It’s a visual that seems to defy the laws of physics.
Four wind turbines blow fire at two seemingly identical structures. One of the structures quickly starts to burn. A few minutes later, it’s nothing but a shell. But the other one doesn’t catch fire and comes out almost entirely unscathed.
This comes from a demonstration by the Insurance Institute for Business and Home Safety (IBHS) — a research nonprofit supported by home insurers — that shows how fire-resistant materials and landscaping can protect homes in cities prone to wildfires.
This issue is top of mind because of the wildfires that continue to devastate Los Angeles. While the number of homes that have been destroyed is fluid, at least 15,000 have burned. When the focus turns to rebuilding, it will require difficult conversations about not only building materials, but zoning laws, building codes, home insurance premiums, the local economy and the trade-offs between them.
“There are questions there about how you balance the need and desire to rebuild really fast with hopefully building in a way that’s a little bit less vulnerable to future wildfires,” said Andrew Rumbach, a researcher at the Urban Institute. “And we need to do that in a way that doesn’t have unintended consequences that really make some people worse off.”
Building a home with resilience in mind starts with making the roof with non-combustible materials like concrete, clay and metal. Walls need to be made of things like concrete, brick and stucco. The bottom six inches of the walls are particularly vulnerable because embers tend to collect there.
IBHS recommends a finer mesh for anything that provides ventilation to keep embers from getting into the house. Fencing, which tends to be made of wood, needs to be replaced or removed.
But possibly the most important way to protect a home is by building a “defensible space” around it that removes anything within five feet. This way, there isn’t anything especially flammable touching the house or close enough that a bit of wind would cause it to catch fire.
“When embers hit your home, they circulate in almost a rotor vortex that sets up in your home in these high wind events that come with wildfires,” said Ian Giammanco, a managing director at IBHS. “So, whatever is in that [five-foot] zone will accumulate embers. If embers are accumulating against something combustible, it’s going to ignite it. You now subject your home to flames and radiant heat, not just embers, and even some of the best [building] materials can reach their limit.”
One way they can reach their limit is if fire-resistant homes are surrounded by those that aren’t resistant and easily catch fire. The California Building Industry Association (CBIA) — a trade group for homebuilders in the state — advocates for addressing resilience at scale by building entire communities with resilience in mind, as opposed to single homes.
This requires developments to be placed around things that don’t burn as quickly or fiercely as wilderness or typical landscaping. The group recommends surrounding homes with things like citrus orchards, avocado orchards, succulents or even golf courses.
But homeowners tend to rebuild on their own terms. Thus, there isn’t a group of them taking a holistic approach to fire resilience, which limits the effectiveness of rebuilding in areas that have been destroyed.
“There’s not usually a master-planned approach to a burnout area because it’s the individual homeowner with her individual insurance coverage to determine certain individual decisions,” CBIA president and CEO Dan Dunmoyer said. “So, it’s not a communitywide effort. They’re not opposed to helping with that, but generally it just doesn’t happen.”
Building with resilience at both the individual and community levels requires the interests of stakeholders to align. When it comes to those of homebuilders and insurance companies, they generally do.
Home insurance companies have been steadily pulling out of parts of California and Florida because climate change has increased both the frequency and intensity of severe weather events. Essentially, it no longer makes business sense for them to renew policies or issue new ones.
Insurers often take heavy hits due to catastrophic natural disasters. A recent estimate from CoreLogic pegged losses related to the current LA wildfires as high as $45 billion.
While homebuilders may not have much experience with resiliency measures, homeowners may create enough demand for them to prompt more early adopters. Where a builder might object is with the defensible space allotted, since it would effectively reduce the size of the house.
Having experienced the worst of a wildfire, many homeowners looking to rebuild will want these measures in place, even if it costs a little more to do so. But Dunmoyer said these costs aren’t so high that they’re prohibitive, particularly compared to home prices in LA.
The municipal and state levels are potential roadblocks. The easiest way to achieve fire resilience at scale is through regulation and building codes. As with other issues, there will inevitably be pushback from homeowners, particularly in situations where they would have to retrofit their home with fire-resistant materials and precautions.
Elected officials also will feel the pressure to rebuild as quickly as possible to get the local economy going again, but that can come at the expense of taking the time to plan the best course of action. This is particularly true in areas like Altadena where homes and infrastructure can be as old as 100 years. And that’s to say nothing of zoning changes, which are always a political battle.
But given how devastating the LA fires have been, there’s a chance that political will and homeowner demand could push things toward a safer setup.