The historic American Express Building is situated in the heart of Tribeca. This project includes a full interior renovation and residential conversion, a restoration of the original facade, and a two story 22,500 square-foot penthouse addition. Issues of visibility and a sensitive relationship to the existing building were paramount. In order to yield spatial dominance to this historic landmark, the addition consists of a playful arrangement of glass volumes that appear and disappear above the existing parapet. These volumes are derived from interior spaces whose proportions shift according to the domestic events they afford.