This story was originally published here in Inside Climate News.

As the smoke cleared and the ash began to settle from January’s devastating Los Angeles wildfires, an arresting image spread across news and social media channels: a gleaming white, three-story house, standing tall amongst the smoldering ashes of its neighbors along the Malibu beachfront.

Dubbed the “miracle mansion” and the “last house standing,” the home’s survival was attributed to the fireproof elements that its owner, former Waste Management CEO David Steiner, put into its $9 million construction. Steiner told the media that, along with the efforts of firefighters and a little luck, walls of reinforced concrete and a metal roof kept embers from igniting the structure, even as high winds pushed the Palisades Fire from home to home.

“Miracle homes” like Steiner’s have been spotted in the ashes of Lahaina, Hawaii, and Paradise, California, as explosive wildfires charged from forests and grasslands into urban areas in recent years. The conflagrations have been primed by changes in rainfall, temperature and wind patterns driven by climate change, overgrown vegetation and increasing development in fire-prone areas. They’ve led to calls from architects and politicians to build more fire-resistant homes and retrofit existing ones to be less vulnerable to the flames and embers that could ignite them, a process known as “home hardening.” Some of these, like covering vents, using fire-resistant cladding and clearing vegetation around homes, are low-cost, practical changes that are already required for new buildings in the most fire-prone areas.

But others, like building entire walls with noncombustible materials like concrete, are more burdensome, raising the question of whether building fortress-like homes and communities that can endure firestorms is feasible at the scale that will be necessary in California’s hotter future.

Some residents and housing advocates fear that more stringent building regulations could make construction costs unaffordable for homeowners, many of whom are already facing insurance payouts far below what’s needed to rebuild their houses. And experts who study wildfires emphasize that although homeowners can and should take some measures to make their homes less susceptible to fires, the real solution lies in fireproofing entire communities—a step that requires more money and planning than what’s on the table right now.

“We can’t solve the problem by individuals building out of noncombustible materials,” said Stephen Smith, who leads the Center for Building in North America, a nonprofit that advocates for housing reform. Instead, communities will have to rethink how they rebuild in the fire-prone wildland-urban interface, or WUI, something that’s difficult to do in sprawling areas like Los Angeles. “We’ve built ourselves into this problem,” Smith said.

Balancing Codes and Costs

Figuring out how to build more fire-resilient neighborhoods requires understanding why some homes survived in the first place. That’s what Yana Valachovic, a fire scientist at the University of California Cooperative Extension in Humboldt and Del Norte counties, set out to do when she arrived in Los Angeles County in January. As she had done after other urban firestorms in California, including the 2017 Tubbs Fire in Santa Rosa and the 2018 Camp Fire in Paradise, Valachovic studied elements like building materials and the vegetation surrounding the houses to determine why some structures survived the Palisades and Eaton fires in L.A.

Wildfires can burn homes through three pathways, Valachovic explained: direct exposure from flames that start to lick at the walls of the house, radiant heat from a house or vegetation burning nearby and—most crucially in wind-driven fires like those that broke out in Los Angeles—embers that enter the building through vents or lodge on flammable roofs. Installing metal mesh vents, clearing flammable debris from around the house to create what’s known as “defensible space” and using fire-resistant roofing and siding materials can all help reduce the risk of a home igniting.

Some regulations already encourage these changes. A California law requires buildings constructed after 2008 in particularly high-risk fire zones to build to more stringent codes, such as using ignition-resistant cladding and covering exterior vents. California governor Gavin Newsom is also advancing a law requiring homeowners in these zones to clear flammable objects from within 5 feet of their homes. But this policy had been stalled for years at the time of the fires in January due to delays in the rulemaking process as the Board of Forestry and Fire Protection searched for ways to defray costs of the new requirements.

In Pacific Palisades and Altadena, the two Los Angeles communities worst hit by the most recent fires, Valachovic didn’t see many of these upgrades, because the housing was made up of mostly older homes that aren’t required to be retrofitted. (The stricter California building codes only apply for new construction). Instead, the homes that did survive were largely saved by interventions from firefighters and homeowners during the fires, which can be dangerous and ineffective. Valachovic did notice a few homes built to the new construction standards that “performed exceedingly well” in places where firefighters weren’t able to respond.

