The roof of the centrally located parking structure serves as an ideal location for recreational activities. This rooftop at the highpoint complex in Baltimore, MD now houses tennis courts. Providing oppenness on portions of the exterior can eliminate the need for adding provisions for sprinkers and ventilation (which tends to dramatically increase the cost of the structure). The precast concrete walls efficiently serve as fire separation from the stick built residential units that are constructed after the parking strucure.

While still not commonplace throughout the country, structured parking is making its mark on the multi-family housing sector. The trend is particularly pronounced along the east coast in larger metropolitan areas. The Consulting Engineers Group, Inc. has designed and detailed a significant number of parking structures servicing apartment complexes and condominiums, and felt the benefits of such a system would be of interest to many.

Although one might think that the decision of surface versus structured parking is as simple as comparing the cost of land devoted to surface parking to the cost of adding a parking structure, the analysis is not quite that simple. A common rule of thumb applied in this debate is that structured parking becomes economically viable when the cost of land approaches $30 per square foot. It seems simple enough, yet this rationale alone would rarely point a developer toward structured parking, so clearly there are other important factors at play.

One major contributing factor in deciding upon structured parking is that a sense of place is more easily established at the residential property. Too often the aesthetic appearance of an apartment complex is marred by the volume of surface parking located at its entrance and surrounding the building units. By locating a parking structure at the core of the apartment or condominium community, the need for surface parking can be virtually eliminated which greatly enhances the appearance of the property (see Highpointe entrance photo above) and provides more space for landscaping, recreational activities, and rentable space. Moving to structured parking gives an owner more flexibility in determining the development density which can be critical in phased construction that frequently progresses with market demand. Additionally, the reduction in surface parking can lessen the required provisions for stormwater run-off which helps offset the cost of the parking structure. Providing covered parking to all residents is easily achieved with structured parking and is a big selling point particularly in the Northeast. The rooftop of the structure becomes the ideal location for tennis and basketball courts that otherwise might be subject to use by neighborhood kids instead of residents.

Safety is another aspect of the development that can be greatly enhanced by structured parking. By pulling their patrons' most valuable and vulnerable possession (their car) into the core of the facility, which can be more closely monitored than the periphery of the property, developers are providing an additional level of safety that is hard to put a price on. A centralized parking facility equipped with controlled access can serve as the main point of entry for residents and their guests, and helps minimize the occurrence of unauthorized entry into common corridors. Once it becomes apparent that the cost of structured parking is feasible, the question then turns to the type of construction. This is where precast concrete really stands out as a building material. Since the parking structure is often times at the center of the site, erection starts prior to the beginning stages of framing the residential units and the structure is ready for the residents' vehicles weeks sooner than if cast-in-place construction was chosen. As always, the inherent fire resistance of precast concrete is of great benefit as well and precast walls frequently provide the fire separation between the parking and the apartments that is required by code. The photos included with this article are of the Highpointe parking structure that was a project designed and detailed by CEG for Structural Concrete Products (SCP).

CEG recently completed a parking structure for the Concord Park at Russett development near Laurel, MD, which is our fourth collaboration with Structural Concrete Products (SCP) of Richmond, VA involving a multi-family housing complex. The 7-story, 500 car structure at Russett serves approximately 330 apartment units. Each short end of this 2-bay structure consists of vertical shear walls with spandrel-column framing on the other two elevations. The apartments were set back from the structure and just enough openness was provided for the structure to be considered open, which eliminated the need for ventilation and sprinklers at the elevated levels. The significant change in grade elevation across the site was aptly accommodated using a short speed ramp toward one end of the structure which fit in well with the chosen locations for interfacing with the apartments. Precast design and detailing was completed in the fall and erection was completed in early February.

CEG's Texas office is currently working on four more parking structures for multi-family housing complexes. It is becoming clear that developers are beginning to recognize the benefits of precast parking structures and this segment of the parking market is sure to grow in the years to come.