As commuting patterns change, most office buildings will probably need less parking space. For office developers, that means the parking space they build now has to be flexible enough to become something else later.

Though commuting by car is still king, according to CBRE’s U.S. & Canadian Mobility 2018 report, that paradigm is on the verge of disruption. Ride-sharing, autonomous vehicles, upgraded public transit and even an attitude shift among millennials disinclined to drive will mean a decline in car use in major urban areas.

Designers are responding. For example, at the Cincinnati HQ of 84.51, a data analytics and marketing company, three floors of indoor parking were designed by Gensler to convert into office space in the future, Fast Company reports.

Likewise, at Hudson Pacific Properties' 275K SF 5091 Sunset Blvd. in Los Angeles — another Gensler design — two floors of parking can be converted into new office space as the need for parking declines, even in car-mad LA.

Overall, according to Gensler’s Peter Merwin, the two most important design strategies in making parking space easier to convert are flat plates and large floor-to-floor heights.

Any future use will require level ground rather than the steep slopes typical to garages, so designing flat floors on every level is critical, Merwin told Bisnow.

Also important in future-proofing a parking garage, Merwin said, is a 15-foot floor-to-floor height. That opens up the option to convert each floor into lofts, residential, retail or office.

"We’re finally at that point where we’re actually having a lot of developer clients who are questioning the financial feasibility of building parking garages,” Perkins+Will Senior Urban Designer Kristen Hall told Fast Company.

Building parking space that is hard to convert — a traditional garage with sloping floors and low ceilings — might not offer much in the way of long-term return. For future owners, such parking could evolve into wasted space as fewer people drive cars.

"Parking requires long-term planning and therefore the challenge for office owners, developers and city planners is balancing current demand with future uncertainty — both in mobility trends and office densities/flexible space," CBRE Americas Head of Office Research Andrea Cross said.