Returning to New York City after many years away, the clients chose a gracious duplex apartment in a prewar building on Park Avenue as their new home, and they embraced the renovation as an opportunity to explore an urbane and sophisticated aesthetic. The wife, who has a sharp eye for design, was involved from start to finish, making this project a true collaboration. Having done residences for herself and her husband previously, she’d developed rules of thumb that guided everything from functional requirements to material preferences. Regardless of function, each room would be executed with the same degree of care.

French doors and wrought-iron balcony railings are a signature feature of the building and figure prominently in the main rooms. Doorknobs are custom copies of a favorite knob saved from a previous residence, while the art — whether a Motherwell drawing or an English equestrian painting — is carefully chosen to suit the architecture. The serene living room, fully paneled with a simple sticking detail and painted a pale lichen green, is complemented by a sisal rug and furniture that leans Scandinavian in style. Now paneled in pine with a soft white wax finish, the study has the unstudied comfort of an English country house library.

The kitchen’s floor-to-ceiling subway tile gives the space a vintage, utilitarian look that is elegant nonetheless, while the Shaker-style cabinets are fitted with wood knobs painted to match to avoid the contrast of metal hardware. That sense of restraint continues on the upper floor, where the primary bedroom and the main guest bedroom both feature working fireplaces with new stone mantels. After much trial and error, the team chose a luminous Calacatta marble for the bathrooms that has a hint of transparency. In a project that’s all about the details, it’s one more element that shares a through line of quiet elegance.

Interior Design: Suzanne Rheinstein