Understanding Bushfire Attack Level (BAL) Ratings When Building a New Home

15th April 2024

Pre-Construction

This article explains what Bushfire Attack Level (BAL) means for new home builds in Australia, including the six BAL ratings, potential costs, and how it affects construction requirements. It offers practical advice for home buyers to identify their BAL zone and understand what’s involved.

Understanding Bushfire Attack Level (BAL) Ratings When Building a New Home

When building a new home in Australia, one term that might pop up in your builder’s quote is Bushfire Attack Level (BAL). It’s not just another bit of jargon – BAL is an important part of your home’s compliance and safety, particularly if you’re in a bushfire-prone area.

In this episode of the Home Building Hub Podcast, Colin Bischof and Darren Brennan take a practical look at what BAL means, how it affects your build, and what costs might be involved.

You can listen to or watch the full episode here.

What is Bushfire Attack Level (BAL)?

BAL measures the potential risk your home faces from bushfire elements such as ember attack, radiant heat, and direct flame. If your property falls within a designated BAL zone, it means your home must be built to comply with specific bushfire safety measures.

In short – the higher the BAL rating, the higher the bushfire risk, and the more protections are required in your home design.

The Six BAL Ratings (AS3959)

Australia uses six BAL ratings under standard AS3959 to classify risk levels:

• BAL Low – Minimal risk. No extra construction requirements needed.

• BAL 12.5 – The most common level in new greenfield estates. Low risk, but still requires some protection.

• BAL 19 – Moderate risk, typically near reserves or larger trees.

• BAL 29 – High risk. More intensive construction requirements apply.

• BAL 40 – Very high risk, often near dense bushland or national parks.

• BAL FZ (Flame Zone) – Extreme risk. Requires specialist construction such as metal frames and sealed roofs.

Not all builders construct homes in every BAL zone. For example, a lot of builders won't builds in BAL 40 or BAL FZ.

What Does It Cost to Build in a BAL Zone?

If your block falls in a BAL 12.5 zone – the most common – expect to pay around $5,000 depending on your builder and home size.

This cost covers additional construction requirements such as:

• Metal mesh screens on windows and doors

• Sarking (roof wrapping) across the full roof area

• Seals on garage doors and roof penetrations

• Minimum 4mm window glazing

• Fire-resistant weep hole covers in brickwork

• Upgraded external doors

• Anti-ponding board installation

• Copper feed lines to hot water systems

• Flashings for solar hot water panels

As you move up the BAL scale, the requirements – and costs – increase. For example, BAL 40 or Flame Zone may require metal frames and a non-combustible roof, which many builders cannot or will not provide.

How Do I Know My Block's BAL Rating?

It’s best to ask your builder to check. They’ll often use a government website to confirm your block’s classification. In Victoria, you can also check this yourself:

• Visit[ mapshare.vic.gov.au

  ](https://mapshare.vic.gov.au/)

• Type in your property address

• Enable the bushfire layer

• If your block is shaded brown, it’s in a BAL zone

• You can generate a free Property Report PDF from the site

Note: BAL classifications can change. If your land hasn’t titled yet and the surrounding area is undeveloped, the bushfire risk could reduce by the time you're ready to build – especially as more houses go up in the estate.

Are BAL Requirements Worth It?

BAL construction might seem like an unwanted cost, but it comes with benefits:

• Improved safety for you and your family

• Protection of your investment in case of bushfire

• Less dust inside the home due to roof sarking

• Long-term peace of mind

These requirements were introduced after the tragic Black Saturday fires in Victoria. The goal is simple – save homes and lives.

Tips for Home Buyers

• Ask early: Have your builder check if your land is in a BAL zone during the quoting stage.

• Expect variation: BAL costs can differ from builder to builder.

• Review the details: If you're paying for BAL compliance, ask what inclusions are covered.

• Factor it in: If you’re on a tight budget, knowing your BAL zone upfront can help you make smarter choices.

Key Takeaways

• BAL ratings assess your home's exposure to bushfire risks and dictate building requirements.

• BAL 12.5 is the most common in new estates and typically adds around $5K to the build cost.

• Requirements include fire-resistant features like screens, seals, sarking, and upgraded doors.

• Not all builders will build in high BAL zones – always check early.

• Use MapShare to check your block’s BAL rating yourself in Victoria.

• BAL zones can change as surrounding land is developed and titled.

• BAL upgrades not only provide safety but can improve comfort and reduce dust in the home.

Glossary of Terms

BAL (Bushfire Attack Level) – A rating system to assess bushfire risk and construction needs. AS3959 – The Australian Standard that outlines construction requirements for buildings in bushfire-prone areas. Sarking – A reflective foil insulation used under the roof to improve energy efficiency and fire protection. Weep holes – Small openings in brickwork that allow moisture to escape and require covers in BAL zones. MapShare – Victorian government mapping tool that includes bushfire overlays.

Frequently Asked Questions

Q: Do I have to comply with BAL if I’m in a low-risk area? A: If your property is classified as BAL Low, no additional requirements are necessary.

Q: Can my BAL rating change before I build? A: Yes. If your land hasn’t titled yet, the surrounding development can influence your BAL rating when it does.

Q: Can I avoid building in a BAL zone? A: It depends on where you want to live. Most new estates are designed to be low risk, but it’s best to check before you buy.

Q: Will my builder remove the BAL cost if the zone changes before permit stage? A: Often yes – if your block drops to BAL Low before building approval, your builder may remove the BAL-related costs.

Listen to the Full Episode

🎧 Bushfire Attack Level (BAL) - what does it mean?

About the Home Building Hub Podcast

The Home Building Hub podcast, hosted by industry experts Colin Bischof and Darren Brennan, is Australia’s premier resource for new home buyers. With weekly episodes featuring special guests, the podcast provides objective, high-quality insights into the home building process – completely free and without sales pitches. From understanding financing options to navigating the complexities of building a new home, each episode is packed with actionable advice and tips.

Explore more episodes at www.homebuildinghub.com.au and join our growing community of informed home buyers.

Disclaimer

Whilst we’re all about providing value to you, this article should not be considered as legal or financial advice. It contains general information only and is based on the content discussed during the podcast episode. This information is relevant to the episode’s release date and may not be applicable at the time of reading. Always seek independent professional advice tailored to your personal situation before making any legal or financial decisions.