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.)