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An engineer spent 15 years fireproofing his California home. Here's why his house was the last one standing after a devastating blaze last year.

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This story is based on an episode of Business Insider Weekly. Watch the full episode here.

Devastating wildfires in California have burnt countless homes to the ground and displaced thousands of residents in the past few years.

Chris Arai is determined to not let that happen to him.

Arai, an electrical engineer from Healdsburg in Sonoma County, lives in an especially fire-prone area. When the Kincade blaze swept through his rural community in 2019, Arai's was the only house on his ridge that was left standing after the smoke cleared.

That's because 15 years earlier, back in 2004, Arai began dedicating himself to fireproofing his home. His painstaking fire-prevention techniques include a concrete basement he poured by hand, a fire-repellent gel he coats his windows with, and a sprinkler system that dampens surrounding vegetation to prevent fires from consuming them.

The Kincade Fire burned nearly 200 residential buildings to the ground — but not Arai's.

"Definitely the DIY aspect saved the house," he told Business Insider Today.

We visited Arai and saw firsthand the incredible lengths he went to fireproof his home.

The Kincade Fire ripped through Sonoma County, California, in 2019, destroying or damaging more than 400 buildings, including almost 200 homes.

Kincade Fire firefighter
Noah Berger / AP

Over the past few years, thousands of Californians have been displaced because of fires that are increasingly threatening and unpredictable.

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Austin Meyer for Business Insider Today

Chris Arai's home in Healdsburg was unaffected by the Kincade Fire. It was the only house on his ridge that was left standing when the smoke had cleared.

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Austin Meyer for Business Insider Today

Arai had dedicated himself to making his home able to withstand wildfires …

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Austin Meyer for Business Insider Today

… starting with the solar panels on top of his metal roof. The panels power his house as well as a sprinkler system surrounding his property.

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Austin Meyer for Business Insider Today

The solar-powered sprinkler system dampens vegetation as far as 45 feet around his house. "They can put a fair bit of water down out there that keeps those grasses, those lower fuels from catching," Arai said.

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Austin Meyer for Business Insider Today

Arai connected the sprinkler system to his pool and left it running after he evacuated. He estimated it pumped about 10,000 gallons of water before shutting off during the fire.

chris arai pool
Austin Meyer for Business Insider Weekly

The walls of Arai's house are made from a lime plaster that absorbs moisture.

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Austin Meyer for Business Insider Today

And when a fire is approaching, he smears his windows with this flame-repellent hydrogel.

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Austin Meyer for Business Insider Today

Downstairs, in the basement, the walls are made with with Durisol, a fire-resistant material. "It's filled with concrete and steel with insulation on the outside. So it's a foot thick," Arai said.

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Austin Meyer for Business Insider Today

These are the "massive" batteries that provide power for Arai's off-grid home. He hand-poured the concrete his basement floor is made of.

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Austin Meyer for Business Insider Today

Arai's efforts were put to the test in 2019 during the Kincade Fire. Video captured his house withstanding the blaze after he and his wife Tess had evacuated. "Tess asked me, are you sure that we're going to survive? And I said, well, I can't be 100% sure. I'm 95-plus."

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Courtesy Chris Arai

Amazingly, Arai came home to find his house still intact. "I get to the bottom of where our driveway actually starts, and I could see the corner of the building, and it was still in its original cover color, with what looked like a bit of roof on it," he said.

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Austin Meyer for Business Insider Today

Arai's safety measures earned praise from David Shew, a retired firefighter who now consults for the tech startup Zesty AI. The company uses AI to help insurance companies assess how at-risk properties are.

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Austin Meyer for Business Insider Today

"He did a lot of the right things — he had a lot of the boxes checked off," Shew said while watching a video of Arai's home. "It's really the attention to detail and then the ongoing maintenance for it as time goes on."

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Austin Meyer for Business Insider Today

But for Arai, making it through the fire was bittersweet, as many of his neighbors were forced to move when their homes were destroyed. "I'm happy to have survived it," Arai said. "But you know, I'm very unhappy that I lost all my neighbors."

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Austin Meyer for Business Insider Today

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Mark Abadi
Mark Abadi
Mark Abadi is the copy editor for Business Insider's award-winning video team. He previously was editor of Business Insider's freelance journalism. He has also reported on politics and breaking news.
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Daniel T. Allen
Daniel is a producer and host at Business Insider, creating videos that explore the limits of possibility in technology and the human body.He is a 2025 News Emmy Award winner for “The True Cost of Mining Electric Car Battery Metals” and helped to launch Authorized Account, an interview series that achieved BI’s highest average watch time. His work includes producing the most-watched video on the Insider News channel and developing World Wide Waste, a hit series about global garbage systems that generated more than 38 million hours of watch time and added 500,000 new subscribers by late 2024.