This 1848 Gramercy Park townhouse renovation presented challenges for the architect (who is also the client). The building had been converted into a triplex crowned with three loft residences. But the architect wanted two dwellings, one atop the other, of equal value and scale. At the same time, the structure's deteriorating condition meant investing in a new steel frame, as well as the replacement of electrical, plumbing, and HVAC systems. By adding a penthouse, the architects got a 620-square-foot open plan house with a floor-through kitchen/dining/living space, media room, office, three bedrooms, and three and a half bathrooms.

Inside, the living room and kitchen ceilings are punctuated with sculptures by Emilio Garcia and exploding light fixtures by Ingo Maurer. The bricks-and-mortar rear wall has vanished, replaced by a glass curtain fitted with tiny diodes, invisible by day, but glinting at night. The outdoor terrace leading from the living room has a glass floor and overlooks the private gardens below. The house features two more terraces as well as a roof deck.