BUSHFIRE DESIGN UPDATE
At the beginning of 2020, Australian firefighters brushed the sweat off of their brows as they braced themselves for another horror bushfire season.
As a nation that has historically been prone to bushfires and its fatal repercussions – shown through the 2009 Black Saturday bushfires
– it is curious as to how initiatives like the Victorian Bushfire Reconstruction and Recovery Authority’s We will Rebuild initiative, stopped short after a mere 19 pro bono designs, and even fewer houses materialised thereafter.
With renowned firms such as Donnovan Hill and John Wardle involved, and an increasing popularity in the supply and demand for bushfire resistant products on the market, the question must be asked: Why are bushfire resistant homes so scarce in Australia?
Research architect and spokesman for the Bushfire Building Council of Australia (BBCA), Dr Ian Weir, says, “Architects work in a bit of a rarefied atmosphere and I don’t think the quite speculative designs from that initiative resonated with the mums and dads that the scheme intended to help.”
After Black Saturday, Weir pointed to architect Glenn Murcutt for bushfire resistant designs in mainstream media’s coverage of the crises.
With Murcutt’s innovations utilising black ceramic house tiles, sprinkler systems, leafshedding gutter designs and flat-roof water features in the 20th century, it is only to be imagined what could be achieved in 2020.
Weir, having previously believed in 2016 that the bushfire resistant home designs could have been too ‘prototypical and expensive’, also stated that the designs seemed to some, ‘a bit foreign, a bit alien.’
But in 2020, Weir states that these are a part of a number of misconceptions, “One – that we simply can’t build any house to withstand the fire events we are currently experiencing (catastrophic conditions). Surprisingly, many architects unfortunately share this view.”
“Two – that any house designed to the standards is going to be cost prohibitive. This is warranted for BAL-FZ homes but building in bushfire prone areas attracts a cost premium anyway due to other factors such as remoteness, slope, distance to services and the need to harvest water.”
“Three – people assume they would have to live in a bunker-like structure.”
“And the last perception, which is valid, is that people don’t want to clear massive areas around their homes just for bushfire safety because it destroys the amenity and the very reason they chose the site in the first place.”
In 2013, architecture critic Philip Drew argued that entirely bushfire-proof communities need to be built. And perhaps he had a point
– as six years, 10 million hectares and 2,500 homes later, Australia finds itself reaching for its closest concrete-walled haven.
The Bushfire Building Council of Australia (BBCA) estimates a percentage of only 10 percent of bushfire resilient homes exist in bushfire prone regions in Australia.
“The BBCA is garnering support with state and federal governments for a five-star rating scheme, whereby entire communities can be assessed for their bushfire resilience, and then the best, most cost-effective methods of mitigating against bushfire can be strategised.”
Weir says the scheme addresses the national problem of exceptionally poor integration between the NCC which deals with buildings, and the various state planning policies, which deals with large-scale subdivision design.
Alongside Weir’s speculation and proactive steps towards safeguarding Australia’s homes, he practices what he preaches – his Karri house, which boasts large glass sliding doors protected by steel mesh, and Ocean Fire house, are both strategised responses to the nation’s repetitively fiery climate.
But as Weir mentions, the tragedy-bred trend of building bushfire resistant homes has become a challenge for architects; navigating the majority’s perception of bushfire resistant homes equalling to a ‘boring’ bunker style, as opposed to a beautiful house.
Field Office Architecture’s Mount Macedon house has since offered confidence in the balance of beauty and bushfire resistance in its use of non-combustible materials.
With Corten (rusting steel) cladding wrapping the building and settling into its natural environment, its shutters provide protection to the glazing behind it, with steel mesh screens over living areas designed to balance natural light and protection.
Similarly, the Mercieca family, who created Australia’s first passive house to meet the development requirements for the highest bushfire risk rating, has fire resistant cladding and triple-glazed windows.
The house survived fires that swept through the Blue Mountains in 2013, and only costs the equivalent to a cup of coffee a day to run.
With brick being a traditionally popular option for those less enticed by the modernised ‘bunker’ – mortar and brick, a fire-rated roof and bushfire shutters are a considerable compromise in the happy medium of a modern classic that the contemporary frontage, Stewart House, provides.
And even metropolitan designs such as the recently built Protagonist by Cumulus Studio at the Arts Centre Melbourne using Kaynemaile
– a polycarbonate chainmail mesh which is a secure, fire and UV resistant product – is to be taken a leaf from.
As ember attack is the primary cause for the loss of thousands of homes during the bushfires’ havoc, practicality over the wooden porch seems rife (and legally binding) in BAL40 zones.
Weir adds, “The cheapest thing to do is exclude verandahs and decks, and work with either the verandah being internalised or have masonry terraces – integrating landscape design with the house design as a first principle.”
“For the Karri House, we found that the BAL40 specific requirements added 3 percent to the construction cost, but this would have been much less if the house did not have to be elevated above the ground due to the steep slope.”
“The next is to eliminate all combustible materials and use products such as corrugated steel on steel wall framing – this is applicable up to BAL-40 and FZ in some instances.”
Rammed earth also has numerous benefits including its non-combustible and high-in-thermal-mass features, and is simpler to construct and durable (when protected adequately), so houses like Bush House by Archterra Architects inspire the simplicity yet modesty of a natural-material feel.
And so does limestone – with insulated framed walls, cement rendered walls and concrete floors, Wall and Wall House by Dane Design Australia pervades the simplicity of natural materials to blend into its environment, yet aesthetically peacocks its groups of blade walls.
No matter the materials you use, “think beyond the paradigm of the timber hideaway in the bush.”
“Understand that living in bushland settings is an immense privilege and with that comes responsibility – build houses that don’t contribute to the fire front.”