Building or Renovating in a BAL Rated Area: What You Need to Know
If you’re planning to build or renovate in a bushfire-prone area, understanding BAL ratings (Bushfire Attack Level) is essential. These ratings form part of the Australian Standard AS 3959:2018 – Construction of Buildings in Bushfire-Prone Areas, and are designed to improve the resilience of homes during a bushfire event.
At Glenstone, we’ve worked on numerous projects in the Blue Mountains and surrounding regions where BAL compliance is not just a box to tick—it’s a vital part of responsible, long-lasting construction.
Project: Spencer Street, Leura - New build in a BAL Flame Zone
What Is a BAL Rating?
A BAL (Bushfire Attack Level) measures the risk of a building being exposed to ember attack, radiant heat, and direct flame contact during a bushfire.
There are six BAL levels, ranging from minimal risk to extreme exposure:
BAL–LOW – Very low risk, no specific construction requirements.
BAL–12.5 – Low risk, primarily from ember attack.
BAL–19 – Moderate risk, from embers and some heat flux.
BAL–29 – High risk, increasing heat and ember exposure.
BAL–40 – Very high risk, with greater radiant heat and possible flame contact.
BAL–FZ (Flame Zone) – Extreme risk, direct exposure to flames possible.
The BAL rating for your site is determined by a bushfire assessment, which considers vegetation type, distance from vegetation, slope, and local fire conditions.
What Does It Mean for Your Build or Renovation?
Your home’s BAL rating will directly affect design choices, material selection, and construction methods. This can include:
Non-combustible materials for external walls, roofs, and decks.
Bushfire-rated windows and doors with metal screens or toughened glass.
Enclosed eaves and vents to prevent ember entry.
Metal mesh screens on openings for ventilation.
Gutters with ember guards to prevent debris build-up.
These measures not only help your home meet compliance standards but also significantly improve its durability and safety.
Project: Golden Vale, Megalong Valley - New Build in a BAL rated zone
Building Smart in a BAL Zone
Working with a builder experienced in bushfire-prone areas can make all the difference. At Glenstone, our team understands the complexities of AS 3959 and works closely with certifiers, engineers, and local authorities to ensure full compliance—without compromising on design or functionality.
We approach each project with a focus on balancing safety and aesthetics, creating homes that feel warm, comfortable, and well-integrated into their natural surroundings.
Considering a Renovation?
If you’re renovating an existing home in a BAL-rated area, your project may trigger new compliance requirements—especially if you’re extending or altering the external envelope. It’s important to review your site’s updated BAL assessment and consult your builder early in the design phase.
Building or renovating in a bushfire-prone area doesn’t have to mean sacrificing style or liveability. With the right planning, materials, and expertise, your home can be both beautiful and bushfire-resilient.
At Glenstone, we’re proud to help homeowners create safe, compliant, and enduring homes that stand the test of time—and the elements.
