How to find your BAL rating in Australia
A building site's BAL depends on the vegetation near the building, how far away it is, the slope of the ground under it and the regional fire danger index. For a quick indicative answer, BAL Buddy works it out from a map in three steps. A formal BAL assessment is provided by a suitably qualified person.
What goes into a BAL
- The vegetation near the building: what type it is (forest, woodland, scrub, grassland and so on), judged by its structure.
- The distance from the building to it: the closer it is, the higher the BAL.
- The slope of the ground under the vegetation: vegetation on ground falling away from the building is more dangerous.
- The fire danger index for the region, which depends on where the site is.
How a BAL is worked out explains each of these, and how they combine.
A quick indicative answer in three steps
- Find the site. Search for the address or click the map, then confirm the location.
- Draw the building and the vegetation. Trace the building's outline and each patch of vegetation near it, then choose what kind of vegetation each patch is. The vegetation guide describes each class in plain words.
- Read the result. BAL Buddy works out the slope under each patch from elevation data. Press Complete to see the indicative BAL, how it was worked out, and how far the building would need to move for a lower level.
The result comes with a summary you can print, showing the map, the distance and slope for each patch, and what the result relies on. BAL levels explained says what each level means.
What an indicative answer is good for
It's an early answer to help you plan: where the building might go, how the likely level could affect its design and budget, and whether to look further into the site. It isn't a BAL assessment, and the mapping and elevation data it uses can be wrong or out of date, so check what you draw against what's on site.
A formal BAL assessment
A suitably qualified person can provide a BAL assessment. Your building surveyor or council decides which BAL applies to your building, and what they'll accept. Whether your land is in a mapped bushfire prone area is a separate question; your council or the state's own maps can answer it.
BAL Buddy gives an indicative Bushfire Attack Level (BAL) only. It isn't a determination under any Act, and no council or building surveyor has to accept it. For a BAL you can rely on, use an accredited bushfire practitioner.
Need a bushfire practitioner?
FPA Australia keeps a public register of BPAD-accredited practitioners, searchable by state and accreditation level: BPAD practitioner register. If you're not sure who to call, email me and I'll point you in the right direction. I don't take referral fees.
Questions people ask
Can I use an indicative result for a building or planning permit?
No. Use it to understand your site and plan ahead. A permit application needs whatever your building surveyor or council asks for.
Do I need an account?
Not to do the steps. A result needs a run: you can try it free, then pay per run, buy a pack or subscribe (see pricing).
Does it work everywhere in Australia?
It covers the states and mainland territories. It doesn't cover the external territories, and it can't give a BAL where the ground under the vegetation is too steep for Method 1. See the BAL calculator by state.
What if I'm not sure what kind of vegetation it is?
The vegetation guide describes each class by its structure. If you're still unsure, that's worth raising with a qualified person, because the class makes a big difference to the result.
What does BAL mean?
BAL means Bushfire Attack Level. It rates how intense a building site's potential exposure to a bushfire could be, in terms of radiant heat, ember attack and, at the top of the scale, flame contact. There are six levels, from BAL-LOW, the lowest, to BAL-FZ, the Flame Zone. The higher the level, the greater the exposure. BAL levels explained goes through each one.
What is BAL in Australia?
In Australia, the Bushfire Attack Level is the measure the Australian Standard AS 3959 uses to set the construction requirements for buildings in bushfire-prone areas. A site's level, from BAL-LOW to BAL-FZ, reflects its potential exposure to radiant heat, embers and flame, and a higher level means stricter requirements. Each state and territory sets its own rules for when a BAL is needed. BAL levels explained says what each level means.
What does BAL stand for?
BAL stands for Bushfire Attack Level. The term comes from AS 3959, the Australian Standard for building in bushfire-prone areas, and it's written with the level after it, such as BAL-12.5 or BAL-29. The scale runs from BAL-LOW to BAL-FZ, where FZ stands for Flame Zone. The numbers in the middle levels are radiant heat in kilowatts per square metre. See BAL levels explained for all six.
How do I find out my BAL rating in Victoria?
In Victoria, start by checking whether the land is in a designated bushfire prone area, which VicPlan, the state's online planning map, shows. For a BAL you can rely on, a suitably qualified person can provide a BAL assessment. BAL Buddy can give you an indicative BAL first, to help you plan. An indicative result isn't a BAL assessment, and your building surveyor or council decides which BAL applies.