Outside surface parking refers to large paved areas used for extensive vehicle parking—beyond the incidental parking provided for individuals, official government parking, and short-term drop off—located adjacent to a building. As defined for the WBDG, the Level of Service (LOS) of the outside Surface Parking is LOS A, indicating use by unfamiliar users, high daily turnover, and high percent of small cars and light trucks. This LOS prescribes 24'-0" (w) double flow aisles.
This parking is well maintained and is softened by green space, making it appear clean, safe, and accessible.
All parking structures—whether basement, structured, or surface—must provide for the safe and efficient passage of automobiles as well as visitors to and from their vehicles. Therefore, attention should be given to maximizing visibility for vehicles entering parking lanes and individual spaces, circulating within the parking lot, and entering and exiting the parking area. Typical features of outside surface parking space types include the list of applicable design objectives elements as outlined below. For a complete list and definitions of the design objectives within the context of whole building design, click on the titles below.
- Parking Spaces and Entrances: Accessible parking spaces must be provided for each parking lot associated with the building and calculated separately. At least one of every 6 accessible spaces, or fraction of 6, in each parking facility must be sized to accommodate vans. Accessible spaces must be dispersed among accessible entrances and be located on the shortest route to the entrances that they serve. (There are variations to the rules depending on the building type. See the U.S. Access Board for more information.)
- Finishes: Incorporate slip-resistant finishes to meet accessibility requirements.
- Signage: The international symbol of accessibility must be placed in front of the parking spaces mounted at least five feet above the ground, measured to the bottom of the sign. Van accessible spaces include the designation "van accessible".
Left: In some cases, achieving the shortest accessible route will require locating accessible spaces closest to an entrance ramp instead of the entrance doors. Right: Accessible parking sign that includes the International Symbol of Accessibility.
Images courtesy of the US Access Board.
- Visual Impact: The surface parking lot should not dominate the building site. Through a combination of planning, architectural, and landscaping elements, the visual impact on the surrounding streets and developments can be minimized or enhanced. For example, surface parking is generally located to the rear or side of the building and away from the street or street intersections, while providing direct pedestrian access to the buildings. Note that textures, patterns, and colors are encouraged in the design of surface parking in order to provide breaks in large monolithic areas of pavement and distinguish between pedestrian and vehicular movement within the parking area.
- Life Cycle Analysis: Incorporate materials, products, and systems that meet long-term life-cycle performance goals to reduce operations and maintenance costs.
- Maintenance: Care and maintenance of the parking lot should be part of the plan to keep the aesthetic value and prolong its service life.
- Plan for Additional Uses: Consider renting out unused parking spaces to nearby tenants to share costs and also generate additional revenue. Consider developing near mass transit if building a new lot or even renovating an existing lot to save costs and promote alternative forms of transportation.
Johnson Controls Incorporated (JCI) in Glendale, Wisconsin earned a LEED Platinum rating from the U.S. Green Building Council on four buildings—the largest number of buildings on one campus to achieve Platinum. JCI installed 285 energy-saving luminaires, which also contributes to lowering operating costs.
- Structural Requirements: Typically, surface parking consists of 6" slabs on grade, 4000 PSI, poured on top of a gravel base on compacted fill with a moisture barrier in between the gravel base and the slab. The slab is reinforced with welded wire fabric; the joints and wall junctures are sealed with sealant; and the surface is broom-finished. The light-colored concrete reflects the sun's heat and minimizes the urban heat island effect.
- Space Allocation: An average lot requires three to six times more square feet than the actual dimension of a car to accommodate drive aisles, ramps, and standard parking space dimensions. Land costs continue to rise, while the availability of space is becoming scarce. Consider incorporating lift technology or automated parking systems where land and space are at a premium. This can reduce the amount of needed square feet as well as save on construction costs and overall operating costs.
- Signage and Wayfinding: Signage should indicate all major internal pedestrian access points as well as external major roads and buildings. In surface parking lots, pavement markings are reflective paint and traffic control signage is usually reflective metal with minimum 5" high letters. The Manual on Uniform Traffic Control Devices for Streets and Highways (ANSI D 6.1e) provides guidance on pavement marking and signage.
