birddog

SL Green and Mori Building Launch 850K SF Office Tower at 346 Madison Avenue

SL Green and Mori Building Co. form a joint venture to develop a 850,000-square-foot office tower at 346 Madison Avenue in Midtown Manhattan.

By Colin Percy · May 27, 2026

SL Green Realty has entered a joint venture with Japanese developer Mori Building Company to construct a new 46-story, 850,000-square-foot office tower at 346 Madison Avenue. The project, located one block from Grand Central Terminal, is valued at $175 million. SL Green will retain a 51 percent interest in the development while serving as the project's lead developer and leasing manager, with Mori Building holding the remaining 49 percent stake.

Designed by KPF, the proposed building will feature a two-floor amenity center with a 215-seat auditorium, fitness center, tenant lounge, and an outdoor terrace, alongside ground-floor retail space anchored by a restaurant. This project marks Mori Building's first development venture in New York City. The site was previously acquired by SL Green from former Brooks Brothers owner Claudio del Vecchio for $160 million in September 2025.

Companies mentioned

architect

KPF

developer

SL Green Realty

owner

Mori Building

More news from New York

Get personalized project alerts in your inbox

Daily emails covering the projects and news that match your service area, building types, and the project stages you bid on.

Free now — first 50 founding members lock in 30% off at launch.

Free. One click to unsubscribe. No tracking pixels.