.
- All unclosed structures such as Verandas, Decks, Steps, Ramps and Landings must be made from a non-combustible material or a system which complies with the AS 1530.8.1.
- All doors and windows must be fully covered by bushfire shutters or screens.
- Door and window frames and all assemblies are to be metal.
- All glazing shall be toughened Grade A safety glass which a minimum thickness of 6 mm.
- Ember guards and mesh screens are to protect all openings vents, weep holes etc.
- Joint openings in all joinery to be kept at a minimum size as specified by the AS3959.
- All water and gas supply pipelines to be made from metal.
If you have received a Bushfire Attack Level (BAL) rating of BAL-40, the first step would be looking into the reduction of fuel load on your own site. However, if you have a bush site or in the hills with a lot of vegetation on site and are not able to manage the vegetation unless you receive an approval, you should consider contacting us your local BPAD accredited level 2 Bushfire Attack Level (BAL) Assessor and inquire about a Bushfire Management Plan (BMP). This will give a future scenario on how you will manage the vegetation on your own lot once you are ready to build. If the vegetation is outside your property, you may have a more complex case, it would be best to discuss in length with our level 2 Bushfire Attack Level (BAL) Assessor.