Bushfire protection

Victoria is one of the areas most at risk of bushfires in the world. Domestic buildings and some residential buildings (such as boarding houses) constructed in Victoria must comply with the Australian Standard AS 3959-2018 – Construction of buildings in bushfire-prone areas or the NASH Standard 2014 – Steel Framed Construction in Bushfire Areas. This applies to all new domestic buildings, alterations and additions in Victoria, including associated garages and sheds.

While the standards reduce the risk of ignition of homes in Victoria's bushfire-prone areas, it is important to note that it does not guarantee a building will survive the unpredictable and often devastating nature of a bushfire.

For information on bushfire bunkers, see Private bushfire shelters.

Bushfire Attack Level (BAL)

The residential building standard for bushfire protection aims to improve the ability of a building to withstand a bushfire attack. This provides greater protection for the occupants who may be sheltering inside while the fire front passes.

The following chart outlines how the baseline data, which is defined as a Bushfire Attack Level (BAL), determines the type of construction required for you to obtain a building permit.

The BAL takes into consideration a number of factors, including the Fire Danger Index, the slope of the land, types of surrounding vegetation and its proximity to any building.

Bushfire attack level

Radiant heat exposure (AS 3959)
and levels of exposure

Description of Predicted bushfire attack and levels of exposure


The risk is very low and radiant heat on the building is not significant enough to warrant specific construction requirements; however ember attack may still occur.
If you are in a designated BPA and your bushfire attack level is BAL - LOW, you must still construct to a minimum BAL 12.5.

BAL - 12.5

0 to 12.5 kW/m2 Primarily risk of ember attack; risk of radiant heat is considered low.

BAL - 19

12.5 to 19 kW/m2 Risk is considered moderate with increasing levels of ember attack and burning debris ignited by wind borne embers; increasing likelihood of exposure to radiant heat.

BAL - 29

19 to 29 kW/m2 Risk is considered to be high with increasing levels of ember attack and burning debris ignited by wind borne embers; increasing likelihood of exposure to radiant heat.

BAL - 40

29 to 40 kW/m2 Risk is considered to be very high. Increasing levels of ember attack and burning debris ignited by wind borne embers; increasing likelihood of exposure to radiant heat and some direct exposure to flames possible.


40 kW/m2 + (flame contact) Risk is considered to be extreme. Direct exposure to flames from fire front is likely in addition to high levels of radiant heat exposure and ember attack.

Bushfire prone areas and bushfire management overlays

Victoria's bushfire prone areas (BPAs) have been determined using up-to-date scientific information and data, taking into account factors such as weather, topography and vegetation.

If you are going to be building a new home within a BPA, then you'll need a BAL assessment. All new homes constructed in a BPA must be built to a minimum BAL 12.5 to help withstand ember attack. This includes sealing roofs, sealing around doors and windows and screening windows. Higher construction levels may be required as determined by the site BAL assessment.

If you are in an area of extreme bushfire hazard, it is likely that your property will be in a Bushfire Management Overlay (BMO) and your council's planning scheme will apply to its development and use. You will need to apply for a planning permit in addition to applying for a building permit.

For more information about building under a BMO, contact your local council or visit the Department of Environment, Land, Water and Planning's Bushfire Management Overlay page.

Precautions for protecting your home

There are many ways to upgrade your home to improve protection from bushfires. We recommend the following precautions to help protect your home:

  • Seal gaps with joining strips, silicon weather strips, draught excluders on side-hung doors.
  • Seal vents and weep holes in external walls with corrosion resistant steel, bronze or aluminium mesh.
  • Seal around roofing and roof penetrations.
  • If an evaporative cooler is installed, protect it with a mesh screen.
  • Clear leaves from gutters and considering installing an appropriate leaf-guard product.
  • Check that your gutters are in good condition and will hold water if you block the downpipes.
  • Enclose the subfloor of your home with a non-combustible material.
  • Install shutters or metal flyscreens to doors and windows.
  • Remove any overhanging tree branches, take out shrubs over one metre high next to or below windows, keep grass short and clean up other debris near your home that could easily catch fire.

It is also important to make sure your property is accessible for emergency vehicles and has a water supply for firefighting. If you have a rainwater tank near your home, ensure it is accessible.

More information

VBA bushfire resources