You have an office building where you really need a parking garage. What does it take to repurpose it?
IBC Load Requirements
Most other uses have a higher design live load than parking garages so the overall capacity of the existing framing is most likely capable of supporting the parking live load.
Parking Garage Floor Slopes
An office building’s existing floors are usually flat and don’t provide the desired drainage for a parking level so an additional topping slab, or additional framing on top of the existing slab, could create an appropriate drainage slope. The superimposed dead load from this topping or framing would need to be accounted for when checking the capacity of the existing slab. The additional thickness of the topping slab or framing would also decrease the headroom clearance within the building.
Concrete Corrosion Protection
The floors in office buildings most likely won’t include the corrosion protection measurements that would be recommended for a new parking garage. Measures should be taken to protect the existing framing from the moisture and chlorides that vehicles bring into parking structures. To protect the existing slab, a post-applied corrosion inhibitor or a traffic membrane could be applied.
Parking Garage Ramps
Another challenge with converting an existing office building into a parking garage is the need for ramps for vertical circulation. If an external source of vertical circulation isn’t an option, internal ramps will need to be introduced. This would require removing portions of the existing floor slab and creating new framing for a ramp from one floor to another. The removal of the existing floor diaphragm may trigger additional seismic upgrades to the structure.
Parking Garage Ventilation
Unless there are plans to remove the existing perimeter walls or introduce new openings, the new parking garage will most likely be classified as an enclosed parking structure due to the lack of natural air ventilation. An enclosed parking structure requires mechanical ventilation and sprinklered fire protection throughout the building that may or may not have been provided in the existing structure.
Parking is one of the most challenging markets to involve as either the existing or new structure in a repurposing project; however, it can be done. We’re seeing more and more repurposing in cities for a number of reasons in which we go into detail in this post.
Have a parking garage you want to repurpose as an office building? We have a post for that, too!