Is it time to stop building in the wildfire affected areas of California?

Donald Trump’s inauguration as the 47th US president and his signing of a slew of controversial executive orders has switched the world’s attention from the devastating wildfires in California. The respite was only brief; on Wednesday, news broke of a new fire, Hughes, which at the time of writing had destroyed an area nearly three-quarters of the size of the second-largest fire, Eaton, which is still burning. The largest fire, the Palisades, is also still going.

These fires are the most costly in US history, with some estimates suggesting that the costs could exceed $250bn. A total of 63 square miles have so far been burnt, with 15,798 structures destroyed. The death toll currently stands at 28, less than the 85 who died in the 2018 Camp fire which destroyed the town of Paradise in California.

All the evidence suggests that the prime culprit is climate change. A phenomenon known as climate whiplash, where conditions swing wildly from one extreme to another, has exacerbated the risks. Heavy rainfall in 2023 and 2024 promoted the growth of grasses and bush, which dried out during last year’s severe drought.

This ready source of fuel, coupled with the fierce Santa Ana winds, which gust at up to 80mph, meant controlling these fires was a lost cause.

Now that the Eaton and Palisades fires are largely under control, should rebuilding start in these high-risk areas? Ultimately, halting carbon emissions must be the goal, but this is difficult and the cause has suffered a setback with Trump pulling out of the Paris climate accord on the first day of his presidency. Even if carbon emissions stopped tomorrow, it would take many decades for the climate to stabilise.

The reason why so much wealth is concentrated in the Palisades is thanks to sea views, cooling breezes, and the pleasant natural environment

So should the government ban construction in high-risk areas? California has a severe housing shortage, which is driving development in these areas. As safer land is built out, cities are expanding into the riskier, surrounding hills.

And people want to live in the hills. The reason why so much wealth is concentrated in the Palisades area is thanks to the sea views, cooling breezes  and the pleasant natural environment.

Measures to stop fires starting in the first place or slowing their spread would help. The Camp fire was sparked by an overhead power line failing in strong winds. The Pacific Gas and Electric Company was guilty of inadequate maintenance and went bankrupt thanks to liabilities of $30bn. Since coming out of bankruptcy, the utility company has implemented a programme to put overhead power lines underground in high-risk areas.

Cutting back dry undergrowth could help to check fire spread, particularly in calmer conditions, and residents could help by regularly clearing away leaves and pine needles in the vicinity of their homes. But short of cutting down all woodland and undergrowth, stopping all fires completely from taking hold is impossible given the extreme weather conditions.

In a fire, more resilient construction methods would make a difference. The standard form of residential construction is timber frame, or in some instances lightweight steel frame which is typically clad with timber boards. Some older roofs will be clad with timber shingles, although concrete and clay tiles are now used.

The problem with tiles is that wind-driven sparks can be blown under these and set light to vulnerable timber sheathing below. Once a fire has passed through an area, very little is left, typically just brick chimneys and twisted metal framing.

Brian Whitmore, the chief executive of California-based Studio W Architects, says government-funded projects that are built in Wildland Urban Interface (WUI) areas – places that are deemed a high fire risk – must conform to more rigorous building codes. These stipulate cementitious rather than timber cladding boards, non-flammable continuous roofing materials without gaps such as standing metal seam and other non-flammable materials such as brick and concrete. But there is no such requirement for these in private homes.

Various attempts have been made to introduce tougher building codes and brush management standards in high-risk areas – one such bill was passed by the Californian Senate and Assembly in 2020 but was subsequently vetoed by the governor Gavin Newsom on the grounds that this would restrict housing provision. Only last week Newsom signed an executive order suspending some environmental laws, building codes and planning permissions so that people can rebuild their homes more quickly. This does not bode well for future resilience.

The scale of these disasters is greater than the insurance industry can bear – or the premiums that most people can afford

Prohibitive fire insurance costs could turn out to be the great limiting factor. Whitmore has a house in a WUI area, a red flag to insurers. He says that he was quoted $25,000 (£20,300) for a standard annual fire policy. These costs have seen many people, including Whitmore, turn to a scheme called the California FAIR plan, a syndicated fire insurance pool run by all insurers; this was set up to provide basic fire insurance for high-risk properties with a cap on claims of $3m.

The scale of the recent devastation has led to concerns the FAIR plan could go bust under the weight of claims. In a bid to prevent high-risk areas becoming uninsurable,  California’s insurance commissioner Ricardo Lara recently announced a moratorium banning insurers from cancelling or refusing to renew the fire insurance of those living in the Palisades or Eaton or adjacent ZIP codes for one year.

Once the moratorium expires, residents will be forced to adopt better fire prevention measures and build using more fire-resistant materials, because the scale of these disasters is greater than the insurance industry can bear – or the premiums that most people can afford.

Otherwise, there is a real possibility that the only people who will continue to live in places like the Palisades are those who can afford to bear the cost of rebuilding their house themselves every time there is a fire. And, however rich they may be, no one really wants that.

Thomas Lane is group technical editor at Building