Above-Grade

Cost Factors

“Most striking about the design team was their flexibility and thoroughness. They were open to our detailing suggestions and responsive to the sequencing of construction in their design. ”
Steve Mitchell, Chief Operating Officer
Memorial Hospital Association

Above-Grade

How much do parking structures cost? This is one of the first questions clients ask. Before we can respond, we need to know the answers to the following questions:

  • How many spaces do you need?
  • How many levels?
  • What size is the site?

The answers have a major impact on the cost-per-space figure for a particular parking structure. Cost per space is dependent on two factors:

  1. Area per Space
  2. Cost per Square Foot

Area per Space

The area per space is affected by several factors, including the type of user, size of the site, shape of site, city parking requirements, and the type of flow system.

Type of User: Retail customer parking requires more generous parking dimensions than office employee parking, hence a higher area per space.

Size of Site: A narrow site may dictate a shallow angle of parking that results in a higher area per space than steeper angles or ninety-degree parking. A shorter site may require a speed ramp rather than a parking ramp, resulting in higher area per space.

Shape of Site: Irregular shapes create wasted areas within the parking structure.
Muncipal Parking Requirements: Some cities require wider spaces and aisles than others, no matter who the user is, resulting in a higher area per space.

Type of Flow: A level-floor structure with connecting express ramps will result in a higher area per space than one with sloping parking ramps.

Type of Structure: A two-bay structure with a double-helix configuration will have a lower area per space than a two-bay structure with an end-to-end loop configuration.

Two-Bay Double Helix
Two-Bay End to End


Cost per Square Foot

To calculate the cost per square foot, the following considerations must be weighed.

Geographical Location: Costs vary considerably by geographic region.

Number of Levels: Taller structures have a higher average cost per square foot because elevated levels are more costly than the ground level.

Shape of Site: The length of exterior facade per square foot of area is greater on small sites than on larger sites and greater on long, narrow sites than on square sites, resulting in higher costs.

Topography: Sloping sites usually result in expensive retaining walls.

Soil Conditions: Poor soil conditions result in higher foundation costs.

Exterior Architectural Treatment: High-level architectural treatments can increase costs significantly.