The Most Elusive Apartment in New York City May Soon Be for Sale

With 27 rooms over three floors, the maisonette at 660 Park Avenue is one of the most remarkable prewar apartments in all of New York. Designed for a Vanderbilt who never moved in, its monumental rooms were plucked from European manors and have somehow remained more or less unchanged for nearly a century.

For decades, we’ve had to be content with scant photos and a few descriptions hidden in decades-old newspaper articles to piece together what it actually looks like inside. But after its latest owner, Dame Jillian Sackler, widow to Arthur of the Sackler family, passed away at the end of May, it’s possible that the home will switch hands or be listed publicly for the first time in 44 years.

It all began, as with many major real-estate moves, with a divorce. In 1927, when Virginia Fair Vanderbilt finalized hers from William K. Vanderbilt II, she was living in the family’s Stanford White–designed mansion at 666 Fifth Avenue and needed a fresh start. Like heiress Marjorie Merriweather Post, who built a 54-room triplex penthouse atop 1107 Fifth Avenue to exacting standards, Virginia purchased the first three floors of 660 Park Avenue, a 14-story neoclassical building under construction by architecture firm York & Sawyer, to design a new home for herself. It would be a palatial maisonette, a type of ground-floor apartment that offered all the benefits of a fully staffed building with the privacy of a dedicated street entrance (a perk that appealed to some elite buyers). “Each floor is 60 by 100 feet, permitting 13 rooms to a floor,” reported the New York Times when it announced her maisonette in March 1927. “Mrs. Vanderbilt, however, is not going for numerical superiority. In her apartment there are 27 rooms, some of them duplex in character.”

Another feature would set it apart: While contained within 660 Park, the maisonette bore a custom address, 666 Park Avenue, perhaps a callback to Virginia’s mansion on Fifth. The maisonette was only recently assigned a new number: “660M.”

But Virginia would never set foot in her custom spread. Just a year later, she would sell “one of the finest apartments ever built in New York” to the president of National Distillers, Seton Porter. Ever polite, she did not say why, but the fact that her ex-husband and his new wife moved in across the street might’ve had something to do with it.

Porter oversaw the maisonette’s completion, sourcing paneling from European townhouses, castles, and country houses to bestow generational gravitas to this brand-new home. Burgeoning architect F. Burrall Hoffman, who had recently finished work on the Mediterranean Revival estate Villa Vizcaya for James Deering, was tapped to bring his fluency in period details to the project.

Porter’s grand project is now part of a small class of surviving prewar palaces. Designer and writer David Netto says the handful that remain include the triplex penthouse at 625 Park Avenue, the former home of Helena Rubinstein, and the John D. Rockefeller’s former 37-room duplex at 740 Park Avenue, now owned by Blackstone CEO Steve Schwarzman. So many others, from Marjorie’s 54-room mansion in the sky to Dr. Preston Pope Satterwhite’s 20-room apartment at 960 Fifth Avenue, were cut up into more manageably sized apartments over the years.

“There’s nothing else like it! The maisonette is more like a house than any other apartment in New York City, possibly ever,” says Netto, who recently published a book on one of the city’s most prominent prewar architects, Rosario Candela and the New York Apartment. “It’s the only real substitute for the great Gilded Age mansions that were demolished to make room for apartment buildings like these.”

The most impressive space in the maisonette is undoubtedly the approximately 50-foot-long, 24-foot-high drawing room with elaborate 18th-century pine paneling sourced from Spetisbury House in Dorset, England. The country house, built in 1740, was demolished, very conveniently, in 1927. The maisonette’s double-height library was finished in paneling sourced from a house in Grosvenor Square in London, and rooms upstairs feature painted woodwork and Louis XIII paneling from Château de Courcelles, a 17th-century château in Sarthe, France. “This might be the second-largest living room in New York City history,” says Netto. “Dr. Satterwhite’s living room at 960 Fifth Avenue, at nearly 60 by 30 feet, was the largest, but that apartment and living room were subdivided decades ago.”

While the maisonette’s monumental first-floor windows hint at the grand spaces within, its layout has remained more or less a mystery thanks to an impossible-to-locate floor plan and a tightly controlled front door. “There’s the whole building of 660 Park Avenue, and then there’s the maisonette. I’ve never even seen a light on in there!” says Netto. “I’ve been in that building many times to other apartments, and nobody has ever been inside the maisonette. Annette de la Renta on the sixth floor hasn’t even been inside!”

