The Radian Apartments is a 14-story mixed-use student apartment community located in the heart of revitalized University City, adjacent to the University of Pennsylvania campus. Completed on September 26, 2008, its five green roof areas, totaling almost 15,000 sf, manage over one-third of the site’s stormwater and annually absorb approximately 194,218 gallons of water, which never enter Philadelphia’s overtaxed combined sewer system.
This project is a unique example of using green roofs to receive and treat the runoff from large adjacent un-greened rooftop areas. The main green roof, a four-inch thick 7,050 sf un-irrigated area established with pre-grown Sedum mats, serves as an amenity to the adjacent restaurant on the first story roof. The roof peaks in June, with Sedum rupestre, S. sexangulare, S. spurium, S. album, S. floriferum, and Dianthus blooming in pinks and yellow. In the fall as the weather cools, the green roof areas evidence rich reds, golden oranges, and yellows.