Rooftop patio with outdoor furniture, potted plants, a grill, glass windows, and a domed building in the background at sunset.

Chelsea Duplex Penthouse

with Iconic Cupola

Occupying a prominent corner within the landmarked O’Neill Building, Penthouse B is a premier duplex residence that balances Gilded Age scale with contemporary architectural precision. Originally constructed in 1887 as a premier department store in the Ladies' Mile historic district, the building was reimagined into a collection of luxury residences that retain the soaring volumes of its cast-iron heritage. This trophy home spans 4,819 square feet of interior space, complemented by a triple-terrace outdoor program totaling over 2,500 square feet.

THE RESIDENCE

The O’Neill

Building

The O’Neill Building is a full-service condominium offering a 24-hour doorman, concierge, and a 4,000-square-foot common roof deck with an outdoor kitchen. 

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Location Highlights

Located in the heart of Chelsea, the building provides immediate access to the West Village and Flatiron, as well as many of the city’s most established culinary and cultural destinations.

  • Lulla NYC

    Mido’s

    Semma

    Cafeteria

    Momoya Chelsea

  • Shy Shy

    Café Chelsea

    Gadfly Bar

    Jungle Bird

  • maman

    Sip Coffee & Matcha

    Somedays Bakery

  • Fairway Market of Chelsea

    Westside Market NYC

    Trader Joe's

    Whole Foods Market

  • Gym U NYC

    CompleteBody 19th Street

    Powerhouse Gym

    PureGym Chelsea

Exclusive Sales &

Marketing By

Logo for the Ocean Team, featuring a stylized letter 'O' resembling a wave or circle, with the words 'the ocean team' written beside it on a black background.
Bold text graphic displaying the words 'Sergeant Signature' in large white letters on a black background.

SERHANT. LLC is the first real estate company launched and designed for the marketplace of tomorrow. We grew from the #1 ranked sales team in New York City into a full-service firm that is revolutionizing the traditional real estate model. At SERHANT., we do things differently. Our in-house production and branding teams — SERHANT. Studios and ID Lab — develop disruptive content that engages the market by exploring new creative frontiers and redefining pathways to connect. Our tech-powered innovation platform, SERHANT. ADX, gives our listings unparalleled exposure by reaching more buyers than anyone else.

Our agents are driven to succeed, understanding of client needs, and trained to balance established sales strategies and techniques with innovative thinking. We understand that it’s more important than ever to help our clients and partners adapt to behavioral and market changes being driven by generational shifts and technological advances in society, and by combining traditional brokerage services with innovative production and marketing capabilities, we know how to do that better than anyone else.