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 bushfire prone areas Victoria must comply with the Australian Standard AS 3959-2018 – Construction of buildings in bushfire-prone areas or the NASH Standard – 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.
Find out more about building a home in accordance with the bushfire standards in A guide to building in Victoria after bushfires (PDF, 1590.16 KB).
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.
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)
Description of Predicted bushfire attack
BAL – LOW
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
BAL – FZ
40 kW/m2plus (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
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.
To find out if you live in an area that is subject or likely to be subject to bushfires, create a property report using the Department of Environment, Land, Water and Planning’s VicPlan website.
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 have an existing home located within a BPA, there are many ways to upgrade your home to improve your protection from bushfires. See A guide to retrofit your home for better protection from a bushfire (PDF, 994.81 KB).
Precautions for protecting your home
In addition to the building standards, there are other precautions you can take to help protect your home from bushfires:
- Use building materials appropriate for the conditions and your BAL.
- 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.
- Make sure your property is accessible for emergency vehicles and has a water supply for firefighting. If you have a full rainwater tank near your home, ensure it is accessible.
For more information on bushfire protection and your property, refer to the Department of Environment, Land, Water and Planning's Bushfire protection and my property pages.
You should also familiarise yourself with the Country Fire Authority (CFA) Fire Ready Kit and prepare a bushfire plan. You can also obtain a copy of the kit by phoning the VicEmergency Hotline on 1800 226 226.
VBA bushfire resources
- A guide to retrofit your home for better protection from a bushfire (PDF, 994.81 KB)
- Bushfire Attack Level Assessment Report (PDF, 521.5 KB)
- A guide to building in Victoria after bushfires (PDF, 1590.16 KB)
- A guide to retrofitting certain existing Class 9 buildings for better protection from bushfire ember attack (PDF, 920.06 KB)