When local architects Erdy McHenry were asked to design Evo, a 34-story mixed-use tower on a narrow lot by the banks of the Schuylkill River, straddling University City and the Central Business District in Philadelphia, the commission from developer Brandywine Realty Trust came with an added assignment—to create a public gathering space atop the existing 11-tier parking structure adjacent to their vacant site.
Known as CiraGreen, the roof connects to resident amenity spaces in Evo, but is also accessible to the public from the ground level via dedicated elevators connected to the garage. (The garage itself had been designed to include several more levels that were never built, so it was able to support the green roof without additional structure.)
Though much of the 52,000-square-foot roof is planted, the paved walkways and plaza space are designed as a blue roof for enhanced stormwater retention. A 5-inch-thick cellular membrane beneath the pervious paving acts as a horizontal cistern, capturing rainfall and releasing it gradually to the planted portions, which include areas of soil up to 2½ feet deep for trees.
In a couple of spots, the grassy deck is lifted to provide inclined seating areas for viewing events, which have included musical performances and, more recently, film screenings. The larger of the two tilted areas rises 17 feet, offering views of the Philadelphia skyline just across the river and concealing public toilets and storage space beneath it.
CiraGreen has hosted numerous events and gatherings, from athletic boot camps and political fundraisers to a seasonal beer garden. It proves that, when you’re looking for a place to relax or party, the sky’s the limit.