📘 Understanding AS 3959: A Plain English Guide for Homeowners

Building in a bushfire-prone area means complying with AS 3959—but what does that actually mean for your home?

Here’s a straightforward guide to help you understand what AS 3959 is, why it matters, and how it affects your building design.

What Is AS 3959?
AS 3959 – Construction of Buildings in Bushfire-Prone Areas is the Australian Standard that outlines how buildings must be designed and constructed to reduce bushfire risk. It provides clear construction requirements based on your BAL rating.

Not sure what a BAL is or what your BAL rating actually means? Check out our other resources for a range of information.

Why Does It Matter?
Compliance with AS 3959 isn’t optional. Your BAL rating determines which section of the standard applies to your build. Each level has different requirements for things like materials, construction methods, and ember protection.

What Changes With Each BAL Level?

• BAL LOW – No additional bushfire construction requirements.

• BAL 12.5 – Basic ember protection for windows, doors, and vents.

• BAL 19 – Enhanced protection, including tougher window glazing.

• BAL 29 – Upgraded materials, seals, and ember screens required.

• BAL 40 – Non-combustible construction and detailed sealing measures.

• BAL FZ (Flame Zone) – Highest risk level. Requires specialised construction and may involve a performance-based design solution.

Examples of What AS 3959 Covers:

• Ember protection screens over windows and vents

• Metal flyscreens and door frames

• Non-combustible decking materials

• Sealing of gaps in external walls

• Roofing systems that prevent ember entry

What You Need to Do as a Homeowner:

• Ensure your design meets the right BAL standard

• Choose a builder experienced with AS 3959 construction

• Keep documentation consistent with your BAL rating

• Factor BAL-related costs into your budget early

Need a Bushfire Assessment? Contact us today for a free quote.