Extell Development Company has announced it will be developing the first Class A medical office building on Manhattan’s Upper East Side at 403 East 79th Street.
Located on the East 79th Street corridor, in close proximity to the city’s top hospitals and medical research centers, the 30-story, 400,000 s/f building will be a new construction state-of-the-art facility for the healthcare industry.
The building’s anchor tenant will be Hospital for Special Surgery, the world’s leading academic medical center focused on musculoskeletal health. HSS has signed a long-term lease for approximately 200,000 s/fof space spread across the first eight floors. The space will be filled with HSS physician offices and ancillary services for treatment of musculoskeletal conditions, which affect one out of every two people over the age of 18.
“As the population ages and in anticipation of increased life expectancy, several medical expansions and redevelopments are already underway on the Upper East Side; however, the current medical office inventory is not equipped to meet the modern tenant’s needs,” said Gary Barnett, Chairman and Founder of Extell Development Company.

“403 East 79th Street will provide a much-needed new facility to complement the area’s growth. We are pleased to be partnering with HSS, the foremost hospital for orthopedics and rheumatology to anchor the base of the building.”
“We are grateful to Extell for building a superb facility that will help us to continue lead the world in specialized patient care, research, innovation and education,” said Louis A. Shapiro, President and CEO of HSS. “This is an important step in the multi-year transformation of our main campus, and complement to construction of the HSS Kellen Tower over FDR Drive, which is now underway.”
The full block site, located on the east side of First Avenue from 79th Street to 80th Street, consists of 10 different parcels that took Extell over a decade to assemble. With the site fully entitled and cleared, the company anticipates breaking ground at the end of first quarter 2022 with completion slated for early 2025.

Designed by New York-based Perkins Eastman Architects, the mixed-use building will set a new bar for medical office and research space. The project will feature the latest in modern, user-centered design, infrastructure, and technological specifications. In addition to oversized windows that will offer expansive views and an abundance of natural light, the building will incorporate post-COVID enhancements and specific healthcare solutions, including increased ventilation and enhanced filtration throughout the building. There will also be accommodations for both Department of Health (DOH) and Article 28 requirements for uses such as an Ambulatory Care and Surgical Facilities.
The site’s large footprint allows for efficient floor plates with mostly column free spaces permitting maximum flexibility for tenant fit outs and future improvements and changes in configuration. The building will also include prime retail space on the cellar and ground levels.
Avison Young President & Managing Director of New York City Operations Mitti Liebersohn and Principal & Tri-State Chairman Arthur Mirante represented HSS in the negotiations in collaboration with the hospital’s in-house team of Michael Calabrese, Stephen Bell and Stacey Malakoff. Extell was represented in-house in addition to Avison Young Principal Vincent Carrega.