Credit: Andrew Halsall / Ian Wei
The Australian architects designing homes to withstand bushfires
It wasn't that long ago that Australia was mired in what many assumed would be the country's worst crisis of 2020.
Lightning strikes ignited fires that swept across southeastern Australia, burning at least seven million hectares of land dried by years of drought and destroying around 3,000 homes.
Thousands of people were forced to seek temporary accommodation in rental properties and hotels. Many are still there, listening to daily reminders to "stay at home" to stop the spread of the coronavirus. If only they could.
Rebuilding after a bushfire can take months, if not years. Insurance assessments need to be carried out, land cleared, boundaries redrawn and essential services like electricity and water reconnected. Plans need to be drafted, costed and approved.
But most importantly, homeowners need to decide if they're willing to stay and risk losing everything all over again.
"A lot of people are coming to grips with what's happened, and the level of trauma is still very high," said architect Tim Lee, who was conducting how-to-rebuild seminars in fire-hit towns in New South Wales before coronavirus isolation measures forced everyone indoors.
Many Australians choose to live near the bush to feel closer to nature. They often live in wooden dwellings, sometimes down quiet, unsealed roads surrounded by trees.
It may seem peaceful but consultants SGS Economics & Planning estimates that at least 2.2 million Australians who live in these areas are at high and extreme risk of losing their homes to bushfires.
That's because the vast majority of their houses were built decades ago, before the current building standards were introduced, and when little thought was given to fire.
But with the climate crisis producing hotter, drier conditions, architects say it's more important than ever to design for bushfires before they become more intense and even harder to control. And they say it's possible to create a fire-resistant home that doesn't resemble a bunker -- one that works with the landscape rather than adding fuel to a raging fire.
Losing a home
In Australia, bushfires have their own season. The most recent spell ran from June last year to the last week of March 2020, taking in winter, spring and the whole of summer, when temperatures in some places reached record highs. It followed the driest year since records began in 1900. At least 34 people died.
The most deadly bushfire crisis on record was in 2009 when flames ripped through the state of Victoria, killing 173 people.
Merran and Peter Guest lost their home in the small Victorian town of Marysville on February 7, a day now known as Black Saturday. They left their home that morning to drive two hours to a party in Melbourne, unaware that a fire was approaching. Back then, there were no text messages or alerts warning of an imminent fire threat, as there are today. By the time they were allowed to return to their home, nothing was left.
"Everything that survived, when you picked it up it just turned to dust," Merran Guest said.
The Black Saturday fires forced an upgrade to Australia's national bushfire building regulations. Now, building sites are assessed for their fire risk according to six "Bushfire Attack Levels" from BAL-Low (very low risk) to BAL-FZ (extreme risk), also known as flame zone sites.
At these sites, direct contact with flames is considered "likely," along with high levels of radiant heat and ember attacks -- burning projectiles that start new fires, kilometers ahead of the firefront. Plans in flame zones must be approved in advance so that every aspect of the house is certified as non-combustible. Metal bushfire shutters are now mandatory.
However, with millions of Australian homes in moderate to extreme fire-risk areas, retrofitting them to meet current standards is all but impossible, said architect Nigel Bell of ECOdesign Architects + Consultants.
"You cannot, no matter how much money you've spent, upgrade it without demolition," said Bell. "If you've only got $5,000 or $20,000 to spend, probably one of the best things you can do is to add a water spray sprinkler system."
Kate Cotter, CEO of the Bushfire Building Council of Australia, says improving existing homes, even with simple measures such as sealing gaps and replacing flammable material, is a matter of national urgency. "Ignoring legacy property ignores the majority of the risk," she said.
Design as a barrier
New homes in high fire risk areas not only have to meet strict Australian building standards, but extra measures imposed by some states.
For example, the New South Wales Rural Fire Service encourages homeowners to clear trees within a 10-meter radius of their home, and vegetation within 50 meters, by making it legal to do so without council approval.