- Parking Management: Curb-mounted parking booths with transaction windows and deal trays are installed at vehicular entrances/exits to manage entering and exiting vehicles. A cooling system, like a packaged terminal air conditioner (PTAC), is usually incorporated to supply the booth with outside air at a positive pressure relative to surrounding parking areas. Additionally, consider implementing electronic entry and exit machines, making it easier for users to self-park and pay. This is an excellent way to track garage traffic user patterns and manage money more effectively and safely.
- Exterior Security Protection: Surface parking is located such that unsecured parking areas are visible from adjacent buildings and safely illuminated. CCTV cameras and parking booths can provide added security by including site surveillance and limiting vehicular access control. See also WBDG Secure/Safe—Security for Building Occupants and Assets.
- Lighting: Lighting is used to provide security and access within the parking area at night. The lighting design should prevent off-site lighting and night sky pollution. Meeting or providing lower light levels and uniformity ratios than those recommended by the Illuminating Engineering Society are recommended. Strategies include: parking lot light fixtures that use fixture cutoffs and/or are optically controlled for light spillover and glare beyond the boundary of the development; and outdoor fixtures that are oriented and shielded to prevent direct illumination above the horizontal surface passing through the fixture. Outdoor lighting should be energy efficient, metal halide/high pressure sodium/or similar sources.
- Site Improvements: Typical site improvements directly related to the surface parking include ground cover and planting, storm water handling systems, vehicle parking surfaces and roadways, sidewalks directly abutting parking areas, lighting within the parking area, signage, and fences and screens around the parking and buffer zones between parking and public areas.
- Landscaping and Storm Water Management: Landscaping elements such as berms, walls, and indigenous hedges and trees are usually used to screen the periphery of the surface parking lot. Intermediate islands within the surface parking provide opportunities to plant native and/or adapted trees, which can provide shade in pedestrian walkways. Also, low impact development strategies, such as bioretention cells, should be incorporated into the surface parking design to maximize on-site infiltration of storm water. Modern storm water management systems often rely on vegetation to hold the soil, filter contaminants, absorb nutrients, intercept and transpire water, and support healthy and diverse soil biology. Select appropriate native plants for biofilters, bioswales, rain gardens, and other vegetated storm water management systems.
- Lighting: Incorporate energy efficient lighting and lighting controls into the parking areas, entrances, and exits to improve lighting levels while also reducing energy use.
- Parking Priorities: Plan for and provide priority parking for hybrid cars and electric vehicles (EV). Also provide EV charging stations to contribute to the adoption of EVs. Many cities are requiring buildings with parking to be EV ready, meaning that wiring and conduits are built into the lot, even if charging stations are not.
- Construction Materials: Use durable and sustainable materials with a reduced carbon footprint or that are locally procured and/or recyclable. Consider the material life cycle in the decision-making process in order to reduce the production and consumption of new materials.
- Permeable Paving: To reduce storm water runoff, incorporate permeable paving into the lot. Plan for proper maintenance of the paving as it requires annual cleaning and vacuuming of the surface. Permeable paving is also eligible for LEED® points under the sustainable sites, water efficiency, materials and resources, and innovative design credit categories.
- Photovoltaics: Incorporate solar panels whenever possible on the lot to support energy loads and provide shading.
Left: Native plants support the biofilters and rain gardens on this parking lot site. Right: The permeable pavers incorporated into this parking lot direct storm water runoff and pollutants below ground to reduce storm water treatment.
Dell Inc.'s headquarters in Round Rock, Texas made its parking lot more energy efficient, with the installation of a 130 KW package of solar trees. The new parking lot also consists of solar charging stations to provide charging points for electric and hybrid vehicles. The entire project also helps the headquarters run many of its operation via the solar power produced while reducing its greenhouse gas emissions.
The following diagram is representative of typical tenant plans.
Example Construction Criteria
For GSA, the unit costs for outdoor surface parking space types are based on the construction quality and design features in the following table . This information is based on GSA's benchmark interpretation and could be different for other owners.
Relevant Codes and Standards
Community Services, Educational Facilities, Federal Courthouse, Health Care Facilities, Libraries, Office Building, Parking Facilities, Research Facilities
Parking: Basement, Parking: Outside/Structured
Accessible, Aesthetics, Cost Effective, Functional / Operational—Account for Functional Needs, Secure / Safe—Security for Building Occupants and Assets, Sustainable—Optimize Site Potential