This project involved a complete renovation of a two story penthouse apartment located in a landmarked building on Park Avenue. The building was originally constructed in 1910. A penthouse conservatory was added next to a small existing penthouse. The small utilitarian stair to the existing penthouse was replaced with a curving oval-shaped stair that seamlessly ties the renovated lower floor, and the penthouse together with the new conservatory. The interiors are modernly classic with a formal presentation in color pallet and finish selection. Credits.