A public plaza is a community amenity that serves a variety of users including building tenants, visitors, and members of the public. This space type may function as pedestrian site arrival points, homes for public art, settings for recreation and relaxation, and inconspicuous security features for high profile buildings. Plazas are a beneficial feature of any lively streetscape.
Programmatically, plazas are strongly linked to the lobby space type. Both are a "public face" for a building that welcomes and orients visitors.
Flamingo is a large vermillion abstract sculpture in Federal Plaza in Chicago, Illinois, designed by Alexander Calder in 1974. Flamingo was the first sculpture to be unveiled under the Percent for Art program which administers a percentage of the city budget to public art.
Photo Credit: Carol M. Highsmith
The most important consideration in designing exterior plazas and public spaces is the expected, future, and potential uses of those spaces. Plazas should be designed to cater to a diverse set of activities including those that are active or passive, formal or informal, group or individually oriented, and planned or spontaneous. Plazas should invite users to partake in programmed activities (e.g. by providing seating, tables, and shade: lunchtime diners may be encouraged to frequent a space), but should also be flexible enough to accommodate activities that users plan themselves (a shaded, grassy area could host a performance, an impromptu game of Frisbee, or solitary reading). Typical features of plaza space types include the list of applicable design objectives 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.
- Access to Features: The design team must ensure that landscaping, level changes, or other architectural barriers do not prevent users from accessing amenities within a public plaza. This includes access to public art, water features, seating, and other fixed "furniture", like water fountains. See also WBDG Accessible—Provide Equal Access and Flexibility.
- Accessible Routes: Masonry and other hard surfaces must be designed with compliant slopes that meet ADA standards and properly direct rainwater. Local building codes as well as ADA standards will dictate the incorporation of ramps, elevators, railings, and other accessibility elements designed to accommodate wheelchairs, strollers, and other walkers using canes, etc. without compromising on aesthetics. Grass and earth covered plazas must be well maintained in order to ensure compliant routes and ground surfaces. See also WBDG Sustainable—Optimize Operational and Maintenance Practices.
All public areas of the 9/11 Memorial are accessible. The Memorial's name parapets are designed so that a seated person or a person of shorter stature has the same view as someone seeing the inner Memorial from a higher vantage point.
Photo Credit: PWP Landscape Architecture
- Materials: Utilize appropriate materials, furniture, signage, and art to reflect the public nature of the space as well as any required or intended image that the plaza must convey. See also WBDG Materials.
- Water Features: Water may be used as a visual and acoustic element. However, water features should not become a maintenance burden. In colder climates provisions must be made for easy shut-off and drainage during the winter season. The U.S. General Services Administration restricts fountains and reflecting pools with pumping systems to Category I areas of a site. Water features should not be placed over occupied space since leakage problems occur frequently. See also WBDG Sustainable—Protect and Conserve Water.
- Sculpture: In and around federal buildings, sculpture may be provided as part of the GSA's Art in Architecture Program. Under this program, art is not addressed by the site designer except as a coordination effort since the sculptor is selected under a separate contract. However, it is crucial in such cases for the artist and the A/E to coordinate not only the art installation, but how people will move to and from each other's designed areas and how one might support the other.
The renovation of Boston's City Hall Plaza will turn the seven-acre site into a welcoming, accessible space for all with civic spaces, play spaces, and updated public facilities. The plaza will also feature sustainability and resiliency strategies including an increase in permeable surfaces to soak up storm water, planning ahead for severe weather in downtown Boston. The design also includes 100 new trees, improving the shade, scale, and air quality of the plaza. Fifty lights will be replaced with efficient LED technology, and 22,500 feet of granite and brick paving will be reused or recycled.
Photo Credit: Sasaki
- Cost-Effective Maintenance: It is important to ensure that routine and preventative maintenance of landscape elements, water features, and artwork in plazas is planned for and can be performed at a reasonable cost in order to reduce maintenance costs as well as increase property value.
- Use Durable Materials: Materials for plaza spaces, amenities, and furniture should be very durable and resistant to the elements and vandalism. Metals that do not require repainting are recommended.
- Design Loads: Loads expected on the plaza must be considered in order to select the appropriate materials, waterproofing, and maintenance plans and practices. This includes the types and frequency of vehicles, number of pedestrians, furniture, and other loads including snow, water, equipment, and more.
- Encourage Flexibility: Plazas should be designed with electrical outlets lighting, and other simple infrastructure, to support future flexibility and encourage a wide range of uses. See also WBDG Functional/Operational—Ensure Appropriate Product/Systems Integration.
- Outdoor Furniture: Seating, tables, bollards, bicycle racks, cigarette urns, trash receptacles, flagpoles, lighting standards, and tree grates should be considered as part of the initial site design. Site furniture should be compatible in size, design, and color with the surrounding architecture and landscape design. Outdoor furniture is an essential element in creating useful and functional outdoor space.
- Seating: Seating is a public amenity that is appropriate to locate in the plaza areas of many federal buildings. Moveable seating can be an important component in effective public plazas. In many intensively-used public spaces, it is an effective supplement to built-in seating. Where appropriate, perimeter walls and stair elements should be designed to provide comfortable height and depth for seating. Seating should be designed and placed on the site to provide choices for employees and visitors. In addition, consider locating trash containers near seating areas and congregating points to encourage their use and to reduce litter and other environmental problems.
