Cities are turning to repurposing existing buildings for a variety of reasons, and we discuss the ongoing trend in a post here. Parking is one of the most challenging markets to involve as either the existing or new structure in a repurposing project; however, it’s currently very popular to convert parking garages, or portions of parking garages, into office buildings. What challenges must be overcome to repurpose a parking garage as an office building?
IBC Load Requirements
The current International Building Code (IBC) specifies that parking garages be designed for a live load of 40 pounds per sq ft (psf). Some previous building codes specified as much as 50 psf so the actual capacity will be dependent on the year + location of the original project.
The IBC specifies that office buildings be designed for 65 psf (including partition loads). Therefore, structural reinforcements + modifications must be made for a parking structure to meet the code requirements for an office building.
Parking Garage Floor Slopes
A typical parking garage floor slopes 3/16” to a ¼” per ft for drainage purposes. Since most office tenants prefer flat floors, additional topping, foam insulation, or other type of framing would need to be placed on top of the existing floor to create the flat floor. This places additional load on the floor and affects headroom clearance.
Parking Garage Ramps
Similar to floor slopes, ramps don’t have much use in office building design. The ramp may need to be removed and rebuilt as a flat floor which can add significant cost to the project.
Overall, the existing framing would most likely need to be reinforced to account for the increased live load requirements, as well as additional superimposed dead load to create a flat floor in the structure. Converting an existing parking garage to a different use poses several significant challenges, and they can be overcome.
Have an office building you want to repurpose as a parking garage? We have a post on that, too!