The architect and historian Andrew Alpern offered a description of the layout in his 1975 book New York’s Fabulous Luxury Apartments: “A flight of broad marble steps leads to a foyer whose walls are carved Caen stone. On this level is a double-height living room, a double-height dining room, and a double-height library, as well as a study, the kitchen, service pantries, and the servants’ hall. The second level includes separate men’s and ladies’ coatrooms and six servants’ rooms. The third level contains the master suite (bedroom, sitting room, dressing room, and bath) plus two other master bedrooms (each with its own bathroom) as well as a sewing room, extensive closet space, and five additional servants’ rooms.” Helpful, yes, but what’s missing is the scale of the rooms and how the spaces flow — or break — from one another.

Netto changed the game a few weeks ago when he posted the floor plan on Instagram. He agreed to tell me how he found the floor plan, but, in keeping with the maisonette’s mystique, only off the record.

It revealed some fascinating details about the maisonette’s construction. “Notice the vestibule between the dining room and living room,” says Netto. “These paneled rooms didn’t fit neatly into the apartment’s footprint, so this hallway helped to solve that issue,” he explains. “It’s a highly unusual layout for a New York apartment, generated by the notable paneling from a prominent country house.”

While the first floor is the most impressive, the second is perhaps most interesting. It’s not a full floor but a mezzanine with men’s and women’s cloakrooms and staff rooms. Netto explained the double-height rooms on the first floor extend so far upward that they consume much of the second floor, leaving room only in the back. This would function mostly as a service level, rarely seen by guests. “Upon entering at street level, you would ascend a flight of stairs to the main hall. At the moment of your arrival, a maid would take your coat to the second-floor cloakroom. You would not go there unless you maybe had to use the powder room.”

For such a large apartment, it has surprisingly few bedrooms. The third floor is home to the primary bedroom, sitting room, two additional bedroom suites, and the staff quarters. Like the palatial rooms downstairs, many of the bedrooms feature period paneling: 18th-century boiserie clads the primary, while beautifully painted rooms from Château de Courcelles — complete with their original fireplaces — are installed in an adjoining sitting room and bedroom. Rumor has it that a pretty glamorous Art Deco bath from the days of Seton Porter has also survived.

The maisonette last traded in 1981 when Arthur Sackler and his wife, Dame Jillian Sackler, purchased the maisonette from philanthropist Leslie Samuels, who had just lost his wife, Fan Fox Samuels. They were part of an exceedingly small club; the apartment has had just six owners over its hundred-year history. The one thing they’ve all had in common is a love and respect for the maisonette’s fabulous rooms and grandeur.

While the staff quarters have likely been renovated since the 1920s, the impressively paneled rooms have remained more or less unchanged. The last time we were treated to a view of it was in 2002, when Jillian opened its doors to Architectural Digest. She passed away on May 20 at the age of 84, and while it’s possible that one of her nieces, nephews, or cousins could inherit this apartment (she and Arthur Sackler did not have children of their own), it’s equally possible — if not probable — that the maisonette will soon be up for sale.

“This is a fascinating moment in the history of co-ops,” says Netto. “The $100 million apartments are now found in the soaring, glass curtain-wall buildings. Would anyone even want something like this?”

He has a point. When trophy apartments are now synonymous with supertall towers and sweeping views, a maisonette co-op may not be the first choice for those with the bank accounts and social connections to get by the board of 660 Park Avenue.

“I hope it is understood as a house, not as an apartment that’s on ‘too low’ a floor,” says Netto. “You can only otherwise find spaces on that scale in the grandest townhouses.”

Hopefully, the maisonette will self-select a new owner who feels just as much reverence for the interiors as the previous owners, especially since 660’s landmark protections  do not extend to the interior rooms. “Whoever comes next must have a respect for the English 18th-century decorative arts that the apartment contains,” says Netto.

Any proposed changes would also be subject to board approval, so perhaps at the very least, the notoriously picky 660 Park Avenue co-op board will be a steady steward of the maisonette’s principal rooms. “My earnest hope,” says Netto, “is that the paneling is never changed.”