Bushfire Report · MCU26/0104

Bushfire Report


3.3 AS 3959 Construction of Buildings in Bushfire-prone Areas
Where development is proposed in designated bushfire prone areas, AS 3959:2018
provides construction requirements designed to enhance resistance against bushfire
attack. These construction specifications are determined by specific heat flux
exposure thresholds and are categorized into six Bushfire Attack Levels (BAL):

                             Radiant Heat
 Bushfire Attack Level                                    Description of Predicted
                              Exposure
        (BAL)                                      Bushfire Attack and Levels of Exposure
                            (AS3959:2018)
                                              Minimal attack from radiant heat and flame due to
                                              the distance of the building from the vegetation,
       BAL – Low              Insignificant
                                              although some attack by burning debris is possible.
                                              There is insufficient threat to warrant specific
                                              construction requirements

                                              Attack by burning debris is significant with radiant
                                              heat (not greater than 12.5kW/m²). Radiant heat is
       BAL - 12.5           0 to 12.5kW/m2    unlikely to threaten building elements (such as
                                              unscreened glass). Specific construction
                                              requirements for ember protection and accumulation
                                              of debris are warranted.

                                              Attack by burning debris is significant with radiant
                                              heat flux (not greater than 19kW/m²) threatening
        BAL - 19           12.5 to 19kW/m2
                                              some building elements (such as screened glass).
                                              Specific construction requirements for embers and
                                              radiant heat are warranted.

                                              Attack by burning debris is significant and radiant
                                              heat flux (not greater than 29kW/m²) threatens
        BAL – 29            19 to 29kW/m2
                                              building integrity. Specific construction requirements
                                              for ember and higher levels of radiant heat are
                                              warranted. Some flame contact is possible.

        BAL – 40            29 to 40kW/m2     Radiant heat flux and potential flame contact could
                                              threaten building integrity.


                             40kW/m2 plus     Significant radiant heat and significantly higher
        BAL - FZ                              likelihood of flame contact from the fire front will
                           (Flame Contact)    threaten building integrity and result in significant
                                              risk to residents.



             Table 1: AS3959:2018 Using BAL to determine construction requirements



3.4 Noosa Shire Council Planning Scheme
Relevant bushfire provisions of the Council’s Planning Scheme reflect SPP State
and Local level interests by identifying designated bushfire prone areas. Where
assessable development is proposed on land mapped as containing bushfire hazard
areas, a site-specific bushfire hazard assessment prepared in accordance with the
planning scheme is required.


Max Bushfire Protection Consulting                                                                    13