- Maintenance: The long-term upkeep and maintenance of landscape elements, lighting, fountains, and similar elements found in plazas must be considered during design and all other phases of the project. Equipment required for maintenance should be readily available and easily accessible, including standard equipment such as forklifts or electrical lifts.
- Programming Plazas: Consideration should be given to development of plazas and courtyards for employee and visitor uses, and for both planned and unplanned activities. It may also be possible to incorporate the building's program requirements into these spaces, for example, for use as outdoor dining or meeting spaces.
- Design Intent: The project team may need to consider preservation, restoration, rehabilitation, or renovation of an existing plaza, depending on its historical significance or status. The choice and requirements will affect the project scope, construction, uses, and costs.
- Respect for Historical Elements: Whenever possible, historical elements and materials should be reused, repurposed, and/or restored to promote the longevity of important community and cultural assets.
- Code Compliance: Quite often historic plazas do not meet current codes and standards, including for accessibility. So a careful analysis should be undertaken that balances the historic significance of the plaza while also bringing it up to current codes and standards.
The City of Collinsville, Oklahoma, undertook the renovation of City Plaza in historic downtown. The original brick that lined the old lot was removed and repurposed for the project. The renovated plaza features new lighting, several seating areas, upgraded landscaping, a platform for entertainment, and the City Plaza Archway. The City financed much of the project through Vision 2025 funds and other local grants.
Photo Credit: City of Collinsville
- Meet the Needs of Building Occupants: Well-designed plazas provide workers/occupants with a relief opportunity—such as breaks—from more confined spaces. See also WBDG Psychosocial Value of Space.
- Encourage a Variety of Activities: The design team should discuss with potential users how they would like to use the space, in order to incorporate appropriate amenities, relate outdoor areas to inside uses, accommodate traffic to and from the building, and provide for regular programmed use of the spaces and special events, as appropriate. Consideration should be given to different areas of a public plaza which would be appropriate for different types and intensities of public activities. With proper accommodations a plaza can bring the public in by supporting performing arts events and vendors. See also WBDG Functional/Operational—Account for Functional Needs.
- Bollards and Landscape Elements: To prevent vehicles from accidentally or intentionally entering a plaza from adjacent public streets, it is recommended that barriers be installed along the border of the plaza. These barriers can be simple bollards or fixed landscape elements. Stairs, statues, water features, or large planters can be enjoyable for plaza users and aesthetically pleasing while providing security for the building and its occupants. See also WBDG Landscape Architecture and the Site Security Design Process and Effective Site Security Design.
- Manholes: The placement of manholes in plazas and entry courts should be avoided, particularly along the main pedestrian routes and walkways.
Through the GSA's Design Excellence Program, the McCoy Federal Building in Jackson, Mississippi, addressed improved accessibility, sustainability, and a secured entry for twenty federal agencies. The re-envisioned plaza provides a landscaped oasis in the city for employees and visitors who utilize the building. The former concrete plaza is also part of a green landscape surrounding the project.
Photo Credit: Schwartz Silver Architects
- Site Planning: Entrance plazas should have slopes of 1 percent minimum and 5 percent maximum to allow for proper rainwater run-off. In areas with snowfall, provisions should be made for piling snow removed from roads or adjacent parking and drop off areas. See also WBDG Sustainable—Optimize Site Potential.
- Landscape Elements: Landscape and vegetation (especially native and adaptive plantings) should be considered, evaluated, and included on the plaza in order to help reduce heat island effect, clean the air, lower ambient temperature, reduce storm water runoff, provide places for wildlife, shade, and more.
- Storm Water Management: Where paved areas are adjacent to buildings, provide slopes of 2 percent minimum away from the structure to a curb line, inlet, or drainage way to provide positive drainage of surface water. Pervious pavers may be considered, but will be ADA compliant by using joints less than 1/2 inch wide. See also WBDG Low Impact Development Technologies.
- Water Conservation: Water consumption should be kept low, especially in very dry climates with high evaporation rates. Non-potable water sources may be considered for water features and landscape maintenance. See also WBDG Sustainable—Protect and Conserve Water.
- Bicycle Racks: Bicycle racks can be placed in plazas within a 200 feet walking distance of any functional entrance. This location should be highly visible by building occupants, security personnel, or by general traffic. Racks should have provisions for using bicycle locks and should be compatible with building and site design. Providing a secure and convenient place to store bicycles encourages their use. For the bicycle network and storage requirements for specific building types and LEED Rating systems see: USGBC LEED.
- Energy Conservation: Incorporate energy efficient light fixtures, signage, and other equipment on the plaza. See also WBDG Sustainable—Optimize Energy Use.
The University of San Francisco Center for Science includes a green roof and plaza which merge the indoor and outdoor spaces. The rooftop granite plaza features a native plant garden that provides valuable biodiversity habitat and filters rainwater.
Photo Credit: INTERSTICE Architects
Relevant Codes and Standards
The following agencies and organizations have developed codes and standards affecting the design of Plazas. Note that the codes and standards are minimum requirements. Architects, landscape architects, planners, engineers, and consultants should consider exceeding the minimum applicable requirements whenever possible.