Tag: Neighborhoods

But the new paradigm for fighting these fires contains an inconvenient truth. Most people don’t live in new houses, and most building codes aren’t as strict as California’s. And so, for the large majority of the approximately fifty million U.S. homes in the WUI, fire prevention falls to individual homeowners—it’s voluntary and ad hoc. “The approach that has been taken for the last quarter century has been one of, ‘Hey, something is better than nothing,’ ” Maranghides told me. “And, from a fire perspective, that is absolutely not true. Fire doesn’t work that way.” A homeowner could complete eighty per cent of fire-protection measures, potentially spending many tens of thousands of dollars on retrofits, and lose their house because of the twenty per cent that remains unfinished—in no small part because of uncontrollable, unpredictable embers.

This reality has led Maranghides to a position so logical that it reminded me of Spock, the ultra-rational character from “Star Trek.” For homes to survive fire disasters on their own, he said, people who live on the boundary with wildlands should not only clear sources of fuel from around their properties but also make a hundred per cent of potential home-hardening improvements. Even these extraordinary measures, he went on, are insufficient. No home is an island, and dense housing developments can protect themselves only if every neighbor does the same work. Such recommendations are so stringent that they may seem impossible; some of Maranghides’s colleagues in the fire-prevention world worry that the message will deter the public from trying. “You cannot pick and choose,” Maranghides told me. “The science tells us you have to do everything.”

For much of the twentieth century, forest fires tended to threaten rural communities. Over time, a particular approach to fire prevention emerged: if your house sat on a spacious parcel in or near the woods, you could work to protect it by creating a buffer around it. In the sixties, a California law supported by the state’s fire agency advanced the foundational concept of defensible space, a zone of up to a hundred feet where fuels such as brush and trees are strategically trimmed back and managed. The U.S. Forest Service eventually recommended the practice. But, throughout the decades, housing developments crept toward wildlands, the climate warmed, and fires increasingly escalated into unstoppable urban conflagrations. In the past decade, California’s most destructive fires incinerated more than fifty-seven thousand homes, commercial properties, and other structures. And, when the nearest source of fuel is not the woods but, rather, the house next door, a broader strategy is needed. Houses had to be hardened to make them less likely to go up in flames.

This past spring, I visited Maranghides at the National Fire Research Laboratory, which studies hardening strategies in a hulking, warehouse-like structure on NIST’s campus in Gaithersburg, Maryland. Enormous ventilation pipes were coiled like snakes on the roof of the building. Maranghides, bespectacled and in jeans, met me in the vestibule, where we grabbed white hard hats. From there, we entered a cavernous room with a reinforced concrete floor. A roughly fifty-square-foot air-exhaust hood—an industrial version of what one finds in home kitchens—hung from the ceiling.

A dozen researchers were gathered around a mockup of a single-story dwelling. A beige façade made from cement fibreboard featured a double-pane slider window, an asphalt-composite shingle roof, and a metal gutter. It was designed to be highly fire-resistant, in keeping with Chapter 7A and the International Wildland-Urban Interface Code. (The house was like a stage set, with scaffolding where the other three walls would have been; sensors tracked metrics such as temperature and heat flux.) But all eyes were focussed on a small shed made from corrugated steel sitting five feet from the house. Its open door, facing the dwelling, revealed stacks of wood inside.

“Stand by for ignition,” a voice announced through a loudspeaker. A man in firefighting gear approached the shed, used a propane torch to set a fire, and walked away. Within minutes, an incandescent blaze was shooting out the door toward the wall. We could hear loud crackling; embers flew about. Soon, orange-red flames began to lick the wall and the roof’s open eaves. Smoke spiralled upward. The window frame, which was made from white vinyl, started melting and then ignited. Around ten minutes into the experiment, the eaves were burning. A glass window pane fell to the ground.