Now called ‘the black summer’, Australia’s bushfire season from 2109 to 2020 was the worst on record. Quite simply, the fires were unprecedented. By March 2020, 18.6 million hectares had been burned, more buildings had been burned (including 2,779 homes) and, most tragically, 34 people had lost their lives. On top of that, nearly 3 billion animals, including threatened or endangered species, have been killed or relocated.
Given Australia’s love of our native bushland and our tendency to build homes as close together as possible, that figure of 2,779 homes destroyed could easily have been higher. If there’s a silver lining in drawing fires, it’s that over the past few years we’ve begun to better understand how to build a bushfire-proof home.
Designing a bushfire safe house – building in bushfire prone areas
How do you know if your house (or the land you want to build a house on) is in a bushfire zone? Applicable planning regulations vary by state (for example, in New South Wales you must contact the New South Wales Rural Fire Service, while in Vic the competent authority VicPlan) .
If you are found to be in a bushfire area, if you wish to carry out any construction or renovation work, you should undertake a Bushfire Attack Level (BAL) assessment. This is to determine the appropriate measures to follow to ensure that the house is protected against a possible bushfire. For example, BAL 40 building requirements are stricter than BAL 12.5 building requirements.
A home’s rating level measures the severity of its risk of attack by embers, radiant heat, and direct contact with flames. BAL is measured in terms of radiant heat (kilowatts/m²).
Here are the relevant BAL notes:
- Bal LOW: Very low risk
- BAL 12.5: Low risk
- BAL – 19: Moderate risk
- BAL 29: High risk
- BAL 40: Very high risk
- BAL FZ: extreme risk
What materials are good for a bushfire safe house?
Although there is no such thing as a flame zone kit, by choosing materials carefully, specifiers can greatly improve their expertise in designing bushfire proof homes.
Cladding – When it comes to exterior cladding, corrugated iron is a good choice for a fire-rated house, as are some types of fiber cement panels.
framework – Care should be taken when using timber for decking etc. Fire resistant woods include turpentine, red ironbark, blackbutt, merbau, red river gum. mottled gum and silver ash are recommended for house designs for bushfire areas.
Windows and glazing – It is advisable to install exterior metal shutters on all windows. In terms of window frame materials, aluminum and metal-reinforced PVC are recommended.
Steel frames – Steel frames are a good choice as they are extremely durable and fire resistant.
Exteriors – Apart from this, it is also important to consider gardens and landscaping. Always ensure there is a 5m space between the house and the garden and place the house as far away from native trees as possible, ensure gutters are regularly cleaned of fuel.
Install a sprinkler system – An important feature of a fire rated home is a sprinkler system. These need to spray water which is usually under pressure at 300kpa.
There are several myths and misconceptions surrounding bushfire proof homes, among those who are unfamiliar with their construction. The most popular of these is that bushfire proof homes always end up looking like a bushfire bunker. In reality, unless they are in the most dangerous places, they look a lot like standard houses. Even if you live somewhere like Kinglake, a town devastated by the 2009 Black Saturday fires, you can still build a bushfire safe home.
Bushfire proof house design – 10 of the best bushfire proof houses
1. Durimbul Bushfire Resistant House
Located in Wye River, Vic and designed by Matt Goodman Architect, the Durimbul Bushfire Resistant House was built to replace a house that was destroyed in a bushfire in 2015. Although perched on the side of a hill, it resists the fire.
2. Bellbird Retirement Home
Located in Killarney in Queensland’s Gold Coast Hinterland, this retreat by Steendijk Architects combines a rugged, fortress-like exterior with a beautiful, light-filled interior. Its most striking feature is its bushfire resistant roof.
4. Sydney Blue Mountains House
Designed by Urban Possible, this three-bedroom single-storey weekend was designed to deal with possible bushfires. For example, instead of having several windows, there are several hinged doors with double tempered glass three meters high.
5. Mount Macedon House
Designed by Field Office Architecture, Mt Macedon House, located in Victoria’s Macedon Ranges, features noncombustible materials and meticulous detailing. For example, it is clad in Corten cladding.
6. Karri Fire Station
Located on a BAL 40 property, this house by Ian Weir is built on stilts and has several fire-resistant features such as cavity masonry walls, concrete slabs and shutters on the windows to negate the effects of heat and flames.
7. House H
Also by Ian Weir Architect, H House is designed to sustain itself (without any human assistance) during a bushfire. Led by Dr Ian Weir, research architect and lecturer from Qld University of Technology (QUT), H House presents a model for reconciling bushfires and diversity with everyday life. H House is located within the bushfire-prone biodiversity landscape of Point Henry, WA.
8. The Christmas Hills House
Designed by architect Clare Cousins and located in the Christmas Hills town of Vic, this home replaced a home that was destroyed in the infamous Black Saturday fires. It meets the requirements for BAL-29, which is the second highest bushfire attack level.
9. Ball-Eastaway House
Located in Glenorie, a northwestern suburb of Sydney, New South Wales, the Ball-Eastaway house was designed in 1980 by Glenn Murcutt, who was something of a pioneer in bushfire-resistant homes. Its features include innovative leaf gutter designs, black ceramic house tiles that reflect radiant heat, sprinkler systems and rooftop water features.
10. Compressed Earth Bushfire Resistant House
Winner of the Bushfire Building Council of Australia’s Innovation Award for Best Design Concept in 2015, this home by Baldwin O’Bryan Architects is FZ – Flame Zone certified, which is the highest bushfire attack level in Australia. It incorporates a low-cost building block scheme based on stabilized compressed earth blocks, which the architects devised. This system is not only highly durable, but also considerably cheaper than reinforced concrete.