With the aim of carving out a generous amount of negative space in a city where breathing room is hard to come by, AvroKO kept the design of this three-story penthouse apartment in downtown Manhattan purposefully spare. A natural palette of materials (Belgian-oak floors, white-marble countertops) pairs soothingly with vintage furnishings in organic forms. The living room features 1950s Brazilian chairs and a biomorphic wood bench, while the dramatically sparse dining room holds only a rosewood table and eight George Nakashima chairs. A Massachusetts maker supplied the old-fashioned heavy window glass; the wide-plank floors in the bedroom were reclaimed from an Alabama gin factory.