Research has been carried out by the Local Councils throughout Western Australia to determine areas at risk of bushfires. The Building Code of Australia 2012 Part 22.214.171.124 Bushfire Areas, states that it is a requirement of AS3959 ‘Construction of Buildings in Bushfire –Prone Areas’, that any residential development located within a designated bushfire prone area must meet the minimum construction standards pertaining to the applicable BAL rating.
If you are located within a bushfire prone area and are looking to build a new home, subdivide your property, or simply wanting to build that new shed or extension then it is likely that you will require a Bushfire Attack Level (BAL) assessment or a Bushfire Management Plan (BMP).
A BAL Low rating suggests that there is insufficient risk of fire from embers, radiant heat or flames to warrant specific construction requirements.
A BAL 12.5 rating carries a sufficient enough risk of fire from embers or burning debris requiring your build to meet certain construction requirements.
A BAL 19 means that there is sufficient cause for concern due to increased radiant heat and ember attack that will require your build to use building materials that will prevent damage and the spread of a fire, if one was to occur.
Buildings with a BAL 29 rating are at a serious risk of catching fire due to burning debris and increased heat flux. With BAL rating of 29 there is also a risk of the building becoming exposed to flames. Ember and radiant heat protection are required in the construction of buildings that are rated BAL 29.
BAL 40 carries all the risks of BAL 29 except that the risk of exposure to flames is now significantly increased. Construction requirements include using materials that are highly resistant to flames. Eliminating elements which promote the spread of flames, embers and radiant heat is also recommended.
BAL FZ – or Flame Zone – represents a direct threat to buildings and residents. Significant protection is required to reduce the threat, such as radiant heat barriers and modifications to the building and surrounding property. If at all possible, it is recommended that you do not build your home in a designated Flame Zone.
The new legislation is primarily aimed at improving the ability of buildings in designated bushfire prone areas to better withstand attack from bushfire, therefore giving better protection to the building occupants, as well as to the building itself.
A BAL assessment is a means of measuring the severity of a building’s potential exposure to ember attack, radiant heat and direct flame contact. It is the basis for establishing the requirements for construction to improve protection of building elements from attack by bushfire.
A Termico FPA accredited assessor will attend the site location, and using the proposed site plans they will assess the level of risk to the proposed building based on the surrounding vegetation and overall landscape
Following the site visit the assessor will complete a comprehensive Bushfire Attack Level (BAL) report as per AS 3959-2009, which will outline their findings and provide an overall BAL rating
This BAL rating determines what materials will be required to reduce the potential risk to the building and its occupants
Site assessment and Nearmap image - this shows the proposed building site together with the surrounding vegetation. It shows the distance to the vegetation and the direction in which the photos, included within the report, were taken from site.
Vegetation classification and effective slope assessment - Shows photos of the vegetation within 100 meters of the site together with the classification of the vegetation and a measurement of the slope on which the vegetation sits.
Relevant fire danger index – shows the fire danger index (FDI) for the site.
Bushfire attack level assessment for each area of vegetation – indicates the BAL rating for each area of vegetation within 100 meters of the site
Determination of the appropriate construction requirements – provides the overall BAL rating for the site and outlines the sections of the standard that apply to the construction of the dwelling.
Proposed site plan – shows the areas of the dwelling that may be shielded from the predicted radiant heat levels and therefore may have a lower BAL resulting in less stringent building adjustments.