A block from Grand Central Terminal, on the site of the old Brooks Brothers flagship, one of New York's most ambitious new office towers has just found a new partner from across the Pacific. SL Green, Manhattan's largest office landlord, has brought in Japan's Mori Building — the urban-landscape developer behind Tokyo's most transformative districts — as a partner on 346 Madison Avenue, the 46-story tower set to rise directly across from One Vanderbilt. Mori is taking a 49 percent stake in the project in a deal that values it at $175 million, while SL Green keeps majority control and steers development and leasing.
What the partnership is building toward is a roughly 850,000-square-foot tower designed to be among the most amenity-rich office buildings in the city. The all-electric design by architecture firm KPF — the same studio behind One Vanderbilt and One Madison Avenue — trades the typical center core for a side core, opening up column-free floors with ceilings stretching from 15 to 22 feet, nine levels with private terraces, and nine more wrapped in loggias and oversized glass.
The lifestyle pitch lives in a two-floor amenity collection, unusual even by current Manhattan standards. There's a 215-seat auditorium, a tenant lounge anchored by an épicerie from Michelin-starred chef Daniel Boulud — extending a culinary partnership with SL Green that already runs through Le Pavillon at One Vanderbilt and La Tête d'Or at One Madison — and a landscaped terrace overlooking Madison Avenue. A luxury wellness center brings a tenant-only fitness club, spa-quality locker rooms, and what the developers call the only regulation-size padel court inside an office building, with a world-class restaurant planned for the ground floor.
For Mori Building, the move deepens a relationship with SL Green that already includes a stake in One Vanderbilt next door, and it plants one of Japan's most influential developers at what SL Green chairman and CEO Marc Holliday calls the single best development site in midtown Manhattan. The corridor around it is in the middle of a transformation, with One Vanderbilt and the new JPMorgan Chase headquarters having reset the standard for the blocks west of Grand Central — and a wave of fresh Madison Avenue development following.
With demolition of the former Brooks Brothers building set for this fall and the tower targeted for completion in late 2031, 346 Madison enters the pipeline as a marker of where premium office demand is heading: toward fewer, finer, more thoughtfully designed addresses, in the one corner of Manhattan where tenants are still competing to be.