“Some buildings defended themselves on their own,” Valachovic said. “That’s the sign of hope that mitigations do work.”

For communities that are rebuilding from scratch, one intervention is to use noncombustible building materials like metal and concrete from the get-go. These won’t eliminate the potential for a house to catch fire, but can reduce the odds, Valachovic said. Smith argued that these building methods are common in other parts of the world; in the U.S., where most homes are built out of wood frames, “the structures of buildings are inherently very combustible.” He said U.S. planners instead hope that spreading homes farther apart and defending them with sprinkler systems will offset that inherent vulnerability. But these defenses may not help during intense, wind-driven fires where embers lifted by the gusts can travel more than a mile and much of the water sprayed at structures is blown away before it reaches its target.

In those cases, the material the house is made out of can be less important than other interventions, like protecting vents and removing vegetation from around the house, said Michele Steinberg, director of the wildfire division at the National Fire Protection Association, a nonprofit that advocates for fire safety. She worries that states like California won’t adequately support these measures in the rush to rebuild in the wake of the fires.

“It’s disheartening to watch people not take in what they just experienced and think, this is going to happen again,” Steinberg said. “Why would you rebuild in any other way other than the safest way we know how?”

Cost is a major roadblock to rebuilding more fire-resilient homes. A 2022 report from Headwaters Economics and the Insurance Institute for Business & Home Safety found that building a house for “optimal wildfire resistance” in California would increase overall costs by between $18,200 to $27,100. While retrofitting a home can cost as little as $2,000 for basic upgrades to vents and decks, it runs as much as $100,000 for the most difficult changes, though those often aren’t necessary, the report noted. Some strategies, like clearing vegetation away from the house, can be done for free by homeowners.

Advocates like Smith fear enacting new laws that widen the areas that fall under the more stringent building codes or require retrofits of older buildings could impact housing affordability. “Making things stricter makes them more costly,” he said.

At the same time, the cost of these upgrades has to be weighed against the cost of doing nothing, and potentially losing one’s home in a future fire, Steinberg said.

Making these changes can also help reduce fire insurance premiums, decreasing the financial burden. But few funding opportunities exist to help homeowners shoulder the upfront costs, Steinberg said, although California has one program for low-income residents.

It Takes a Village

Adding to some homeowners’ hesitancy to invest in more expensive fire-resistant building materials is the problem that even the most hardened homes can be vulnerable if they’re the only ones in the community built to those standards, as intense radiant heat from a neighboring home that’s burning can ignite even fire-resistant structures. “You can build the perfect house, but if a neighbor doesn’t, you will still have risk,” Steinberg said.

Planning for wildfire resilience should take place on the community as well as the individual level, said Max Moritz, a wildfire specialist at the University of California, Santa Barbara. That requires thinking about how to lay out homes to make them more defensible in the path of an approaching wildfire, such as by adding buffer zones between heavily vegetated wildlands and housing developments, and building a road network that’s more conducive to evacuation.

These are difficult interventions, though, in places that have already been developed; neighborhoods like Pacific Palisades are unlikely to redo their entire road layout in the rush to rebuild. Adding to the problem is a lack of codes or standards for where to place a home on a parcel based on the topography and surrounding vegetation, Moritz said.

“How would you lay homes out in a neighborhood? Where would you build in the first place?” Moritz asked. “Those design standards don’t exist at those scales. And we need those. So when people build from scratch or when they rebuild, they have some guidance that is meaningful and will make for a safer outcome.”

So far, the standards that do exist are voluntary—the U.S. Fire Administration encourages some towns and developments to write Community Wildfire Protection Plans, while the NFPA runs a program to provide them with a risk assessment and makes recommendations for each area’s unique needs. More than 2,700 communities in 35 states were enrolled in the program, called Firewise USA, as of last year, Steinberg said.

These kinds of mitigation strategies can make a difference, Valachovic said. “Change is coming no matter what,” she said, and adopting reforms sooner rather than later will save costs as well as lives down the line. But the country’s haphazard approach to home hardening and wildfire-resilient construction makes her doubt its readiness for future fires.

“I haven’t seen a community in the American West that’s prepared,” Valachovic said. “There’s death traps everywhere.”