A BAL Contour map is an essential tool for site planning for anyone looking to build a home in a bushfire-prone area. Understanding the details within a BAL Contour map ensures you choose the safest, most cost-effective location for your dwelling. By using this map early in the design process, you can minimize risks, lower build costs, and streamline approvals.
What is a BAL Contour Map?
A BAL Contour map graphically shows the Bushfire Attack Level (BAL) across a property. It uses a range of colours and contour lines to indicate how close the property is to bushfire hazards, such as forested areas outside the lot. Understanding these zones is critical for anyone considering building in the bushfire prone area.
Understand that in most cases the BAL Contour will only show you the impact from outside your lot giving you the most suitable or compliant location, not the “determined” BAL Rating, vegetation modification may need to occur within your lot to get a building permit.
Why the BAL Contour Map Matters
The BAL Contour map site planning not only reveals the fire risk across your property from outside factors but also informs exactly where to position your house for maximum safety or compliance.
The different contour colours correspond to varying BAL ratings—yellow shows moderate risk (BAL-29), while shades like orange or red indicate higher danger zones (such as BAL-40 or BAL-FZ).
Each colour signals required setbacks, so careful placement within the safest zones can result in significant savings and ease of mind.
If your dwelling is in the BAL-40 or FZ area you may be unable to build, it could be expensive or can significantly slow down the process.
Advantages of Early Access to BAL Contour Map Information
Having the BAL Contour map site planning information at the start of your building project brings enormous benefits:
- Informed decision making: You can choose the safest, most cost-effective site for your home.
- Money savings: Locating your dwelling in low-risk areas can provide reduced construction costs and streamlined compliance.
- Time Savings: save time by finding the most suitable location on the first go without having to redraw your plans.
- Simplifies approvals: Early understanding of BAL levels helps avoid costly design changes later, making council approvals smoother and faster.
Understanding Contour Map Colors
The colors on a BAL Contour map site planning tool are crucial. Generally:
- Blue(s): Lower bushfire risk (BAL-LOW, BAL-12.5 or BAL-19)
- Yellow: Moderate risk (BAL-29)
- Orange or Red: Extreme risk (BAL-40, BAL-FZ, or Flame Zone)
Placing your dwelling, additions or associated structure in a BAL-29 or less can drastically lower construction costs or complexity and improve safety.
Below is an example, the distances will change with each individual site, vegetation classification or effective slope.
Bushfire Hazard Level (BHL)
Don’t confuse BAL with BHL as these are very different things entirely, sometimes the site may have a BHL of LOW, example below where “Moderate, low” is not the BAL Rating (Shire of Mundaring Mapping):
Risks of Building Too Close to Boundaries
If your dwelling is sited too close to a property boundary, you may inadvertently step into a higher BAL zone. This increases construction costs, design requirements, may decrease your available options for windows and materials or even halt your build.
Ensuring the right setback from boundaries will protect both your wallet, your family and ensure compliance for insurance into the future.
If there is no option but to be close to the boundary then we can design to suit the dwelling and the location, possibly by isolating parts of the dwelling in BAL-40 or FZ eg:
Conclusion
Using a BAL Contour map site planning strategy is vital for anyone building in bushfire-prone area. The map’s information enables smarter location choices, reduces costs, and provides peace of mind. Always start your planning process with a detailed assessment using this vital tool if we advise you to do so.
If you would like to understand more about the process of construction in the Bushfire Prone Area, please check out our other blogs that include: