The headquarters for the Natural Resource Defense Council, a LEED Platinum-rated building, is an exemplary sustainable tower in the financial district of New York City. The building responds to a dense, mixed-use urban site that is frequented by residents, businesspeople, and tourists. With a double skin system that provides daylighting, natural ventilation, heating and cooling as well as rainwater collection, the building manages to successfully harness and integrate passive environmental systems in a highly restrictive environment. Active systems including solar and wind power help to operate the passive systems, making the building a living organism in and of itself. The structural system of the building responds to the form of the double skin. Entries toward Wall Street and Hanover Park provide key connections to the surroundings and a rotated core orients users toward the cardinal points. Public spaces include a theater, gallery, classrooms, café and gardens. Public vegetable gardens on the top floors provide a unique gardening experience and provide crops for a farmers’ market at Hanover Park in the spring, summer and fall. Office floors are grouped into four floors, the bottom of which includes shared conference and garden spaces to encourage resource-sharing between offices.