If you’re building a new home or renovating in Perth’s outer suburbs, you’ve probably heard the term “bushfire attack level” thrown around. Maybe your builder mentioned it, or perhaps your insurer asked about your property’s BAL rating.
Understanding your property’s rating means you’ll know exactly what’s required for your windows, doors, screens, and wall vents. This rating is something you can’t ignore, especially if you live in areas like Kalamunda, Darlington, or the City of Swan.
What is a BAL (Bushfire Attack Level) Rating?
A bushfire attack level rating measures the potential exposure your home faces from a bushfire. It considers factors like radiant heat, ember attack, and, in extreme cases, direct flame contact. The rating determines specific construction requirements your property must meet under current building regulations in Western Australia.
The system follows Australian Standard AS 3959:2018, which sets out performance requirements for buildings in bushfire-prone areas. Your local government uses bushfire management overlays to identify which properties need a BAL assessment before they can obtain a building permit.
Bushfire Attack Level Categories
The BAL system divides bushfire risk into six categories, each with increasing levels of protection needed:
| BAL Level | Radiant Heat (kW/m²) | Risk Level | Construction Impact |
| BAL-LOW | <12.5 | Low risk | No special construction required |
| BAL-12.5 | ≤12.5 | Ember attack dominant | Basic ember protection needed |
| BAL-19 | >12.5–19 | Moderate risk | Enhanced ember and radiant heat protection |
| BAL-29 | >19–29 | High risk | Significant construction upgrades required |
| BAL-40 | >29–40 | Very high risk | Extensive protection, possible flame contact |
| BAL-FZ (Flame Zone) | >40 + direct flame | Extreme risk | Maximum protection, direct exposure to flames |
The higher your property’s BAL rating, the more stringent the construction methods and materials you’ll need. This affects everything from your door frames to the mesh in your wall vents.
BAL Rating Assessment for Your Home
You’ll need an accredited BAL assessor to conduct the assessment. In Western Australia, assessors must hold FPAA (Fire Protection Association Australia) Level 1 accreditation. The assessor will visit your property, measure distances to vegetation, analyse slope angles, and consider the asset protection zone around your home. They’ll then provide a report that states your property’s BAL rating and outlines the specific construction requirements you’ll need to meet.
BAL-Rated Windows Requirements and Options
Windows face some of the strictest bushfire requirements because they’re vulnerable to both radiant heat and burning debris. The window glazing, frames, and any openable portions all need to meet your property’s BAL rating.
BAL-12.5 to BAL-29 Properties
- From a minimum of 4 mm toughened glass to additional protection for BAL-29
- Metal window frames (aluminium works well in Perth’s coastal conditions)
- Corrosion-resistant metal mesh with a maximum 2 mm aperture on all openable portions
BAL-40 Properties
- Minimum 6 mm toughened glass
- Non-combustible, metal frames throughout
- Glazing size limited, unless tested to AS 1530.8.1
- External metal mesh screens to prevent ember entry
BAL-FZ (Flame Zone) Properties
You’ll typically need external window shutters or window systems that have passed AS 1530.8.2 testing.
BAL-Rated Doors Requirements & Options
Your door systems need the same attention as your windows. The requirements vary by BAL level, but they all focus on preventing ember entry and withstanding radiant heat.
BAL-12.5 and BAL-19 Properties
- Metal or bushfire-resisting timber door leaf
- Minimum 4 mm toughened glazing if the door includes glass panels
- Weather strips at the base to prevent ember entry
BAL-29 Properties
- All of the above requirements, plus:
- Enhanced screening or tested door systems
- Minimum 5 mm toughened glazing
- Improved sealing and ember protection
BAL-40 and BAL-FZ Properties
- Fully non-combustible and tested metal-framed door sets
- Minimum 6 mm toughened glass for any glazed sections
- Fire-resistant glazing (not standard toughened glass)
- Bushfire shutters are required unless the system is fully certified
BAL Rating and Insurance in Western Australia
Your property’s BAL rating directly affects your home insurance. If you’re planning renovations, upgrading to BAL-compliant windows and doors can be more cost-effective than a complete rebuild. Many homes built between 1980 and 2000 in areas like Ellenbrook, The Vines, and Baldivis can be retrofitted with compliant products.
The state government guides emergency services and local councils. Your council’s planning scheme will show whether your property sits within a bushfire management overlay, and building surveyors can advise on the most practical upgrade path.
Make Your Home BAL-Compliant With Perth Window and Door
Getting your windows, doors, screens and vents right for your property’s BAL rating doesn’t need to be complicated. Perth Window & Door Replacement Company has been helping Perth home-owners meet bushfire requirements for nearly 40 years.
We’ll handle everything from the initial consultation through to professional installation, and we back all our work with a 10-year warranty. Contact us today for a free consultation and quote.
Frequently Asked Questions
The 10/50 rule is a scheme by the NSW Rural Fire Service that lets landholders clear trees within 10 metres of a home and shrubs within 50 metres without approval. Western Australia doesn't have an identical rule. Instead, asset protection zones are set through local bushfire management overlays that vary by council.
BAL-19 addresses radiant heat up to 19 kW/m² (moderate risk) whilst BAL-29 covers up to 29 kW/m² (high risk). BAL-29 requires thicker glass, metal frames, and additional seals compared with BAL-19.
Yes, it does. Insurers factor bushfire exposure into their premium calculations. Homes in higher BAL categories (particularly BAL-40 and BAL-FZ) attract higher premiums unless they show compliant construction. Some insurers request proof of BAL certification before providing quotes.
