In Apartment 4E at 21 East 61st Street, prewar elegance meets 21st-century style.

Five-Star Living in a Reimagined Hotel on the Upper East Side

Grand Apartment 4E, at 21 East 61st Street, is our home of the day.

In New York City, it’s not enough to merely renovate a building of historic value; to get attention, such buildings must be wholly reimagined — while still preserving the things that made them worth reimagining in the first place. Such is The Carlton House, a glam former hotel on Madison Avenue in the Upper East Side, steps from Central Park (and Barneys, if such things matter to you). Artfully remade a few years back, the building — now 68 sumptuous residences — manages to feel state of the art while keeping its grand hotel aura. Sunny Apartment 4E embodies that balance quite perfectly. It’s our home of the day.

The Carlton House — the building has wisely hung onto its hotel name — is now in its third incarnation. Designed in 1940 as a 156-room residential hotel, it took a decade to finish, thanks to World War II. From there it became a Helmsley hotel, and, in 2010, it embarked on a meticulous transformation into the rarefied condo-op it is today, complete with a dazzling three-story addition (two stories of which were a 8,988-square-foot penthouse apartment), and a five-story, 9,742-square-foot limestone townhouse next door.

A 65-foot subterranean pool adorned with Indiana limestone is one of The Carlton House’s exquisite amenities.

The five-bedroom, five-and-a-half bedroom Apartment 4E is perched above an array of UES boutiques and restaurants (we’re unusually fond of La Goulue, right across Madison). In an elegant nod to an era that valued entertaining and a separation of public and private spaces, the 4,060-square-foot, nine-room residence features a large entry foyer and gallery, an expansive living room, and formal dining room facing Madison, and five bright bedrooms overlooking 61st Street.

Barneys New York, across 61st Street, provides Carlton House residents with a first-of-its-kind package of “bonus amenities,” including VIP access to the store and lunch and dinner delivery service from Freds, Barneys renowned ninth-floor restaurant and celebrity magnet.

Beyer Blinder Belle architects and Architectural Digest Top 100 interior designer Katherine Newman imbued common areas and residences with low-key luxury. There’s a 24-hour doorman and hotel-style concierge service available through Luxury Attaché. Down below, there’s a game room, a state-of-the-art fitness center with steam and treatment rooms, and the pièce de résistance: a 65-foot heated swimming pool trimmed in Indiana limestone, quartzite, and accents of glass mosaic tile.

Priced at $11.25 million, Apartment 4E, with an entrance at 21 East 61st Street, is represented by Corcoran agent Hilary Landis.