Located in the University City District of Philadelphia, Cira Green at Cira Centre South is the city’s first elevated park and part of developer Brandywine’s 2.7 million square foot mixed-use Cira Centre South neighborhood. Tucked between the Evo Tower and the FMC Towers, Cira Green is a 1.25-acre oasis perched 11-stories atop the parking garage, offering much needed open public green space with amazing views of the Philadelphia skyline and the Schuylkill Riverfront.
“We are very excited to introduce Cira Green, an elevated park that we believe will become one of the City’s most unique and celebrated public spaces,” stated Gerard H. Sweeney, President and Chief Executive Officer. “Our design mission in developing Cira Centre South has been to establish a new neighborhood lifestyle in one of the region’s fastest growing districts. Cira Green will perfectly complement the vibrant residential, retail and office environment that Cira Centre South presents to the marketplace.” – November 9, 2015 Brandywine Realty Trust Press Release
With slopes up to 20%, the Cira Green topography engages visitors; large portions of the roof deck are tilted, facilitating stunning views of the cityscape. The park’s shifting planes simultaneously generate a sense of protection and a desire to explore, but these intentional topographic lines also calm the otherwise aggressive winds, typical of most rooftop environments. The west side of Cira Green tilts upward, evoking a sheltered wall on the exposed roof. The center folds down to create a ramp to the existing 11th floor parking tier, revealing a covered support area that enables practical operational management of the event space. A terraced landscaped mound on the east side provides seating and more intimate spaces location for viewing the city skyline and the waterfront through clear glass guard rails.
Cira Green consists of different green roof areas, including large lawn areas, meadows, planters with trees, and colorful perennials. Many of these are native to the Mid-Atlantic and all three species of trees planted on the green roof are native to the region. Within the meadow zones, five of the seven species of grass are native to the region, and seven of the eleven perennial species are native to the region.
Designed by Roofmeadow, Cira Green has a unique water storage system beneath its sloping lawn, swaying meadows, and the pavers on the roof: Cira Green is Philadelphia’s first blue-green roof, which can route stormwater to the green roof areas.
Installed in the fall of 2015, the 52,000 square foot elevated park sits atop a parking garage that was originally designed with the structural capacity to accommodate additional floors. The garage was intended to be a semi-public facility with three floors of parking and a stormwater cistern below grade. As the design for the adjacent towers progressed, however, the stormwater management strategy evolved. Brandywine and its design team conceived of a dynamic elevated amenity space that could simultaneously comply with Philadelphia’s strict stormwater regulations. As the current Cira Green design vision unfolded, the cistern below the parking garage was repurposed to manage stormwater runoff from the Evo and FMC Towers. Additional floors were added to the garage to accommodate the parking needs of the nearby IRS offices.
The stormwater benefits of a conventional green roof are grounded in the ability of the planted roof to absorb and evapotranspire direct rainfall. Fully planted green roofs, however, generally cannot sustain active use and frequent foot traffic. Dynamic, lively, high-use gathering spaces are usually paved. Cira’s green roof concept interweaves both imperatives and re-imagines rooftop paving designs. The paved walkways and plaza space on Cira Green are designed as a blue roof: Thin detention cisterns, dubbed “pancake cisterns” by Roofmeadow, placed below the paving, capture rainfall and release it gradually to the adjacent planted areas via a system of Sutro weirs.