What is a BAL (Bushfire Attack Level), and how does it affect the site of your new home?

If you’re planning to build a home or purchase a new property, you’ll soon come across the term “BAL” (Bushfire Attack Level). It’s important to understand BAL ratings because they can affect your building costs and overall budget - especially if your property has a high risk level. Let’s take a look at BAL classifications and what factors can affect where your property rates.

Is your home bushfire safe? Photo credit:  bertknot

Is your home bushfire safe? Photo credit: bertknot

What is a BAL?

BAL is a nationwide standard that determines the level of risk of a building’s exposure to radiant heat, direct flame contact and ember attack. There are six BAL classifications that form part of the Australian Standards for construction in bushfire-prone areas. A BAL-Low rating is the lowest risk category, whereas a BAL-40 or BAL-FZ means that your property is in an area of significant risk. 

As this risk increases, the types of materials required in the construction of your home will change and costs will increase accordingly. It’s important to note that a high bushfire risk is not exclusive to rural areas.

BAL – Low Lowest risk of potential fire
BAL – 12.5 Low risk – potentially from low risk
BAL – 19 Moderate risk – particularly from embers and burning debris
BAL – 29 High risk – particularly from embers, debris and heat
BAL – 40 Very high risk – Likely to be impacted by embers, debris, heat and potentially flames
BAL – Flame Zone Extreme risk – direct exposure to flames of a potential fire front

Which factors affect my BAL rating?

Your level of bush fire risk is affected by the area in which you live or the block you will be building on, the vegetation, the distance from the vegetation to your home and the slope of the block.


This takes into account access in and out of the property and the number of directions from which a bushfire may approach.

Vegetation type

The vegetation on your site is classified into seven possible types – forests, woodlands, scrub, open scrub, rainforests, grasslands and managed lands. The denser the vegetation, the higher the risk of fire and the higher the potential BAL. Where there is a mixture of vegetation including leaf litter, there may be an increased risk of fire taking hold.

Distance from vegetation

The closer the house site is to vegetation the higher the fire risk. Measurements are taken from the nearest vegetation to the closest proposed external wall or deck.

Slope of the property

The slope of the property affects the spread and speed of a fire. The steeper the slope, the quicker a fire can spread and burn. When assessing the fire risk, it is the slope in the vegetated area rather than between it and the proposed building that is important.

Building your home among the trees brings you closer to nature but at added risk from fire

Building your home among the trees brings you closer to nature but at added risk from fire

How BAL is assessed

You have plenty of options for finding out where your site is likely to rate on the BAL system based on its location and unique features.

  •   Speak to your council. Some councils will have the information on their website (look for Bush Fire Prone Land Map

  • The NSW Rural Fire Service has excellent online tools to help you assess your bushfire risk.  

  •  Obtain an assessment from an accredited Bush Fire Consultant. The Fire Protection Association Australia has information on finding an accredited consultant in your area.  A report from an accredited assessor will be required for construction in a BAL 40 or BAL Flame Zone and may be required if councils require further information during the DA application process. 

How to streamline your BAL assessment and start building faster 


Prominda has a team of expert staff that can guide you quickly through the BAL assessment process. We will take you through an  initial assessment using the online tools available from the NSW government and your local council, individually tailored to your site. From here, our experience dealing with NSW properties means we may suggest site considerations to lower your BAL rating. 

We will also approach your local council early on to determine if an assessment from an accredited consultant is required. If this assessment is required, we will organise it on your behalf for a cost between $500-1500.

Finally, we will submit the BAL rating and or assessment along with your DA. 

Building a bushfire-prepared home with Prominda

Prominda houses are built with steel frames designed to withstand extreme climates. All Prominda houses are designed by default to BAL –19, but can be built to BAL–40 and even BAL – Flame Zone dependent on the needs of your site. A higher BAL rating will require changes to building materials, which may include toughened glass for windows, non-combustible timbers on decks and in the highest levels of BAL, bushfire shutters and weather strips and subfloor enclosures. Prominda will help you make the best decisions to protect your property from fire, allowing you to relax and enjoy the process of building a safe and beautiful new home!

Want to know more about the BAL assessment in NSW?  

Contact Prominda for more information on assessing the BAL rating of your site and building a bushfire-ready modular home.

You can also speak to your local council, or use the following resources put together by state governments:

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