Understanding the BAL rating for owner builders in New South Wales is paramount. Reflecting on the 2001 Christmas fires in Sydney, which left 109 homes destroyed and over 750,000 hectares burnt. Because of this, the NSW government instituted a Joint Parliamentary Inquiry. Consequently, this led to the endorsement of “Planning for Bush Fire Protection” (PBP).  As a result, the current legislation being PBP 2019, adopted on March 1, 2020. In recovery, prospective owner builders in NSW must now understand and navigate the Bushfire Attack Level (BAL) ratings. Which are pivotal in ensuring building safety in bushfire-prone areas.

NSW Forefront of Bushfire Protection

New South Wales has been at the forefront of bushfire protection, since adopting the Australian Standard AS 3959-2018 on March 1, 2020, in alignment with PBP 2019 requirements. The comprehensive framework categorises sites into six levels. In essence, each dictating specific construction requirements based on factors, such as, vegetation types, distance from vegetation, slope of the land, and the Fire Danger Index (FDI). Understanding and accurately determining the BAL is crucial for owner builders in NSW to implement the appropriate construction methods and ensure home safety.


Six Steps to a Successful BAL Assessment in NSW

  1. Determine your Fire Danger Index (FDI), considering NSW’s generally high FDI, especially in alpine areas.
  2. Identify your site’s vegetation types, classifying vegetation based on tables provided in the Standard, with exclusions for specific types.
  3. Measure the distance from the site to vegetation, considering horizontal measurement excluding certain features.
  4. Determine the slope of the land under vegetation, assessing the slope’s impact on bushfire severity.
  5. Assign the BAL using tables corresponding to FDI, upslope or downslope, vegetation type, and distance.
  6. Apply construction requirements from AS 3959-2018 for increased protection against bushfire threats.

Understanding BAL Ratings in NSW:

  • BAL-Low: Insufficient risk to warrant specific construction requirements.
  • BAL-12.5: Ember attack with increasing heat flux.
  • BAL-19: Increased ember attack and burning debris, higher heat flux.
  • BAL-29: Further escalation in ember attack and heat flux, potential flame exposure.
  • BAL-40: Direct exposure to flames, high heat flux, and ember attack.
  • BAL-FZ: Extreme risk with direct exposure to flames.



All things considered, by diligently following these six steps and adhering to the construction requirements outlined in AS 3959-2018, owner builders in NSW can navigate the BAL assessment process successfully.  Consequently this contributes to creating safer and more resilient homes in bushfire-prone areas. For additional information, individuals can contact an Owner Builder Coach or relevant authorities or refer to the NSW RFS publications for guidance.

Builder Checklist 14-Day FREE Trial     

Please complete this form to enjoy a 14-day FREE Builder Checklist trial.
Contact Email  *
First Name *
Last Name *
Phone *
*Required Fields

Suffering From
Owner Builder Insomnia?


Owner Building
Is It Right For You?