SL Green Converts Midtown East Office Tower Into 639 Homes With Rents Near $7,000
New York City, USA | September 21, 2026: A major Manhattan office-to-residential conversion is taking shape in Midtown East as SL Green Realty transforms 750 Third Avenue into a 639-unit residential tower. The roughly $805 million redevelopment will add housing to one of New York's biggest business districts while offering a clear example of how older office buildings are being repositioned for the city's housing market.
The project will also include affordable housing and is expected to benefit from New York's tax incentives for office-to-residential conversions.
From Office Tower to 639 Apartments
The 34-storey building at 750 Third Avenue is being converted from office use into approximately 761,384 square feet of residential space.
The redevelopment includes:
- 639 residential apartments
- Ground-floor retail
- Coworking space
- Fitness facilities
- Membership club
- Around half an acre of outdoor terrace space
- Rooftop amenities
The conversion is being designed by Gensler, with construction expected to continue through the fourth quarter of 2029.
Developers Are Reworking the Building to Add Light and Air
One of the biggest challenges is the tower's deep office floor plates, which were not originally designed for residential apartments.
The redevelopment plan addresses this by removing nearly 25,000 square feet of floor area from floors four through 17. The resulting notch on the eastern side of the building is intended to improve access to natural light and air.
The lost floor area is being offset by adding 11 floors on the western side of the building.
This approach allows the developer to substantially redesign the existing office structure rather than simply dividing old office floors into apartments.
Market-Rate Rents Could Reach $7,000 a Month
The economics of the project reflect the high cost of converting a large Manhattan office tower into housing.
SL Green's investment plan includes approximately:
- $320 million in cash equity
- $485 million in debt financing
- $805 million total redevelopment cost
Investor projections put market-rate rents at around $90 to $113 per square foot.
An 800-square-foot apartment at the lower end of that range would translate to roughly $7,000 per month, highlighting the premium rental market targeted by the project.
25% of Homes Planned as Affordable Housing
While market-rate rents are expected to be high, approximately one-quarter of the building's apartments will be affordable under New York's 467-m tax incentive framework.
Affordable units are projected at roughly $25 to $45 per square foot, substantially below the projected market-rate range.
The tax programme can provide a major property-tax benefit for eligible office-to-residential conversions, helping developers address the unusually high cost of installing new residential plumbing, mechanical systems, cores and other infrastructure inside older office buildings.
Why Office-to-Residential Conversions Matter
750 Third Avenue is part of a wider shift in Manhattan's commercial property market.
Older office buildings face changing tenant demand, while New York continues to need additional housing. Converting suitable properties can potentially bring unused or underused commercial space into the residential market.
New York City's City of Yes for Housing Opportunity reforms have also expanded conversion opportunities for certain older non-residential buildings.
For property investors, the project highlights several factors that can determine whether an office conversion is financially viable:
- Building age and structural configuration
- Residential zoning eligibility
- Conversion and construction costs
- Tax incentives
- Expected residential rents
- Affordable-housing requirements
- Access to transit and amenities
Project Faces Scrutiny During Construction
The development also encountered a temporary construction issue in July.
New York City's Department of Buildings issued a partial stop-work order involving structural steel work above the eighth floor after inspectors found welding that did not match filed plans.
The order was rescinded two days later following a reinspection, with officials reporting no structural distress or danger to the public.
The episode illustrates the additional regulatory and construction complexity involved when large office towers undergo structural conversion.
Midtown Location Adds to the Project's Rental Appeal
The building sits close to Grand Central-42nd Street, providing access to multiple subway services as well as Metro-North and Long Island Rail Road connections.
That transit access, combined with the project's residential amenities and Midtown location, is central to its rental positioning.
If completed as planned, 750 Third Avenue will add hundreds of homes to a major employment district while creating a new residential asset from an older commercial building.
What Happens Next
Construction is expected to continue toward a targeted Q4 2029 completion.
The project will be closely watched as another test of Manhattan's office-to-residential conversion model. Its combination of 639 homes, 25% affordable housing, high projected market rents and an $805 million redevelopment cost provides a useful indicator of how developers are balancing housing demand, construction costs and the economics of repurposing older office towers.