With the exception of the lower two floors and the penthouse, the building is divided by a central spine into one pair of two-bedroom apartments per floor. In contrast to the open-ended loft space at Perry Street, these apartments have been planned down to the smallest detail by the architect. The front part of each unit is organized around an island kitchen unit, which allows the living volume to flow into an adjacent study space that may also be used as a dining area. Both the bedrooms, each with a bath, open off the gallery running along the central spine. On the second floor, there are four apartments, two with a double-height living/dining room. As a consequence of this variation, the third-floor area is reduced, but this displacement leaves sufficient space for a pair of one-bedroom apartments facing north and south respectively, together with two studio apartments at the eastern end of the plan.

The elevations of the building have been thoughtfully designed to offer a stimulating contrast to the Perry Street development. While all three towers share a common architectural language, the Charles Street building is distinguished from its neighbors—whose facades are modulated by inset balconies—by the taught, smooth glass skin facing the Hudson River.