Rudin Files Plans to Convert 845 Third Avenue Into 411 Apartments

Rudin is moving forward with a planned office-to-residential conversion in Midtown East.

Paul Mandel, vice president at Rudin, has filed plans to convert the 21-story office building at 845 Third Avenue into a residential building with 411 apartments, according to a Monday filing with the New York City Department of Buildings.

Michael Rudin, co-CEO at Rudin, hinted at plans for the project at 845 Third Avenue — as well as a similar conversion at its 355 Lexington Avenue office building — in May, as Commercial Observer previously reported.

If approved, Rudin’s Third Avenue project between East 51st and East 52nd streets would include apartments on the second through 21st floors, plus 9,103 square feet of retail space on the ground floor, according to the filing. The project would also feature amenities such as a party room, a gym, a spa, a sauna, a plunge pool, media rooms and coworking spaces. The estimated job cost is $41.7 million, the filing shows.

“This application filing is a significant milestone in our planned conversion of 845 Third Avenue to residential use,” a Rudin spokesperson said in a statement to CO. “Our adaptive reuse project will serve as an important next chapter for a building the Rudin family developed more than 60 years ago, and add desperately needed new apartments to New York City’s housing supply.”

A spokesperson for CetraRuddy Architecture — the listed architect on the project — did not immediately respond to a request for comment.

The office tower at 845 Third Avenue — which Rudin built and developed in 1963 — has seen a slowdown in leasing recently, with the most recent deal signed in October 2023.

Michael Rudin told CO in May that the company has “assessed every single asset to make sure that we’re thinking about them in the best way possible” from both an “operational perspective” and “a shareholder and family perspective.”

News of the project comes after CO reported in February that Rudin was considering an office-to-residential conversion at 355 Lexington Avenue, and had already told the building’s tenants they might need to find new offices.

Rudin joins a wave of landlords looking to convert their aging office properties in Manhattan, including Metro Loft Management and Quantum Pacific at 767 Third Avenue, SL Green Realty at 750 Third Avenue and The Feil Organization at 140 West 57th Street, to name a few.

Isabelle Durso can be reached at idurso@commercialobserver.com.