450 Warren sits where the brownstones of Boerum Hill meet the industrial scale of Gowanus. Tankhouse's first ground-up project, it rethinks the standard Brooklyn apartment building: in place of a double-loaded corridor, 18 homes are arranged as multiple volumes around three courtyards, with circulation pushed outdoors into walkways, stairs, and bridges. The arrangement gives most homes three exposures and few shared walls, and brings light, privacy, and outdoor space to a dense site.