Landscape architects and designers consider a number of factors when designing for outdoor spaces. These factors include both the social and physical criteria that can influence the use and function of the space. The Project for Public Spaces (PPS) has been studying and evaluating public spaces since its founding in 1975. The PPS has found that there are four key qualities that make successful public spaces.

“They are accessible; people are engaged in activities there; the space is comfortable and has a good image; and finally, it is a sociable place: one where people meet each other and take people when they come to visit.” ¹

In designing high-traffic outdoor spaces that are successful, architects, landscape architects, and designers should consider these four key qualities as outlined by the PPS: accessibility, aesthetic image, comfort, and sociability. Factors of safety, durability, and sustainability should also be considered.

Accessibility is achieved not only through location, visibility, and connectivity to and from other destinations but also through the selection of pavement surfaces that are safe for people of all ages and physical abilities. Compliance with the latest ADA (Americans with Disabilities Act) guidelines² is essential to providing outdoor spaces that are safe and accessible by all users.

An outdoor space with an appealing aesthetic image will naturally entice more users into the space. Appealing outdoor spaces appear comfortable, clean, have adequate lighting and seating, and provide quality design through material selection. In addition, outdoor spaces that are designed for flexibility and are able to accommodate varied user groups as well as serve a variety of outdoor functions are thus more appealing and experience heavier use.

Photo courtesy of Unilock

Public Plaza at the CN Tower, Toronto, Ontario, designed by IBI Group LA / Graham Infrastructure LP, provides an accessible, comfortable, sociable outdoor public space.

Materials that are modular can provide opportunities for changing the structure and function of an outdoor space. Varied pavement materials or pavement patterns provide tools for differentiating sub areas within a larger outdoor space. The broad range of pavement choices provides options for both design aesthetics and function.

An outdoor space that is comfortable has adequate site amenities such as benches and site lighting. Site lighting provides security and comfort during night-time use and it can help to identify a public space, defining and highlighting various activity areas, entrances, and important features.

PPS states: “In many situations, particularly when people are concerned about security, there is a tendency to over-light a park, plaza, street, or other public space. But in fact, too much lighting can be just as bad as too little lighting. The key to developing a good plan is to relate lighting to the evening functions of a particular space, because in the larger view, street lighting is more than just a technical requirement, a security need, or a design element. It can be thought of and utilized in terms of how the type, placement, and wattage affect how a street is perceived and used.”³

Benches provide comfort for users needing a place to stop and rest, enjoy lunch, take in a conversation or just to relax. Benches should be placed based on how the space will be used, not just in regularly spaced intervals along a walkway or within the space. Providing the correct type of bench or seating is also important. Benches should provide seating in a variety of sunlight situations, accommodate wheelchair users on either side of the bench, and be ergonomically designed for user comfort. Ergonomic design standards indicate comfortable seat height of 18 inches, seat width of 12 to 18 inches for benches with backs, and 30 inches for benches without backs and a 95- to 105-degree angle for the seat back.

Photo courtesy of Tournesol Siteworks

Thermally modified wood benches provide comfortable seating in high-use areas.

Social outdoor spaces attract people and “what attracts people most, it would appear, is other people” (William H. Whyte: The Social Life of Small Urban Spaces).⁴ William H. Whyte observed this pattern of attraction in public outdoor spaces throughout the world. People were attracted to outdoor spaces that had social gatherings of other people. And an outdoor space that presents an image of safety will be more likely to attract people. Such spaces are easily accessible, have adequate lighting for safe night-time use, have adequate visibility and adequate seating, and provide safe walking surfaces.

Durability of materials is an important design criteria for high-traffic spaces. Non-durable materials will wear more rapidly and will create unsafe and unsightly elements in the space. Non-durable materials will also increase client costs as they will require increased maintenance and/or more frequent replacement.