Research Site Simulates Extreme Weather To Test Building Materials After back-to-back hurricanes and wildfires, insurers are looking for more-resilient construction materials. That means building model homes and then blowing off their roofs or setting them on fire.

Step 1: Build A House. Step 2: Set It On Fire

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Last year's wildfires caused billions of dollars in damage. A lot of homes burned to the ground. But some buildings were more resilient than others. NPR's Rebecca Hersher recently visited a lab where the insurance industry studies what sets those homes apart by setting full-scale houses on fire.

REBECCA HERSHER, BYLINE: The lab is huge - a concrete cavern the size of an airplane hangar in a sparsely inhabited part of South Carolina. At one end is a wall of 105 fans.

ROY WRIGHT: Why don't I just take you up inside one of these fans?

HERSHER: Oh, sweet.

Roy Wright is the president of the Insurance Institute for Business and Home Safety, which runs this lab. The fans are inside tunnels, each big enough for a semitruck to drive into.

WRIGHT: This then channels all of the wind down so we can create winds well in excess of 140 miles an hour.

HERSHER: They play out all kinds of disasters here - hurricanes, tornadoes, hail storms. On the day that NPR photographer Ryan Kellman and I visited, researchers at the lab we're doing a full-scale fire test.

WRIGHT: So this is full of woodchips.

HERSHER: They're planning to shoot burning woodchips at an actual house to study different construction materials. The goal is to simulate what happens in real wildfires.

WRIGHT: Ninety percent of ignitions come not from a wall of flame coming but through those embers that pick up and fly.

HERSHER: Daniel Gorham is a fire engineer here. He's the guy responsible for burning down the test house.

DANIEL GORHAM: What we have here is a duplex structure. So it's a single building, but we essentially put a wall down the middle.

HERSHER: The two sides of the duplex are really different.

GORHAM: Which is what we're calling the wildfire-resistant side.

HERSHER: Tar shingle roof, metal gutters, gray siding that looks vaguely like wood.

GORHAM: You see the texture and the appearance looks like it's wood siding, but in reality, we can show you a sample. It's just fiber cement board.

HERSHER: The siding is made of cement, and landscaping around the house is also really important. On this side, it's off-white gravel around the edge of the house and some small bushes around five feet away. The other half of the house has mulch instead of gravel, bushes planted right up next to the house, vinyl gutters, actual cedar siding. It looks like a mountain cabin. Time to set it all on fire. We retreat inside behind a big window to watch as the fans start to turn and flaming woodchips fly out of metal tubes lofted on artificial wind and start battering the house. It only takes a couple minutes to see some action.

GORHAM: And we have some flame now. We have some flame now on the non-wildfire-resistant side in the mulch.

HERSHER: The flames go from the mulch to the plants to the siding, and in a few minutes, it's a flaming cabin. The windows break. The gutters melt.

UNIDENTIFIED PERSON: Fire is in the front wall of the building.

HERSHER: There's so much smoke, it's hard to tell what's happening on the other side of the house. It's not until the local fire department helps put out the flames, as planned, that it becomes clear.


WRIGHT: The side by side couldn't be more surreal. The duplex - one side fully engulfed and the other side - the other side's getting just as much embers, just as much pummeling it, and it is just going, I can take it.

HERSHER: The goal of tests like this is twofold. The researchers hope that knowing exactly how resilient different materials are to hazards like wildfires will help local governments update their building codes to withstand disasters better. And it's also about money. This lab is funded by the insurance industry. It was originally built after Hurricane Katrina; at the time, the most expensive storm ever recorded. But recent disasters have led insurers to invest even more in research, millions of dollars every year, to study ways to lessen the damage from increasingly frequent and severe storms and fires.

WRIGHT: If Harvey, Irma, Marie and the wildfires of 2017 made the case for resilience, Florence, Michael, the Woolsey and Camp Fires was an exclamation point.

HERSHER: Wright says the facility's budget has been growing steadily in recent years. Local insurance agents visit to learn about the resilience of roofing, siding, garage doors, carports and all manner of building materials. Wright says there is interest from across the country.

WRIGHT: We've hit an inflection point where we're seeing more events impact more Americans.

HERSHER: That's in part because climate change is affecting the whole U.S. and homeowners and insurers alike are looking for ways to adapt. Rebecca Hersher, NPR News, Richburg, S.C.

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