Los Angeles fires are a sign of urban planning that is not adapted to climate change, according to an architect

While the long months of drought in 2024 and gusts of wind reaching up to 160 km/h are largely responsible for the scale of the disaster, the proliferation of housing in areas vulnerable to fires has only made the situation worse, believes Nicolas Michelin, who is involved in the ecological transition of architecture.

While he points out, among the immediate causes of the disaster, the need to bury the "extremely dilapidated" overhead power lines located near vegetation, to prevent fires from breaking out, Los Angeles is first and foremost, according to him, the archetype of a city "out of context".

"In the United States, as in Europe, we have built a lot of cities above ground, saying to ourselves +The site is beautiful, I'll put my house there, my building here+, but without taking into account the topography, the winds, the sunshine and the history of the site", comments Mr. Michelin, who advocates "custom-made" urban planning.

In Los Angeles, urban sprawl in the second largest city in the United States has both brought homes closer together, removing natural barriers to fire, and eaten away at hectares of high-risk areas.

Many homes affected by the flames, located on the hillside, were also inaccessible to fire and rescue services.

"We consider that the land is available, so we expand, and we build roads each time to get there, while it is the site that makes the project, and the project that makes the rules," adds Mr. Michelin, founder of the ANMA agency.

Even though the risk of major urban fires is not as high in France, he says there are "lessons to be learned" from what is happening in Los Angeles, since French local urban plans, which set the rules for land use and development, "are rarely tied to the nature of the sites."

"Urban prevention"

For a long time, in the United States as in Europe, architects have tended to design projects "which impose themselves on their environment", he recalls.

A legacy of Le Corbusier, a symbol of modernity today put to the test by the effects of global warming.

According to the United Nations Environment Programme (UNEP), the number of violent fires is expected to increase by 14% by 2030, 30% by 2050 and 50% by the end of the XNUMXst century.

The urban planning of "urban prevention" promoted by Nicolas Michelin applies to all natural risks, including floods. In Valencia, the scene of tragic floods at the end of October that left 231 dead, "we diverted the river so that it would not flood the city center, by putting asphalt everywhere and dams and we saw the result," he recalls.

In addition to urban planning, the type of architecture also raises questions. In the United States, the massive use of wood, used for 93% of new homes built in 2023, according to the National Association of Home Builders (NAHB), appears to be one of the aggravating factors of the Los Angeles fires.

"It's a real problem, but it doesn't call into question timber construction everywhere in the world, as we can encapsulate the wood with plaster or fibre cement panels to protect it from fire," stresses the architect-urban planner, who is not a fan of "concrete bunkers".

The risk arises less from the material used, than from "not building in the right place" such as "on the edge of a forest" or "in the middle of vegetation".

And if residential areas need to be densified, building to the maximum extent permitted by urban planning documents can also present risks.

"The owner wants to get a lot of money from the sale of his land and the developer wants to make the operation profitable, but we end up with projects that are once again out of touch, too big, too fat, too plump," observes Mr. Michelin.

"We need to reconnect with nature, build a little less, a little more densely, and accept in certain places not to build any more given the new climate situation," he concludes.