What the 2025 Los Angeles wildfires revealed about urban design

Duke Dunham, AIA, LEED AP BD+C, is an architect, urban designer, and doctoral candidate in the Harvard Graduate School of Design. During an AIA26 session titled “Designing Buildings & Neighborhoods for Wildfire Resilience,” he helped attendees understand the features that make cities more vulnerable to wildfires—or more able to withstand them.

In January 2025, Dunham was in Los Angeles watching televised coverage of the fires in the Palisades. He found it surreal to see how the news portrayed what was happening. “They were saying that all of Los Angeles was burning,” Dunham says. But in reality, it wasn’t. 

From where he sat, the air was still, and there wasn’t even the smell of fire. Drawing on his background as an architect and urban designer, he had a realization: “There were two distinct areas that were in trouble. Watching the footage, I could actually see the embers moving in the fires. This wasn’t a wildfire; it was an urban conflagration. The embers were being spread by the wind—a direct response to the morphology or typology of the buildings.”

That realization set Dunham on a path to find a better way to address wildfires and how to rebuild afterward. Conventional wildfire protection wisdom says that homeowners should clear the perimeter and create a defensible space of about five feet around a home, design with fire-resistant landscaping, and install tempered windows, noncombustible siding, and a fire-resistant roof.

Dunham takes design ideas back a step further. “The spread of the 2025 wildfires in Los Angeles was directly a result of how these neighborhoods were designed.” He highlights factors such as whether the street and rear setbacks “had accessory structures, the width of the block, the kind of trees planted, and the uniformity of planting strategies.”

He believes that architects need to understand the effects of urban form, “which is never neutral when you're dealing with a wildfire. It always has [inherent consequences],” he says.

Research and analysis

To assess what happened during the Los Angeles wildfires, Dunham analyzed specific affected neighborhoods. For instance, he looked at the urban block patterns in the Pacific Palisades. Two neighborhoods there were originally designed by Frederick Law Olmsted: one affluent, one middle-class. Interestingly, he says, the middle-class area was among the few that survived.

He discovered that Olmsted had rotated the block 45 degrees to reduce grading costs, which aligned it against the Santa Ana winds, splitting the flames and diverting them away from the block. The smaller setbacks on the modest homes created a continuous block perimeter, diverting the fire and protecting the block.

In contrast, Dunham says, “the Alphabet Streets, designed by Abbot Kinney to maximize ocean views from the road, aligned perfectly with the prevailing winds—essentially forming flame tunnels flanked by rows of eucalyptus trees.”

Dunham also looked at the Via La Paz neighborhood. It featured a long promenade designed for a Methodist church at one end. The street’s angle created a slanted Venturi effect, accelerating airflow and creating a low-pressure zone that would shoot embers up the backside of adjacent blocks.

The lesson was clear: These fires weren’t random. Their behavior was dictated by urban geometry.

Designed to fail

As part of his research, Dunham used existing Lidar and OpenTopography elevation comparison data for 2015 and 2025, showing what physically remained after the fires. He then did his own research on computational wind analysis, he says, “to determine how the embers were actually traveling. Then I did a comparative analysis to understand how the fire behaved and how we could design better.”

Running the different fire scenarios helped him test “what if” options—for example, how the Palisades would have performed without any built structures. “Without the buildings, winds would have funneled more naturally through canyons,” he says, adding that “our urban density has actually created man-made flame corridors.”

Dunham believes that Los Angeles’ most vulnerable landscapes were unintentionally designed to fail under fire stress. The aforementioned traditional fire-protection measures only address symptoms; they don’t change the underlying morphology. Thirty years from now, the same neighborhoods are likely to burn again, Dunham says.

It will take a coordinated effort among architects, builders, planners, zoning regulators, and community leaders to rethink how parcels, setbacks, and blocks interact at a systemic level. Recognizing that every decision—from street orientation to block widths and vegetation patterns—either mitigates or amplifies risk is the first step toward designing resilient, responsive urban systems.

Stacey Freed is a freelance writer focusing on architecture and design. She lives in Western New York.