More than 10,000 homes have been destroyed in Los Angeles, leaving only piles of charred wood and metal in the aftermath of fast-moving wildfires.

But amid the ruins, some houses still stood, seemingly untouched.

this is a phenomenon Also seen in other high-intensity firesit feels like good luck. Sometimes a house survives because the wind direction can change at the right moment. But more often, fire experts find these homeowners took key precautions that may have saved their homes from fires.

Key safeguards are those that can be put in place on the house itself and its surroundings, including the density of flammable vegetation. Many of these requirements are already required by building codes in California's fire-prone areas and their rules for clearing nearby brush and vegetation, known as creating "defensible space." several other western countries Similar standards are adopted, even among those who have experienced destructive wildfires.

In Los Angeles, fire experts are surveying surviving homes for clues in the hope of improving building standards and helping prevent similar disasters.

Building forensics

Steve Hawks is something of a forensic analyst. Not at the crime scene, but at the building.

In Pasadena, he was walking down a narrow dead-end street where several homes were destroyed in the Eaton Fire, which destroyed or damaged more than 7,000 structures. Hawks is here with a team from the Insurance Institute for Business and Home Security, a nonprofit research group that Studying how buildings burnfunded by the insurance industry. After major fires, the team was deployed to study how buildings perform in such extreme conditions.

He squinted at a building that had once been a detached garage, now a heap of black ruins with only fragments of walls still standing.

"Because of the winds that night that pushed the fire, I'm sure it was pretty high," he said, scanning the charred hills above.

But nearby, houses stood and appeared largely unscathed. It's the Eagles' job to try to figure out why.

#1 Clear vegetation adjacent to the house

Hawkes pulled up satellite images of the home before the fire, which showed the detached garage surrounded by greenery with plants clinging to the walls.

"So you can see the vegetation next to this garage, which likely contributed to the fire in this structure," he said.

Wildfires often spread through embers, which are tiny burning fragments that strong winds can carry up to a mile away. If embers land in bushes or trees, the fire can spread to new locations even if surrounding homes are not burning.

That's why Los Angeles has Rules that require defensible spacerequiring trees to be trimmed from the roof line and shrubs to be spaced apart. Homes in high-risk areas are inspected annually to ensure homeowners are complying with the regulations. The key is to make sure plants and shrubs don't touch each other and the house, like a highway of flames.

"If one bush or item catches fire, then we want it to burn out safely without igniting the next bush or the next bush and the next thing you know, the house is on fire," Hawkes said.

California is currently drafting rules Tighter restrictions on vegetation Right next to the wall of the house. Research shows that plants growing within five feet of a building significantly increase the risk of fire.

“The first five feet are critical,” Hawks said. "No combustible items within the first five feet of the wall."

#2 Leave space between buildings

When this detached garage burns, it can produce extreme radiant heat, with temperatures reaching thousands of degrees. This heat is enough to ignite nearby buildings. But in this case, the main house is 30 feet from the garage.

"Had this garage been closer, it could have resulted in the loss of this structure," Hawks said. "Our research shows that at ten feet or less, the distance is so close that when an object catches fire and burns, it's difficult for even good materials to withstand that much exposure."

An analysis by Hawks' team found that more than half of the homes in the Palisades fire-damaged areas with the most damage were less than 20 feet apart.

#3 Use fire-resistant building materials

Although the house survived, Hawkes discovered a burn mark on the exterior wall that appeared to have been caused by something catching fire next to the house. But the flames did not ignite the rest of the house because its exterior was covered in stucco rather than more flammable materials like wood.

The house's construction materials met many of the Eagles' other requirements. The roof is made of "Class A" fire-resistant materials, the gutters are made of metal, and the windows are made of double-glazed tempered glass, which is more resistant to shattering at high temperatures.

Even the smallest details matter. Hawks points to the attic vents below the roofline, which are covered with mesh. If the openings in the mesh are too large, embers can fly directly into the house and ignite it from the inside.

"So if you take a regular golf tee and try to puncture it through the mesh, if it punctures, it's too big," he said.

The surviving house is a newer one. Hawks said homeowners may have to build to comply with building codes in California wildfire areas (called "Chapter 7a"), which regulate many of these features. Research shows that for new buildings, Code doesn’t have to add a lot of cost. Older homes in the area often don't meet those codes, but Hawks said retrofits can still be done.

Hawks said every home that doesn't burn in an extreme wildfire is a benefit to the entire community because it doesn't generate heat and embers that could spread the fire elsewhere.

"We can't prevent fires in every community under every circumstance, so we need to prepare communities, and that's at the parcel level," Hawkes said.