The Calhoun School, a progressive pre-K through 12th grade private school located on Manhattan's Upper West Side, commissioned FXCollaborative to design a four-story addition to the original five-story 1973 concrete and travertine building. The heart of the expanded school is a two-story performing arts center with a 234-seat black box theatre flanked by rehearsal spaces, a set design shop and music instructional spaces. Other new spaces include general purpose classrooms and science labs as well as a 5,200-square-foot gymnasium. The addition is topped with a green roof—a first for an educational facility in NYC.