SL Green’s 27-Story Office & Retail Expansion in Flatiron Nearly Finished

The installation of the exterior facade is nearly finished at One Madison Avenue, a 27-story commercial building located in the Flatiron District. 

What we know about the development: This project is a collaboration between developer SL Green, the National Pension Service of Korea, and Hines. The design is being handled by Kohn Pedersen Fox. It involves a comprehensive update of an eight-story structure and the addition of a 19-story structure over the current roof parapet. The development is expected to span a total of 1.4 million square feet of office space and ground-floor retail. NYC Constructors is overseeing the expansion construction, while AECOM Tishman is serving as the construction manager for the property. Situated at the southeast corner of Madison Square Park, the building spans a full city block between Madison Avenue, Park Avenue South, East 23rd Street, and East 24th Street.

The new tenants: 

• IBM has secured its position as the primary anchor tenant at One Madison Avenue, signing a 328,000-square-foot, 16-year lease.

• Chelsea Piers Fitness with a 55,780-square-foot, 20-year lease.

• Franklin Templeton with a347,474-square-foot, 15-year lease.

• 777 Partners with an 18,746-square-foot, 15-year lease for the entire 27th floor. 

• Palo Alto Networks with a 28,903-square-foot, ten-year lease for the entire 26th floor.

The facilities: The office amenities will feature landscaped outdoor terraces on the tenth and eleventh floors, a 9,000-square-foot tenant lounge, a fitness center by Chelsea Piers Fitness spanning three levels and room for storing bicycles.

Two upcoming eateries: Chef Daniel Boulud will introduce two dining venues at the property: a European-style marketplace along East 23rd Street spanning 9.5K SF, and a Rockwell Group-designed steakhouse with an 800 sitting capacity.

Location, location, location: For transportation, the nearest subway stations to the site are the 6, R, and W trains at the two adjacent 23rd Street stations.