The Zimmet Law Group, a law firm with diverse practice areas ranging from family law to real estate transactions, is relocating its practice within Manhattan's Plaza District. The firm has signed a lease for 5,476 square feet at 515 Madison Avenue from GFP Real Estate, a building also known as the DuMont Building, located at the eastern end of 53rd Street.
This 42-storey office tower is located just one block south of Zimmet Law Group's previous premises at 477 Madison Avenue, which is owned by RFR Holding. The law firm was represented in the transaction by Elliot Zelinger of Savitt Partners. For the landlord, GFP Real Estate, Martin McGrath and Kephra Stone led the negotiations.
Lease Details and Market Conditions
The Zimmet Law Group is expected to move into the new premises at 515 Madison Avenue later this year, once the fit-out of the space is completed. The exact rent for the almost ten-year lease was not disclosed. However, according to data from Cushman & Wakefield, the average asking rent for office space in Midtown in the second quarter of 2026 was $88.50 per square foot.
Earlier this year, GFP Real Estate took full ownership of the 350,000 square foot Class A tower. This followed an $86.5 million refinancing agreement with Apple Bank, which facilitated the acquisition of ATCO Properties & Management's remaining 40 percent stake in the property.
Current Developments at 515 Madison Avenue
By the end of February, the owner had already secured new leasing activity totalling 12,000 square feet, according to Commercial Observer. In late July, GFP announced further lease agreements totalling 9,000 square feet.
- —Investment firm T7 Capital
- —Aesthetic training provider Innovation Training Specialist
- —Widowski Law Group
Other tenants at 515 Madison Avenue include alternative asset manager Whitebox and therapy provider Manhattan Psychiatry Group.
