Have you used EcoForm's free BAL Estimator, NaTHERS Star Estimator or Commercial Compliance Check?
Try the Calculator Now!Work through the fields below in order — vegetation, distance, and slope are the three inputs AS 3959 Method 1 uses to calculate BAL. Tap or hover the next to any field for a plain-language explanation of what it means and how to measure it.
Please input the closest vegetation type to the development, and/or the most heavily vegetated section. If you have multiple vegetation types close to your proposed building site, it is important to measure and input all vegetation types, as they are each calculated differently and will provide different results. The highest vegetation BAL result applies to all aspects of the development.
Copy your results and send them to us when you request a quote, so we know your indicative BAL results.
Planning-stage estimate only. Compliance with AS 3959-2018 requires a formal assessment by an accredited bushfire practitioner. EcoForm holds FPAA BPAD Level 1–3 accreditation across all classifications.
A full, certified BAL assessment has to be carried out on-site by an accredited bushfire practitioner, no online calculator can replace that. This tool gives you a realistic, fast, free indication so you can budget early, know what questions to ask, and understand whether you're likely looking at a straightforward assessment or a more complex one. Once you have a sense of where you sit, the next step is a site-specific assessment from one of our BPAD-accredited bushfire consultants, backed by full Bushfire Management Plans where subdivisions or larger developments need them.
No. This estimator gives a planning-stage indication using AS 3959 Method 1 defaults. A certified assessment requires an accredited practitioner to inspect the site and issue a BAL certificate your certifier and council will accept.
It's a solid planning-stage guide based on the same distance, vegetation, and slope inputs used in the Australian Standard, but it can't account for site-specific factors an on-site assessor would identify, like unmapped vegetation or multiple slope changes across a block.
Higher ratings mean stricter construction requirements, not that you can't build. Our bushfire team can advise on performance-based engineering solutions that are sometimes available to reduce cost or unlock a design that a standard approach wouldn't allow.