Wednesday, July 17, 2024

The quest to build wildfire resistant homes


“We have to get out of this idea that evacuating is actually always the best thing to do,” says Kolden. “We used to have community bomb shelters, right? These are functionally community fire shelters. Those are the kinds of conversations we haven’t had. And if we really want to build fire-resistant communities, We have to take them forward.”

The basic science of preventing a building from burning down isn’t particularly high-tech or expensive, but it’s the reverse of how we’ve long thought about wildfires. in the 1970s when jack cohen Pioneered the concept of “defensible space”, an area cleared of flammable vegetation or other fuel around a structure, has been largely ignored by the US Forest Service. It was a paradigm-shifting innovation—an easily implemented retrofit, at least wherever space was available—but it meant considering wildfires from a defensive position rather than an offensive one, which the Forest Service had fought for about 100 years. adopted for years.

Today the regulators have arrived, and California building standards for wooded areas with high and very high fire risk now require 100 feet of open space around structures, with at least 100 feet available to clear. Other house-hardening measures are comparatively smaller scale, even cheaper: replacing flammable roofs, caulking window seams and junctions, using fine wire mesh to cover vents where Spark can enter. And the latest fire-resistant materials won’t save a house where gutters have been allowed to fill with dry fire. Form follows function: flat roofs, steel windows, clean lines that leave no harbor for stray embers. Each devastating fire is bound to spur a new innovation as new vulnerabilities emerge.

The basic science of preventing a building from burning down isn’t particularly high-tech or expensive, but it’s the reverse of how we’ve long thought about wildfires.

California’s strictest fire code applies only to homes that are in a clearly designated high-risk zone (where, according to the California Department of Forestry and Fire Prevention, about one in four residential structures is located)—and only those. Applies to those that are newly made. In Paradise, where fires killed at least 85 people and destroyed more than 18,000 structures in 2018, about 40% were homes survived after 1996versus only 11% that were previously manufactured.

The incremental addition of more and denser housing in flammable dead-end valleys is a concern, says Thomas Cova, a clearance researcher and professor of geography at the University of Utah. The space between houses, or the lack thereof, is an important predictor of whether they will burn. Building suburban infill is in many ways good housing policy for a state suffering from a severe shortage of affordable housing, but it is poor land use policy for a state with frequent, intense wildfires. Nevertheless, there is little clear incentive for local authorities to prevent the construction of new homes, even those that would increase the risk to the whole community. Another flammable structure on the hill, one or two more cars on the road — but also revenue collected from another property tax bill.

Widespread retrofitting of the built environment in towns and cities established nearly a century ago is essentially off the table—it’s work that isn’t required under state code, and no obvious funding sources are available. Even where communities are wiped out by fire, existing roads are not covered by minimum fire regulations when it comes time to rebuild. But completely new housing tracts are held to very high standards.

“I’ve always thought of shelter-in-place as a backup plan in case of emergency, and it would be really wise to consider what options you might have,” Cova says. “But now, I think it’s also entering into discussions related to [new] Development.”

This is especially true in light of California’s acute housing affordability crisis, which has put the state under severe pressure not only to continue building new homes but also to build them on cheaper, more rural, more fire-risk land. Have given. New one Guidance issued in October 2022 Local agencies have been explicitly told by the Attorney General of the State of California to “avoid over-reliance on community evacuation plans” and to consider shelter-in-place options.