The Neighborhood School and P.S. 63 share the historic McKinley School Building on East 3rd Street in downtown New York City. Both schools have collaborated to form the CITS Classroom in the Sky program with the ultimate goal of sharing a new integrated exterior learning space on the roof of the building.This proposal creates new access to the roof through two new enlarged stair bulkheads on the east and west sides of the central roof area. Students can come together on the roof deck that is shaded by wooden pergola structures on either end. The deck provides direct access and working space for various active planter zones, a weather station, rainwater collection system and a city-nature observation area.Surrounding the CITS deck is a reduced access modular green roof and solar panel array facing due south.