Respecting the Elements
Sustainable school landscapes are environments that are designed to respect the local climate, provide outdoor educational opportunities, and require reduced amounts of resources, including fertilizers, pesticides and water. Sustainable landscapes begin with an appropriate design that includes functional, cost-efficient, attractive, environmentally friendly and maintainable areas.
In 2007, the U.S. Green Building Council began certifying school projects under its Leadership in Environment and Energy Design (LEED) rating system. Whether or not a project is LEED-certified, important principles and design ideas can help achieve sustainability.
Installing a sustainable school landscape sets an example for students, and serves as a teaching tool for the school and community. Considering the importance of teaching the next generation about sustainability, education facilities from preschool through college are among the best places to experience and learn about sustainable landscapes.
They may be marginally more expensive in the beginning to install, depending on the amount of technology used and the choice of plants and other materials; ultimately, though, sustainable landscapes are more likely to thrive and can provide a school with additional educational opportunities, while saving money and manpower by reducing water use and maintenance requirements.
Sustainable opportunities
Whether the landscape represents new construction or is a renovation, consider preserving natural elements such as native trees and shrubs for shade, wind reduction and habitat protection. Riparian areas such as stream banks can be used as teaching tools for science classes. These areas can bring nature into the school setting, introducing wildlife such as birds, butterflies, bees and dragonflies. School and community gardens can be used to connect students with nature, help teach them about more healthful food choices and involve the community with the school.
Preserving the site’s topsoil and adding organic matter to the soil can help the landscape to thrive. Native and adapted trees, shrubs and perennials used around the building perimeter can soften and cool the exterior of buildings.
Sustainability goals can be furthered by using local materials that do not have to be shipped great distances. Shredded wood chips from local trees can help reduce the need for watering and weeding in planting beds. Native boulders can be used for informal seating areas and provide a sense of local aesthetics. On renovated sites, existing materials such as pavers and benches can be reused in the new landscape.
Green technology
The use of green technology can further sustainability. For example, at Casey Middle School in Boulder, Colo., the green roof received LEED credit for reducing the heat-island effect. The sedum and grasses on the roof absorb rainwater and act as insulators for the building, cooling the roof by reducing solar heat in summer. The rooftop planting design, a swirling pattern that mimics the plaza below, can be viewed through large windows in an upstairs common area. The plants and planting medium are contained in a series of large trays outfitted with a drip irrigation system.
As technology improves, some schools are beginning to use light-emitting diode (LED) lights in the landscape, which require less energy than conventional lighting. Photovoltaic panels that supply solar energy for the buildings also can supply shade beneath the panels. The extensive piping required for a school’s geothermal heating system can be installed beneath a sports field.
Synthetic turf for sports fields adds to sustainability by eliminating the water requirements of natural turf. Although it is composed of petroleum-based products, synthetic turf also uses recycled materials; old tires can be used to make up the resilient crumb rubber base for the turf. Synthetic turf also ultimately can help preserve the school operations budget by reducing maintenance costs because no mowing, water, fertilizers or repeated striping is needed, and the fields can be programmed more heavily for use by the school and community.
Easily accessible bike racks and safe bike lanes leading to schools encourage the use of non-motorized transportation and lessen the need for large parking lots.
Other considerations
Planning and designing a sustainable landscape provide excellent opportunities to educate administrators, facility managers, teachers, parents, students and other community members about these technologies, what it takes to install them, how to select native or adapted plants and local materials, and how to care for the completed landscape. Learning the differences between conventional and sustainable landscapes requires education during every phase and some special training, including training for both the faculty and maintenance staff.
Schools should ask the landscape architect to explain the site’s features, educational opportunities and maintenance needs to better use their sustainable landscapes.
The design principles are similar to conventional landscapes: Good design requires analyzing the site and how it interacts with the school buildings and surrounding community; knowing how administrators, teachers and students wish to use outdoor spaces; and designing zones for different uses, such as for active play or sports, socialization and outdoor learning. The circulation plan should take into account connections with sidewalks, streets, bike trails and campus paths to encourage walking and bike riding.
Wherever possible, reduce the amount of impermeable surfaces, or hardscape, which prevents stormwater from percolating into the ground and can lead to erosion and increased runoff. Where hardscape is needed for campus paths, roads and parking lots, consider using surfacing such as concrete or another lighter-colored material instead of asphalt, which is a significant heat collector.
Sustainable landscapes are zoned to conserve water and other natural resources. In a dry climate, xeric (or dry) native plant areas need water to become established, but subsequently require reduced supplemental watering; high-traffic sports areas regularly need watering to keep turf healthy. The most efficient irrigation system is automated and multi-zoned, with a "smart" controller that can be tied to a weather station, soil moisture sensor or a rain sensor on the site to tie local environmental conditions to the amount of water actually applied. Weather stations also can be used as an educational opportunity for students.
Bioretention areas, sometimes called rain gardens, are specially prepared vegetated bowls in the landscape, designed to collect stormwater runoff from roofs and other higher points on the site and temporarily retain the water until it infiltrates into the substrate. Bioretention areas and bioswales surrounding parking lots can be planted with water-tolerant plants in specially prepared soil, which will help filter and cleanse stormwater runoff containing motor oils, chemicals and fertilizers, while reducing the typical stormwater infrastructure.
Maintenance requirements can be significantly different from those for conventional landscapes. Properly selected plant material will require less ongoing maintenance. Native grasses and wildflowers do better if they are planted in areas removed from high foot traffic and are not mowed, but rather allowed to grow and reseed the area.
Henry, RLA, ASLA, is president of Design Concepts CLA, an award-winning community and landscape architecture firm in Lafayette, Colo., that has designed numerous LEED-certified and other sustainable school landscapes. She can be reached at [email protected].
