Exclusive: Regeneron Pharmaceuticals to Propose Massive New Project in Westchester ‘Very Shortly’

John Jordan • July 22, 2021

WHITE PLAINS—Officials with Regeneron Pharmaceuticals Inc. told members of the Westchester County Industrial Development Agency this morning that it expects to come before the agency “very shortly” with a major new development project in the Town of Greenburgh.

Although Regeneron representatives did not provide any details on the new project, its representations at the session point to a parcel of land where the firm has previously secured approvals from the Town of Greenburgh for the construction of a group of buildings that could total approximately 1 million square feet at 555 Saw Mill River Road.

At the July 22 session, Janet Giris, a partner with the law firm DelBello, Donnellan & Weingarten, Wise & Wiederkeher, LLP and Dale Fanning, executive director-tax operations at Regeneron Pharmaceuticals, when questioned by IDA members, promised that the company would be back before the IDA “as soon as possible” on the new development project. They also said that the company would soon be filing plans for a day care facility on its property with the Town of Mount Pleasant.

When asked when Regeneron might introduce the larger development project, which is owned by an entity of the company, Giris said, “As soon as we can.”

The Tarrytown-based firm is currently before the IDA concerning a project estimated to be valued at $480 million that involves the construction of a new two-story, 207,000-square-foot building, along with a parking structure and other infrastructure. That proposal is an amendment to a plan previously approved by the Westchester IDA known as the Parcel D project that significantly raises the level of investment by approximately $331 million to $480 million. The original plan called for the construction of a building totaling approximately 128,000 square feet of mixed lab/office space. The firm is now seeking a total of $7.7 million in sales tax exemptions in connection with this project from the IDA.

Giris and Fanning had no further comment on the company’s plans when questioned by Real Estate In-Depth. The IDA heard a cost-benefit analysis presentation on the Regeneron project. The study estimates that the $480-million project will create approximately 1,624 jobs during the construction phase and 505 jobs once operational. Construction on the Parcel D project before the IDA is expected to begin later this year with move-in scheduled for mid 2024.

While no development cost for the new project is known, if the firm moved forward with its full 1-million-square-foot development potential, it would easily dwarf the nearly $500-million project currently being considered by the Westchester County IDA.

It should also be noted that Gov. Andrew Cuomo announced on July 16 that Regeneron has plans to spend approximately $1.8 billion on its Westchester County expansion plans. The governor noted that the firm had considered several other out-of-state sites before deciding on investing in the properties it owns in Greenburgh.

Westchester County IDA Chairman Joan McDonald thanked Regeneron for remaining in New York State and promised the county would help the firm in its recruitment efforts in connection with its expansion program.

In the governor’s announcement last week, state officials noted that Regeneron intends to substantially expand its research and development capabilities in Tarrytown, which will include the addition of new preclinical manufacturing and process development suites, laboratories and office space. The project will encompass the design and construction and fit out of up to eight buildings, three parking garages and a central utility plant totaling approximately 900,000 square feet. Road infrastructure improvements will be necessary to support additional buildings at their existing headquarters and R&D campus. The project is planned to take place in two phases over six years.

The company will expand its research, preclinical manufacturing and support facilities at the company’s Westchester County campus and create 1,000 new full-time, high-skill jobs in the Mid-Hudson region over the next five years. Gov. Cuomo said that in return, Empire State Development is offering the company up to $100 million in Excelsior Jobs Program tax credits if its hiring goals are achieved.

By Alexander Roithmayr April 23, 2026
HGAR’s advocacy centered on eight key issues spanning REALTOR® practice, fair housing, and policies aimed at strengthening homeownership and expanding housing supply.
By Real Estate In-Depth April 23, 2026
High home prices, limited inventory, and elevated mortgage rates have made it more difficult, particularly for first-time buyers, to enter the market.
By Real Estate In-Depth April 23, 2026
Bronx Week has historically highlighted everything that makes the Bronx unique: its diversity, entrepreneurial energy, and deep sense of community.
By Real Estate In-Depth April 23, 2026
New York State recently announced the groundbreaking of Westchester Crossing, a major infrastructure investment on the former United Hospital site in Port Chester.
By Real Estate In-Depth April 23, 2026
In today’s commercial real estate environment, the biggest opportunities are no longer tied to the biggest assets.
By Real Estate In-Depth April 20, 2026
Often referred to as a “pied-à-terre tax,” the plan would introduce an annual surcharge on certain luxury properties that are not used as a primary residence.
More