Information Response - Email 1 of 2 MCU16/0153 & REC16/0041

5.3        Bushfire Attack Levels and Construction Standards
5.3.1        Background
Australian Standard 3959 (2009) Construction of buildings in bushfire-prone areas provides
minimum construction standards for new dwellings in designated Bushfire Prone Areas. The
construction standards are intended to improve the performance of buildings subjected
to burning debris, radiant heat or flame contact. The AS3959- 2009 methodology
prescribes Bushfire Attack Levels (BAL’s) to the facades of proposed buildings to which
corresponding construction safety standards are applied. AS3959-2009 defines Bushfire
Attack Levels as:

           ‘A means of measuring the severity of a building’s potential exposure to ember
           attack, radiant heat and direct flame contact, using increments of radiant heat
           expressed in kilowatts per metre squared, which is the basis for establishing the
           requirements for construction to improve protection of building elements from
           attack by bushfire.’

Table 9 describes the range of available BAL’s and their related degree of potential
severity.

                        Table 9 – Description of Bushfire Attack Levels (BALs) (AS3959- 2009)
                     Heat flux exposure thresholds of   Description of predicted         Construction Section
Bushfire Attack
                     classified vegetation within       bushfire attack and levels of
Level (BAL)
                     100m of the site                   exposure

                                                        There is insufficient risk to
BAL- LOW                   See Clause 2.2.3.2           warrant specific construction              4
                                                        requirements

BAL – 12.5                     <12.5kW/m2               Ember attack                            3 and 5

                                                        Increasing levels of ember
                              >12.5kW/ m2               attack and burning debris
BAL - 19                                                ignited by windborne embers             3 and 6
                               <19kW/m2                 together with increasing heat
                                                        flux

                                                        Increasing levels of ember
                               >19kW/ m2                attack and burning debris
BAL - 29                                                ignited by windborne embers             3 and 7
                               <29kW/m2                 together with increasing heat
                                                        flux

                                                        Increasing levels of ember
                                                        attack and burning debris
                               >29kW/ m2                ignited by windborne embers
BAL - 40                                                together with increasing heat           3 and 8
                               <40kW/m2                 flux with the increased
                                                        likelihood of exposure to
                                                        flames

                                                        Direct exposure to flames
BAL - FZ                       >40kW/m2                 from fire front in addition to          3 and 9
                                                        heat flux and ember attack




                                        Bushfire Management Plan
February 2015                                                                               Page 24
                                   215 David Low Way, Peregian Beach
                                         Scanlon Property Group