Can my garden design effect my bushfire rating?
You might think your BAL rating will be determined by the stand of bushland up the road, and its likely you are right in most cases. But don’t neglect the “bushfire vegetation” that could be right on your doorstep – namely, your garden (and yes, even your lawn).
If your property is in a bushfire area then your garden can be a threat if it is not maintained to the correct standard. The result could be increased risk to your life and property, and increased costs if you are required to build to a higher standard.
So how do you ensure your garden is kept as a low threat?
The simple answer is to maintain the area surrounding your property to the standards required of an Asset Protection Zone (APZ). These standards are included in the appendices to the WA Guidelines for Planning in Bushfire Prone Areas, which include:
Trees (> 5 metres in height): trunks at maturity should be a minimum distance of 6 metres from all elevations of the building, branches at maturity should not touch or overhang the building, lower branches should be removed to a height of 2 metres above the ground and or surface vegetation, canopy cover should be less than 15% with tree canopies at maturity well spread to at least 5 metres apart as to not form a continuous canopy.
Shrubs (0.5 metres to 5 metres in height): should not be located under trees or within 3 metres of buildings, should not be planted in clumps greater than 5m2 in area, clumps of shrubs should be separated from each other and any exposed window or door by at least 10 metres. Shrubs greater than 5 metres in height are to be treated as trees.
Ground covers (<0.5 metres in height): can be planted under trees but must be properly maintained to remove dead plant material and any parts within 2 metres of a structure, but 3 metres from windows or doors if greater than 100 millimetres in height. Ground covers greater than 0.5 metres in height are to be treated as shrubs.
Grass: should be managed to maintain a height of 100 millimetres or less.Fine Fuel load: combustible dead vegetation matter less than 6 millimetres in thickness reduced to and maintained at an average of two tonnes per hectare.
If any of the above items are not met then you are potentially at greater risk should a bushfire occur in your area. On the other hand, adhering to the above standards is best practice to maintain the surroundings of your building in a low threat condition.
Jeremy Durston (BPAD36525)