International real estate investment and management firm Harbor Group International LLC (HGI) has provided a $90 million senior mezzanine loan to Extell Development Company to finance the construction of 1520 First Ave., a 30-story, 420,000-rentable-square-foot office building in Manhattan’s Upper East Side. HGI, alongside InterVest Capital Partners, Rexmark and Pacific Western Bank, contributed to the loan financing, which totaled $425 million. Construction of the mixed-use medical office and retail space is expected to be completed in 2025.
Upon completion, the building will feature over 390,000 rentable square feet of medical space, of which 196,000 rentable square feet is pre-leased to the Hospital for Special Surgery, an internationally renowned musculoskeletal health and surgery center. The property will also feature ground floor and lower-level retail space.
“Across the country — especially cities with a high concentration of residents — there’s an increasing need for world-class medical space,” said Richard Litton, president ofHGI. “To support this demand, we are pleased to finance the development of a specialized office space designed to accommodate the unique needs of medical tenants and their patients.”
The Upper East Side contains one of the highest concentrations of hospitals in the country, positioning the property as an attractive leasing option, blocks from leading hospitals, attractions and New York’s Central Park and East River.








