Fire-resistant designs, community collaboration could be the best defense against future wildfires

Johns Hopkins structural design and resilience expert Thomas Gernay says fire-resistant building designs are key to protecting communities from increasingly destructive wildfires

The Eaton and Palisades fires recently destroyed or damaged more than 12,000 structures—including the iconic Malibu restaurant Moonshadows, the Palisades library, and the Palisades Charter High School—across Los Angeles County. Tens of thousands of residents have been displaced.

As firefighters continue to battle wildfires in the area, municipal leaders are starting to think about rebuilding efforts. Thomas Gernay, an assistant professor in the Department of Civil and Systems Engineering at Johns Hopkins University, has spent years studying fire-resistant buildings.

Here, Gernay offers insights into how California should approach rebuilding.

What are your observations of the California wildfires?

We examine these disasters to understand how we can change the built environment to prevent them from happening again. There are more than 10,000 structures that have been destroyed so, of course, there are immediate questions and economic policy aspects. But from the engineering perspective, it’s also, how are we going to rebuild? What kind of design decisions can we make on the built environment so that this kind of disaster does not happen again and in other communities?

Some aspects of these fires have to do with the layout of the communities or the interaction with the vegetation. California already had mandates, such as cleaning up vegetation around houses, but obviously they were not sufficient. Because there are such strong interactions between different structures, if one neighbor takes measures to harden their own house, it decreases the odds of an ignition for the surrounding houses. Inversely, if one homeowner does not implement proactive measures, it defeats the purpose for everyone.

What do engineers need to consider when designing buildings to prevent this?

Civil engineers need to think about how to harden structures so that they don’t catch fire in the first place. Sometimes we will lose a few structures, but we hope they don’t generate those embers that spread the fires. The choice of materials, for things such as roofing, decks, vents, and windows, will influence the chances that the house gets ignited and escalates the fires.

If you were to make a recommendation to the L.A. County government, what would it be?

We don’t have all the solutions, but I would recommend that we have to have a shift in thinking about these disasters. When conditions are extreme, such as they were in California, with wind and drought, it’s really hard to rely on fire suppression and suppressing emission. So there is a component of it that is about urban configuration. We need to think about what happens if a wildfire starts and gets into the community.

As we rebuild, we need to think about building materials, construction practices, layout of the communities, and more. Of course that’s upstream and not something that’s easy for the local government to do, but I don’t think it’s sufficient to work only on ignition suppression. There is work to do on the built environment, similar to what has been done for decades against earthquakes in California.

“As we rebuild, we need to think about building materials, construction practices, layout of the communities, and more.”

—Thomas Gernay, assistant professor of civil and systems engineering  

What technological advancements are helping architects design safer buildings?

We developed a software, called SAFIR, that simulates the response of the structural part of a building under fire. A user can input a fire scenario and the software will compute the temperature elevation in the structure, and then the deformation or collapse.

But some of this knowledge is not applicable to wildfires because what is important for wildfires is whether it will catch fire, more than the structural response. So some aspects of the software we are looking at are heat transfer, which is useful, but there are new, important developments that are needed if we want to look at how fires spread in communities.

With climate change increasing the frequency of events like this, how do you see this field evolving over the next 10-20 years?

I think a lot of advances will happen against wildfires. Traditionally, the field has been investigated by ecological science and forest management, but there is a blind spot in terms of how those fires spread in cities, so we don’t have models that are simulating how fires, such as in Palisades, spread. Those models would be very important during fires to support better evacuation, allocation of resources, and to prepare pre-fire.

If we have simulation capabilities for wildfires, we can study scenarios before they happen. You can take a city, such as Los Angeles, and say, “OK, what would happen if we have a fire that starts here?” Then, you can run it again if a community takes some of the protective measures, such as cleaning up the vegetation, making sure vents are closed, or changing construction materials.

In those scenarios the software can evaluate losses, damages, and people that are displaced. You can then evaluate the impact of different measures—not only for policymakers, but for insurance companies and more.

So there is research happening in that space, but we aren’t there yet. It requires complex physics. I think we will have great advances in those kinds of tools, and that will equip us better to mitigate against these wildfires as they are becoming more frequent and more destructive.