The threat of bushfire in Australia is part of life, especially during the hot and dry summer months. The devastating consequences on houses and suburbs have become all too apparent in recent years, with the 2009 Victorian bushfires and 2003 Canberra fires resulting in enormous destruction and heartbreak.
As a result, Australian bushfire codes have been upgraded and increasingly enforced in areas where bushfire risk is evident. Compliance with the standard is required in construction of new buildings and certain renovations and extensions.
Owner-builder Peter Burton is building his own home in Berringa, a small township in west-central Victoria that has been subject to significant bushfires in the past, and knows all too well the challenges of building a home that can fight the elements.
He says there are three main factors you need to consider when building in a bushfire zone.
The first thing you need to consider when building a house in a bushfire zone is whether you can use the materials you’d really like. When selecting materials for his own house, Burton has had to ensure that everything that’s going to be used on the outside of the house isn’t flammable.
“You have to make sure that the materials you use comply with the 2009 bushfire code, which governs all new buildings,” says Burton.
For his own home, Burton used several James Hardie® products that were chosen for their non-combustibility and durability.
“You can’t use timber or any other combustible products otherwise you’ll almost certainly lose the home,” he says.
Deemed non-combustible by the Building Code of Australia, Scyon™ Matrix™ cladding, and Linea™ weatherboard and HardieFlex™ eave lining are ideal for use in Australian bushfire prone areas.
Materials aren’t the only things that need to be considered when designing homes in high fire danger areas. The areas in a home most vulnerable to direct ignition by ember are timber decks, eaves and gutters, and window frames.
Knowing how to manage the risk of ember attack is invaluable, but the solutions aren’t rocket science. Simple measures, like using aluminum on window frames, having a tight-fitting roof and fire-resistant eaves – all help protect a home against ember attack.
There are many design factors that impact on how a home will perform when under attack by fire. But what some people may forget to think about is how they can use the natural landscape to help defend their home.
According to the Australian Institute of Architects’ (AIA) Bushfire Design Guide, you should ensure there is enough cleared land between the house and the bush and avoid steep hillsides, as the intensity of the fire can double for each ten degrees of slope.
Builders must also consider the effectiveness of the siting of the home, defined defendable space, vegetation management, access and water supply, all of which Burton has addressed in the siting of his own home.
“The house is cut into the side of the hill on a cut/fill and land is cleared around it by a minimum of 12 metres, which provides defendable space and distance from flame and radiant heat,” says Burton.
“Position the house in a ‘pocket’ cut into the landscape helps to deflect embers, and we made sure that dense forest is at least 200m away.”