Green Roof Consultant: Roofmeadow
Property Owner: University of Pennsylvania
Architect/Landscape Architect: WEISS/MANFREDI
Civil Engineer: Stantec Consulting
General Contractor: Gilbane Building
Green Roof Construction/Maintenance: G.R.A.S.S.
Roofing: E.D.A. Construction Company
A Cross-Disciplinary Collaboration
The Meadow Roof is a prominent feature of the building, attracting individuals and groups eager to enjoy time on the rooftop amenity space. Surrounded by floor to ceiling etched glass walls on three sides and a clear glass railing open to the city on the fourth side, the Meadow Roof is also visually accessible from corridors and conference rooms. A second larger green roof includes native perennials and grasses planted alongside the building’s air handling and HVAC equipment. This larger sedum roof may is a storm water management workhorse.
Both green roof areas feature a diversity of planting that includes a number of native species that attract a variety of birds and pollinators. During the first year after planting, completion annuals (Gaillardia pulchella) germinated among the pre-grown Sedum mats. In the second growing season, the annuals emerged again, this time along with biennials and young perennials (Echinacea pallida).
Runoff water from the adjacent deck irrigates the Meadow Roof, which also is supplemented with a base-level capillary irrigation system during dry periods. The upper, non-greened roof runoff nourishes the two deep Meadow Roof bioretention tree pits, with supplemental irrigation during dry periods. The Sedum Roof manages the runoff from the adjacent rooftop HVAC equipment, the surrounding 15 foot parapet, and impervious paver walkways. The green roofs assure cost-effective compliance with Philadelphia’s Stormwater Regulations, reducing stormwater site fees by 27%. Additionally, integrating hydraulically independent biorentention cells into the extensive Meadow Roof obviated the need to replace the ground level detention basins with a more costly ground measure to both pre-treat and detain runoff.
Credit: Peg Woolsey