‘Some homes weren’t designed with fire in mind’: Is timber to blame for LA wildfires?

Amid the suburban carnage of the burnt-out Pacific Palisades, a solitary home still standing in the ruins turned the heads of passersby and caught the internet’s attention.

Architect Greg Chasen posted a photograph of the mini miracle to X last week. “Some of the design choices we made here helped,” he wrote. “But we were also very lucky.”

A Californian architect says the design choices they made on this client’s house helped it withstand fire.Credit: X/@ChasenGreg

Many Australians seeing images of the devastating blazes in Los Angeles – entire streets and blocks flattened by fire – might wonder whether these homes are being built in a way that makes them especially susceptible to fire.

The answer is, as usual, complex. It is true the United States is heavily reliant on timber framing for residential construction, as the National Association of Home Builders consistently reports that at least 90 per cent of new single-family homes are made from timber. But that’s not unusual: in Australia, the Housing Industry Association says about 80 per cent of detached homes here use timber frames, too.

Timber is particularly popular in earthquake-plagued California because of its flexibility. Most LA houses are timber-framed with an exterior, or siding, made of stucco – a fire-resistant, cement and sand-based render that is also one of the most common building materials in the US.

(In his memoir about growing up in southern California, Holy Land, writer D. J. Waldie described the ubiquitous and affordable stucco as “the suburban Carrara marble”. A cheap timber and stucco house was the best place to be in an earthquake, he wrote, and it tied into the mythology of LA as “an insubstantial place”.)

The timber and stucco combination isn’t necessarily bad. The surviving house in the Palisades was made from a timber frame set on a concrete slab foundation. “The walls were fire-rated, and the finishes were either cement, stucco or a low-flame-spread wood,” Chasen told this masthead.

The home also had some separation from its neighbours, a concrete perimeter wall, no attic vents or eaves and non-combustible roofing, which is standard in LA. It had tempered glass window panes, which Chasen said added protection from a burning car next door, and the occupants prepared well before evacuating.

One of the home’s main advantages over its neighbours was that it was brand new: the owner only moved in last year. “A lot of these houses in the neighbourhood were built from the 1920s through to the 1950s and were quite vulnerable to fire,” Chasen said. “No real protection was added to these homes when they were built.”

A car drives past homes and vehicles destroyed by the Palisades Fire.Credit: AP

Chasen, who grew up in the Palisades and lives in nearby Santa Monica, said Californians would need to have serious discussions about design and construction following these devastating fires, including the use of timber frames and mandating fireproof walls.

The issue has stirred debate on the letters page of the Los Angeles Times. “We are seeing what happens when we build homes with wood framing instead of tilt-up steel reinforced cement walls that would be more fire-resistant,” wrote Douglas Chapman of Santa Ana. Citizens were “too stupid” to insist on proper building codes, he wrote.

Dave Simon, a landscape architect from North Hollywood, said residents of fire-prone semi-urban areas could take all the design precautions possible, but damage would still be entirely predictable.

“Wood burns and steel melts and if you’re lucky enough to have a concrete home with a tile roof, even that type of structure will last only so long in an inferno,” Simon wrote in his letter to the editor. He also questioned why an insurance company would sell policies in such an area and why governments allowed vulnerable homes to be built.

Contrary to impressions of the US as a free-for-all country where anything goes, Molly Mowery, the executive director of the non-profit Community Wildfire Planning Centre, told this masthead fire-prone California had made significant efforts to enforce safer building.

“The state of California does have a very robust building code for wildfire,” she said. But it was only adopted in 2007. “One of the factors is that many of the [destroyed] homes likely pre-date current requirements for building codes. When you factor in housing stock, some of it I believe dated back to the ’20s, ’30s, ’40s.”

The measures in the 2007 code include requiring dual pane windows and for one of the panes to be made from tempered, or toughened, glass. It required render to pass a fire penetration test – though combustible siding and decking is still allowed – and generally compelled class-A fire rated roof coverings. There are also guidelines about where to put vegetation around the home and how to maintain it to reduce fire risk.

Even with these regulations, it’s easy for embers to ignite a home, said Stephen Quarles, an expert in the performance of buildings exposed to bushfire and an adviser emeritus to the University of California. Once the blaze jumped from bushland to the semi-urban environment, it could quickly become an urban fire.

Timber is used for the frames of most houses in the United States and Australia.Credit: Paul Rovere

“Once you have some limited number of ignitions within a neighbourhood, then you have this home-to-home scenario. Then the [building] materials make a lot of difference,” Quarles said. “Once you get inside a house, everybody’s going to have combustible things. They have wood floors, they have combustible furniture.”

More so than building materials, it’s ultimately the location of these properties on the foothills of the mountain ranges surrounding LA that make them susceptible to fire. Australia and California have similar debates about whether people should be allowed to build – or rebuild – in fire-prone areas (or flood zones). Climate change has made that discussion more urgent.

For example, firefighters spent much of the weekend aggressively defending homes in Mandeville Canyon, a leafy, narrow valley on the eastern edge of the Santa Monica Mountains that is popular with celebrities and accessible by just one dead-end road out of Brentwood.

“There has been a lot of development that has occurred over many decades with homes that were not always seen in fire-prone areas,” Mowery said. “Some homes and neighbourhoods just weren’t designed with fire in mind.”

Chasen, the architect, said the location of homes was another difficult and important question to grapple with, but he expected people to keep building in fire-prone areas, just with more resilient materials. “I don’t think there’s a way back, and knowing Americans, they’re gonna forge ahead. There’s no retreat.”

He also said the surviving Palisades home he designed showed wood-frame constructions could perform well against fire if done properly. In an earthquake-prone area, the alternatives of concrete and steel would greatly increase the cost of building.

“People I know who’ve done it in places like Malibu are really only very, very wealthy people who can afford to spend a multiple of what regular people spend on houses,” Chasen said.

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