Building on bushfire prone sites

About half of the houses that I design are on sites classified as bush fire prone. This is partly a reflection of the interesting projects that I get to work on, which are often near reserves or in bushy areas, but also because of new Australian standards that have resulted from catastrophic bushfire incidents in the last couple of decades. Typically the first step in the process is to engage an accredited bush fire consultant who will evaluate the site and provide a BAL ( bushfire attack level ) rating. These come in several categories – BAL 12.5, BAL 19, BAL 29, BAL 40 and BAL 40 + ( flame zone ) – note BAL29 = 29 kw per M2 of radiant heat. Most sites have 2 different BAL ratings, as the rating decreases with distance from the fire source, and orientation.

For each level, there are construction rules to be complied, and predictably, they become tougher as the BAL level increases. Generally it is easy to comply using readily available materials, and with negligible compromises to the design. Windows and doors for BAL 40 and FZ need to have been tested and certified, and the number that have been through this expensive process is steadily increasing as the market place responds to the new demands.

So in summary, this is one more hurdle to be jumped on the way to Council approval, but generally it is easy to deal with the correct procedure and attention to detail, and definitely for a worthy cause.