Funded by PECO, Temple University’s first green roof was constructed in 2005 atop the new Athletics Building on the Ambler Campus.The W-shaped 3,750-square-foot roof was inspired by the University’s mascot, an attacking owl. Two triangular-shaped “wings” pitch inward at an 8:12 slope toward the roof peak at the building center.
The roof is constructed with several layers and is an example of an extensive green roof. The first layer is a waterproof membrane that prevents leaks into the building below. The second layer is a root barrier membrane. Above it, a porous expanded polypropylene layer allows for rooting and drainage. The top layer is a two- to-four inch growing medium of heat-expanded shale mixed with heat-expanded clay and compost.
During the initial installation, one half of the roof was planted with a traditional cutting mat and the other half was planted with a variety of diverse species. The different planting designs were intended to allow for an examination of plant success on the roof. Some species included in the installation were Sedum, Delosperma, Jovibarba, Orostachys, Petrorhagia, Sempervivum, and Talinum.
In June 2008, faculty members in the Department of Landscape Architecture & Horticulture were asked to make the green roof more visible from the ground. At the time, Sedum spurium, Sedum floriferum, Sedum album, and Sedum sexangulare were the dominant species on the roof. To increase visibility, taller species such as Allium and Delosperma were planted in a six-foot wide area along the entire perimeter of the roof in October 2008. Additionally, a ground-based replica of the roof was constructed and installed adjacent to the Athletics Building in spring 2009. That fall, mats and additional substrate were installed in select locations along the perimeter to increase the area of vegetative coverage. Wayfinding signage was also designed and mounted to increase awareness of the roof location. In fall 2010, a time-lapse hourly video was created with a roof-mounted camera showing changes in vegetation over a one and half year time period.
More about the PECO green roof on the Ambler Campus and Arboretum and associated projects can be found in the following articles:
Kuper, Rob and Mike Olszewski. 2010. “Bringing down the roof.” Landscape Architect and Specifier News 26(7): 86-92.
Kuper, Rob. 2010. “The Tipping Point: How roof design and location affect Temple University’s pitched green roof.” Landscape Architecture 100(2): 50-61.
Kuper, Rob. 2009. “What’s Up: Examining green roof awareness in suburbia.” Journal of Soil and Water Conservation 64(5): 145A-149A.
Watershed: Wissahickon Creek
Temple University Ambler campus is located at 580 Meetinghouse Road in Upper Dublin Township and is home to the University’s Departments of Landscape Architecture and Horticulture, and Community and Regional Planning.
The green roof is atop the “Field House,” which is located off of Woods Drive near the baseball and softball fields. This facility provides equipment storage, offices, weight rooms, lockers and other amenities for Temple’s sports teams and their coaches.
Rose Creek, a tributary to Wissahickon Creek, flows through the landscape of the Ambler Campus.
$50,000 grant from PECO.
Plant Material ($1.04/sq.ft.) costs $4,160.00.
Roof Materials and Installation ($9.98/sq.ft.) cost $39,840.00.
Total cost is about $11/sq.ft. The market price for green roof installation is between $8 and $16.
Landscape Architecture and Horticulture Department