RICHBURG, S.C. — In densely built towns, wildfires can trigger a deadly domino effect, with flames leaping from home to home until an entire neighborhood is destroyed.
How does construction and landscaping contribute to this catastrophic chain reaction? Is there a better way to build? To find out, a rural South Carolina research center is creating giant wind storms and burning down houses — while gathering detailed data.
“We can watch failures here that you can’t watch out in the real world,” said Christina Gropp of the Insurance Institute for Business & Home Safety (IBHS) Research Center, a nonprofit funded by the insurance industry. Its scientists conduct studies to better understand building materials, designs and landscaping. It also hosts research by outside experts from UC Berkeley.
Its effort comes as wildfires are sending California’s insurance market into crisis. Grappling with escalating losses due to the magnitude and frequency of fires, many insurers are leaving the state. Homeowners are burdened with skyrocketing premiums — and some are losing coverage altogether.
There’s growing evidence that urban or suburban communities, not just remote mountain towns, are vulnerable to wind-driven fires, as evidenced by the destruction of Lahaina, Hawaii in 2023 and parts of Santa Rosa in 2017, say experts.
The Center’s work is influencing building codes, land use ordinances, architectural designs, retrofit applications and insurance coverage — changing how we construct and protect our homes.
Its experts make recommendations to state building code advisory committees and share research findings with consumers, builders, manufacturers, insurance companies, FEMA and the California Department of Insurance, among others, said Anne Cope, IBHS’s chief engineer.
“We need to better understand how to how to build our communities,” said UC Berkeley professor Michael Gollner of the Berkeley Fire Research Lab, who with professor Allen Goldstein is using the campus to conduct experiments about structure-to-structure spread and toxic emissions.
“Some protection measures work, and others don’t, so we figure out how to fix them,” Gollner said. “This ‘real world’ testing is expensive and hard — and desperately needed.”
The $40 million Center’s enormous wind tunnel — six stories tall — is the only place in the world that can conduct realistic wildfire ember storms to test the survival of full-scale one- and two-story buildings in a controlled, repeatable experiment. Embers, created by igniting wood chips in an underground chamber, are blown aloft by more than 100 powerful fans, each nearly six feet across.
Center scientists also can test the flammability of specific construction materials in an instrument called a cone calorimeter, which measures oxygen consumption, heat release rate, and smoke and toxic gas emissions.
In one $200,000 experiment, funded in part by California, it ignites a small home, decorated with a new sofa, chairs, tables, twin bed and modern kitchen appliances. High-tech sensors and other instruments record the fire’s temperature, flame velocity and more. As it burns, cameras document the threat to an adjacent home.
Hovering over the burning house, a UC-Berkeley drone collects smoke samples for analysis.
The Center can also mimic other natural disasters. In a realistic hail storm, cannons blast tiny ice balls — which vary in size and density, like real hail — at structures. Suspended water spigots recreate a fierce hurricane, dropping up to 8 inches of windblown rain every hour.
Out on its lawn, a “roof farm” of 96 different shingled panels is revealing the deterioration caused by severe weather, sun exposure and temperature fluctuations.
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Center scientists rushed off campus to investigate the deadly disasters in Paradise and Lahaina, picking through the rubble to better understand patterns of damage.
“We ask: ‘What was the first element of a house that got damaged? What was different about this, or that, building?’” said Faraz Hedayati, lead research engineer at the research center, who worked on investigations. “We can say: ‘This was the fire path. This is where it entered the house.’ We connect the dots.”
Its newest report. released this month, analyzed 170 burned homes in Lahaina. The report concluded that the density of homes and “connective fuels,” such as trees, secondary buildings, wooden fences and vehicles, contributed to the devastation.
Also important, according to the report, is the preparedness of homes located on the edge of a community. If constructed with fire-resistant materials and defensible space, these homes serve as the first line of defense, reducing the risk that the fire will spread to the larger community.
After each investigation, the scientists bring their observations back to the Center, where they can take a closer look at vulnerabilities.
Some of their discoveries have led to familiar recommendations, such as the elimination of all vegetation and wooden fencing within five feet of a home. Others are more novel. For new construction, they advocate the use of noncombustible siding and decks, simple roof and building shapes, enclosed eaves and metal reinforcement on vinyl frame windows.
“I’m optimistic that in the next 10 to 20 years, we’re going to have better building codes,” Hedayati said.
The Center also takes its research on the road.
At its most recent demonstration earlier this month at the Marin Fairground’s “Ember Stomp” in San Rafael, sponsored by Fire Safe Marin, residents gathered to watch drip torches set small spot fires — representing burning embers — in wood mulch around side-by-side structures. A conventionally built shed was quickly reduced to a pile of ashes. A fire-resistant shed withstood the flames.
California’s wildfire building code, passed in 2007, was designed to reduce a home’s risk of igniting.
In new homes, wood shake shingles aren’t allowed. Decks must be made of fire-resistant material, such as treated wood, tile or light concrete. Attic vents need to be covered in mesh to block embers. Homes must also have “defensible space,” limiting the amount of flammable vegetation immediately around them.
But these requirements are not as rigorous as the research center’s “Wildfire Prepared Home” designation program, where owners can have inspectors certify they completed a menu of retrofits and qualify for this special designation, and potentially a lower insurance bill. Of the roughly 4,900 California homeowners who have applied for this designation, about 800 are now certified.
Retrofitting can be expensive. While Insurance Commissioner Ricardo Lara in 2022 announced a requirement that insurers provide discounts to consumers for wildfire mitigations, homeowners complain that they’re not getting much, if any, credit for undertaking fixes.
In an era of climate change and severe weather, the Center’s research is revealing the weaknesses of existing building codes and products, said UC Berkeley’s Gollner.
“As scientists, we’re trying to get the knowledge out there to the decision-makers and public officials,” he said.
“It’s hard,” he said. “But there’s more and more push to do the right thing.”
