Appendix B - Bushfire Hazard Assessment · MCU26/0099

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2.5. National Construction Code 2022: Building Code of Australia

The National Construction Code 2022: Building Code of Australia (BCA) details technical provisions
pertaining to the design and construction of buildings and other structures throughout Australia including the
construction of buildings within bushfire prone areas.

2.6. Australian Standard: Construction of buildings in bushfire-prone areas (AS 3959-2018)

Where development is proposed within bushfire prone areas, AS3959-2018 specifies construction
requirements to better withstand attack from bushfire thus giving a measure of protection to the building
occupants (until the fire front passes) as well as to the building itself (AS3959-2018 p.5). Construction
specifications are based on heat flux exposure thresholds which have been categorized into six Bushfire
Attack Levels (BALs), listed in ascending order of threat level below:
    •   BAL- LOW
    •   BAL- 12.5
    •   BAL- 19
    •   BAL- 29
    •   BAL- 40; and
    •   BAL- Flame Zone (FZ)

These categories are expressed in kW/m², as such, the lower the category value the lower the radiant heat
exposure. The highest level of bushfire attack is BAL-FZ, which indicates direct exposure to flames.
Determining a BAL rating for a proposed development can be ascertained using either Method 1 (Clause 2.2,
AS 3959-2018) or Method 2 (Appendix B, AS 3959-2018). Method 1 is a simplified procedure, whereas
Method 2 is more detailed and is used when a more precise result is required, or when the parameters of the
site deem it necessary.


     3. BUSHFIRE HAZARD ASSESSMENT METHODOLOGY

3.1. Methodology

Assessment methodology for the subject site has been conducted in accordance with a Method 2 assessment
per the Australian Standard Construction of buildings in bushfire-prone areas (2018) including amendments,
and with reference to Bushfire Resilient Communities – Technical Reference Guide for the State Planning
Policy State Interest ‘Natural Hazards, Risk and Resilience – Bushfire’.

3.2. Desktop Assessment

A desktop assessment of the subject site and surrounds using high resolution imagery was conducted to
broadly assess the site characteristics and relevant information. QSpatial data was obtained to produce site-
specific Bushfire Prone Area (BPA) mapping per SPP and Maximum Landscape Slope and Vegetation
Hazard Class mapping per Bushfire Resilient Communities (2019). This is followed by an on-site field
assessment and ground-truthing.




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