Sustainable Sites (SS)

Approaches under this category promote responsible, innovative, and practical site design and maintenance strategies that are sensitive to plants, wildlife, and water and air quality. Such environmentally sensitive site design practices reduce site operations and maintenance costs while creating outdoor spaces that are attractive and healthy for both building occupants and local flora and fauna.

Pavement Alternatives

Hard surface paving is a common part of most new or existing school facilities. Typically that has meant a non-pervious material, such as asphalt or concrete, is used ,which can sometimes cause water runoff, flooding, and water pollution issues. However, there is an alternative solution in the form of flexible, permeable paving systems. Some very attractive and appropriate systems use concrete pavers with open portions that can be filled with planted material, such as grass or ground covers or other material such as artificial turf or decomposed material. Either way, the intent is to allow water to readily drain into the ground to be naturally absorbed and filtered before making its way to other water resources, such as aquifers, lakes, streams, or rivers. The materials and systems available are fully capable of carrying pedestrian, bicycle, or vehicular traffic. At schools, that makes them ideal for fire lanes, parking lots, walking paths, swales, bicycle lanes, and other common hard surfaces on a school campus. As such, they function as durable, permeable hard surfaces providing versatility for a variety of locations.

Photo courtesy of Soil Retention Products, Inc.

Laguna Blanca School in Santa Barbara, California, used permeable concrete pavers to provide environmentally friendly parking around this K-12 school that addresses water runoff on-site.

CASE STUDY: POROUS PAVEMENT

The Los Angeles, California, office of CannonDesign worked with landscape architect WHITIN DESIGN WORKS of Laguna Beach, California, to incorporate permeable paving into a recent project in Anaheim, California. City officials mandated that a fire lane be included in the overall landscape design, but the design team wanted to be sure that something functional, purposeful, and sustainable would be created without losing the aesthetic of green space around the building. Michael Wilkes, a project manager and construction administrator at WHITIN DESIGN WORKS, noted, “In the 125-foot-by-600-foot space, we had to work with, we now had to also incorporate a fire lane. Our first challenge was how to site a fire lane that could work with our overall design. We also had to coordinate with local fire authorities and the building owner—we had to ensure that whatever we used, it had to be able to support a fire truck. We didn’t want it to look like a fire lane, and we certainly didn’t want to use solid concrete”.

After looking at a lot of product options, they settled on permeable concrete pavers that their firm had used for a project a few years earlier, and were extremely pleased with how the grass had grown over it and made it look like a solid lawn. For this application, the base layer was compacted to 95 percent. A filter fabric layer was then placed, and approximately 1.5 inches of growing medium was placed over the base. The growing medium was a 50 percent mix of organic matter and 50 percent sand. The earth was then rolled and leveled before the pavers were installed. The pavers were backfilled with soil and flush with other paving surfaces, then an additional half inch of soil was put over the pavers and raked and watered before immediately being hydro seeded. A long leaf fescue was used, and the growth has been uniform, creating a pristine looking lawn.

“The key to success with properly installing pavers like these is to prepare the soil, use a higher-quality soil for back fill, and avoid the use of too much sand,” says Wilkes. “I went back to the property a year later, and the lawn looked great! This project allowed us to create easy access to the building in case of an emergency without compromising our design. We are thrilled with the outcome and would recommend the use of permeable pavers for similar projects.”

Photo courtesy of Soil Retention Products, Inc.

Porous pavement can be exposed or designed to have a full covering of grass above it.

Outdoor Rooftop Spaces

Outdoor spaces don’t always need to be on the ground, rather, they can be located on borrowed spaces on rooftops, terraces, etc. Recognizing this, architects can create safe and secure areas for learning on rooftop decks. Such innovative spaces can be utilized for learning labs, gardening, science experiments, reading areas, and exercise. They can also help to maximize the useable space of the building footprint, particularly in urban areas where schools tend to be built up vertically rather than out horizontally. They can also provide some mitigation to the heat island effect by using plantings and other light-reflecting materials and surfaces.

The technical issue with creating such rooftop spaces is two-fold. First, the primary purpose of a roof is to maintain a waterproof barrier to weather, meaning that any roof deck system needs to avoid penetrations or damage to the roof. Ideally, it would actually help protect the roofing membrane and add to its longevity, while still allowing water to properly drain from the deck, onto the roof, and into the drainage system. The second issue is that even low-slope roofs are still sloped, and decks want to be level. Hence, an adjustable support system that can accommodate varying heights and create a level deck surface is needed.

The building industry has responded with complete systems for creating rooftop environments that are functional, environmentally appealing, and suitable for outdoor learning. Available products include adjustable pedestals that sit on top of the roof membrane and compensate for the roof slope and height change at the same time. The pedestals typically support a variety of different surface materials, including wood tiles that can be certified by the Forest Stewardship Council (FSC) for sustainability. Such tiles sit on the pedestals and provide a stable and natural surface for pedestrians to walk on and for other things, such as planters, benches, or gardens, to be placed upon.

Photos courtesy of Bison Innovative Products

Rooftop spaces can be used for outdoor learning environments when a system is selected that is specifically designed to work with the roof membrane, create a level surface, and meet all functional requirements for design and drainage.

CASE STUDY: ROOFTOP SPACES AT THE GIRLS’ SCHOOL OF AUSTIN

An excellent example of this approach being fully integrated into the design of a school is The Girls’ School of Austin, Texas, which was founded in 2002. This private school provides an intellectually challenging education for girls in a supportive and creative environment. The campus was constructed to accommodate the growing needs of the school with a 12,400-square-foot facility made up of a multi-purpose building, art and science classrooms, as well as multiple gardens and play areas throughout the campus. Of particular interest were the creation of outdoor learning spaces that offered an environmentally sensitive solution and the opportunity for environmental education. As such, the outdoor environment makes up from than 60 percent of the campus and includes well-designed, sustainable courtyards and rooftop decks. The rooftop deck, made with wood deck tiles and adjustable supports, has proven to provide a unique alternative educational space for outdoor learning.

Photos courtesy of Bison Innovative Products

Roof decks at The Girls’ School of Austin, Texas, provide outdoor learning spaces integrated into the campus.