Architect Ian Weir fears the emphasis on clearing land creates a false sense of security for homeowners, when research shows that at least 85% of homes are lost to ember attacks.
"People might not even smell smoke, and suddenly their immediate landscape around the building is on fire," he said. "In the majority of sites across the whole country, fire authorities are encouraging the management of sites, as opposed to the design of resilient homes."
Clever design can help reduce the risk of fire, without razing surrounding land, he said. For example, traditional wooden decks can be replaced with terraces, if the land is flat enough, and internal courtyards can be used to bring nature inside without compromising safety.
"We can get those kind of verandah-style spaces actually within the interior of the house," Weir said.
One of Weir's most recent prototypes is "Camera Botanica," a house with three layers of defense: a two-millimeter-thick semi-reflective exterior of galvanized steel covering bushfire-proof fabric that lies above non-combustible mineral wool insulation. The three layers protect the timber frame, and includes jarrah and wandoo, naturally fire-resistant hardwoods.
The prototype resembles a small oven, but the logic behind this house is that its occupants can lock it up and leave.
"Almost 50% of the wall surface area opens up to the landscape but (it) closes down to create a fully enclosed shield from embers, radiant heat and flames," Weir explained. "It is not intended to protect occupants -- instead the occupants can close it down and leave early."
The position of the house is important, too, said Bell of ECOdesign Architects + Consultants.
It should be low-set, especially the part of the house exposed to a potential firefront, and built on lower ground. "The worst thing you could do is build high on top of a hill or a mountain with bushfire-prone vegetation below," Bell said.
Fire resistant materials
New materials are also making homes more fire-resistant.
Architect Jiri Lev describes hempcrete as a "miracle material" that's both non-flammable and eco-friendly. Made from industrial hemp, a lime-based binder and water, it is squashed into a wooden frame and, once dry, creates an effective barrier against flames.
"Once you finish with a house like that, you can just crush it and it will turn into soil again, or you can take the walls apart, crush the material and use it in a new house," said Lev, the founder of Architects Assist, which offers pro bono architectural advice for bushfire victims.
Lev says there needs to be a complete rethink of architecture in Australia, which he said has created "commodified, uniform dwellings" that are disconnected from the land and local conditions.
"It's always about building the biggest for the cheapest. Of course with that attitude and approach, you can never end up with a beautiful home or a beautiful suburb," Lev said.
His vision for bush architecture is a blanket of small townships, each flanked by agricultural land and bush that's close enough to be managed by the community to regulate the threat. Lev said it would require a change in thinking, from seeking solitude in the bush to building homes closer together to make communities safer and more efficient.
"Everyone tends to want to live like the nobleman, have their own little duchy or their own little barony, even if it's just a quarter acre or less," he said. "People naturally try to create their own little isolated universe, but it's not sustainable. And it makes no sense. In the end of there's no sustainability in isolation."
His point seems more pertinent now than ever. Designing a new home may seem exciting, but for many people who are rebuilding after a fire, it's a painful and daunting experience.
"You've got people who've been in their houses for 20 to 30 years, then all of a sudden it's gone," said Tim Lee. "There's a grieving process to go through. Many people just want their old house back."
Merran and Peter Guest did, too. The house they lost was less than 10 years old. They still had the plans and asked the builder to construct another one -- but to make it bigger and more fire resistant.
The old marine plywood was replaced with rendered brick, all the windows were double-glazed and now the only wood in the house is the front door, made of merbau, a fire-resistant hardwood.
"Because we built the house, we knew what it cost. But many people had bought a house for not a lot, so they'd only insured it for a little bit -- and they didn't have money to build to the new specifications," Merran said, adding that if she had her time again, she wouldn't rebuild. The process was time-consuming, costly and confusing.
"If we had known what we'd go through rebuilding, we wouldn't have done it. But now we have, I'm glad we did it."