Appendix B - Bushfire Hazard Assessment · MCU26/0099

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4.5. BAL Calculation

An AS3959 Method 2 calculation was performed using the inputs detailed above and summarised in Table 3
below. The result is BAL-19 for the proposed new dwelling (refer Method 2 Calculations using Fire Protection
Association’s (FPA’s) Flamesol Calculator in Appendix B).


          Table 3 – Summary information for Vegetation assessment (per AS3959 and BRC) and BAL calculations
Plot #    Vegetation Hazard      Vegetation       Vegetation Description                                 Distance     Effective     BAL Rating for
          Class (VHC) fuel       Classification                                                          between      Slope &       each Plot per
          loads                                                                                          Veg. Plot    Site Slope    AS3959-2018
                                                                                                         & Subject
                                                                                                         Site
Plot 1    VHC 16.1, from         Class B          Plot 1 Vegetation generally surrounds the subject      16m          Effective     BAL-19
          BRC:                   Woodland         site, most of the subject allotment is a working                    Slope: 5°
                                                  lime tree farm. Access to some areas of Plot 1
          Total surface fuels:                    vegetation was restricted due to its location within
          13.8 t/ha                               private properties, therefore Plot 1 vegetation                     Site Slope:
                                                  assessment has been aided by aerial imagery,                        Nil slope
          Total fuels: 26.0                       Slope and Vegetation Hazard Class mapping.
          t/ha                                    Plot 1 has an effective downslope up to 5 degrees
                                                  under the vegetation, per mapping. Plot 1
                                                  Vegetation consists of a dominant Eucalypt
                                                  canopy, with an understory juvenile trees and
                                                  grasses. Tree canopy foliage cover is ~30% and
                                                  tree height 10-30m+ at maturity.

Managed                          Excluded         All other areas surrounding the proposed subject       n/a          n/a           BAL-LOW
Areas                            Clause 2.2.3.2   site, within the assessment area, are exempt from
                                 (e) and (f)      classification as they consist of low vegetation
                                                  cover, highly modified vegetation that is
                                                  considered low threat (gardens and lawns),
                                                  gravel or sealed surfaces and other infrastructure
                                                  (houses, driveways, roads, etc).



Bushfire Attack Level (BAL) for the proposed new dwelling and associated infrastructure                                             BAL-19




4.6. BAL Construction Requirements

The BAL rating for the subject site has been calculated to be BAL-19. Shielding is not applicable for the
proposed new dwelling due to the line-of-sight exposure to a bushfire threat from all elevations per Clause
3.5 of AS3959-2018. As such the proposed new dwelling and associated infrastructure, will need to comply
with Section 3 and Section 6 of AS3959-2018.

It is important to note that this rating applies only if the separation distances specified in Table 3 are
maintained at all times. Any change/s to any of these, or the proposed new dwelling, and associated
infrastructure location will necessitate a recalculation of the BAL rating.

4.7. Maintenance of separation distances

The separation distances between the structure/s and the identified Vegetation Plots can be referred to as
an Asset Protection Zone (APZ). An APZ is a low/no fuel area surrounding the structure/s where the minimum
distance is measured on a horizontal plane from the nearest part of the external wall/supporting column or
stair of the structure to the edge of the unmanaged vegetation. An APZ is to be maintained in perpetuity;


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