15 Union Sq W

A landmark boutique condominium conversion occupying a 12-story, 19th-century cast-iron building originally completed in 1870. The property contains roughly two dozen large, primarily two- and three-bedroom residences that blend preserved architectural elements—arched cast-iron window frames, high and double-height ceilings, and exposed structural bays—with contemporary glass and zinc façade interventions. Interiors commonly feature lofty ceiling heights, expansive arched windows, hardwood floors, formal galleries, chef-caliber kitchens with marble islands and premium appliances, generous walk-in closets, double vanities, soaking tubs and windowed wet rooms. Shared spaces are finished to a spa-like standard and include a full-length lap pool with oversized whirlpool, separate saunas, a massage/treatment room, dedicated yoga and boxing studios, a fitness center, and a game/recreation room. Full-service staffing provides 24-hour doorman coverage, concierge, valet and building porters, plus on-site mechanical and storage capacities and deeded/available private storage. Select residences offer private outdoor terraces or roof decks and in-unit laundry, Crestron/home automation, and substantial built-in storage. Located directly on Union Square, the building sits at the confluence of Flatiron, Greenwich Village and Gramercy, offering immediate access to parks, transit, markets, restaurants and downtown shopping.