‘It’s a matter of when’: Roof design leaves suburban apartment buildings vulnerable to fire

Prospect Heights fire Chief Drew Smith experienced déjà vu when he arrived on the scene of an apartment fire Monday night that displaced about 100 residents in neighboring Mount Prospect.

“It was an almost identical layout to the fire we had in 2018 in Prospect Heights,” he said.

That fire at the River Trails Condominium complex destroyed 24 units and damaged 72 others, leaving dozens of residents without homes.

What linked those fires, and several other devastating apartment blazes in the suburbs since 2018, were the mansard-style roofs that sat atop the gutted structures.

The roofs were popular with builders in the 1960s and ’70s because they allow for additional living space on a building’s top floor.

But they present a daunting challenge to firefighters by shielding flames from water as a fire spreads.

“Unfortunately, the reality is that until the fire burns through the roof, the water can’t get on the fire. By that time, it’s just too late,” Smith said.

Similar fires ravaged the Windhaven condominiums in Palatine in 2023, leaving 22 units uninhabitable; the Puente Del Pueblo apartments in West Chicago, also last year, displacing about 100 residents; and the Bristol Court condominium complex in Park Ridge in 2022, injuring five residents and leaving an entire 36-unit building uninhabitable.

Last week’s fire at the Orion Parkview Apartments in Mount Prospect started in the cockloft, or small attic space, of the 36-unit building. The intense heat prevented firefighters from battling the blaze from the structure’s interior, forcing them instead to pour water on the building outside from aerial ladders.

Unlike the common areas beneath it, the attic did not have fire sprinklers. The mansard roof prevented firefighters’ water from reaching the flames as they rolled through the space like a bowling ball.

Mount Prospect fire Chief John Dolan said it is common for the roofs to have an 18- to 24-inch void space that runs the entire length of the building.

“They're basically a turtle shell on top of a building,” Dolan added. “If you're unable to attack a fire from the interior, you're forced to attack it from the outside. You can’t really get to the hidden fires.”

Smith’s familiarity with mansard-style roof fires has made him an expert on the subject, and for the past few years he’s been sharing his knowledge at the annual Fire Department Instructors Conference in Indianapolis.

“I do a presentation on it, and it's all about the construction of the roof,” he said.

Named after 17th century French architect Francois Mansart, the mansard roof first was popularized in the design of French homes. It is characterized by its distinctive sloping roofs, which are clad with decorative materials such as wood shakes and pierced by recessed window openings.

They fell out of style among U.S. builders after the 1970s, but many buildings with mansard roofs remain in the suburbs.

Smith wrote a report on a 2006 fire at River Trails, the same complex damaged in 2018, for the Fire Engineering website. It describes how fire and smoke can spread within the roof.

“During overhaul and the investigation, you could look into the mansard from the third floor inside corner apartment and see it run the length of the building without a fire stop” anywhere to be seen, he wrote.

The best solution, Smith said, is fire sprinklers. But it’s difficult and costly to install sprinklers in attics after construction is complete.

In the meantime, residents who lose their homes and belongings face devastating consequences.

“Their lives are changed. And those lives are going to be changed for a very long time if not forever,” Smith said. “Some of those people will have lost literally everything that they own.”

The good news is that when the buildings are rebuilt, they are generally built to meet current codes. But those who continue living under mansard roofs remain vulnerable to fire.

“It’s not a matter of if,” Smith said. “It’s a matter of when.”