(UPDATED on Oct. 21, 2025 at 2:20 p.m.: The first version incorrectly noted that the whole 24 acres of the proposed project were sold. Only 550 Arsenal Street were sold).
Plans to turn the Watertown Mall and other properties on the north side of Arsenal Street into a life science campus appear to be over after the owners of the property sold to a Newton-based development firm.
The Boston Globe reported that Alexandria Real Estate sold the Watertown Mall property in Watertown, which is located at 550 Arsenal St., to National Development for $100.25 million.
National Development’s Chief Investment Officer Andrew Gallinaro told the Globe that the shopping center will remain a retail center, and there are plans to “make improvements and operate it as a first-class shopping center,” but added that “other avenues” may be explored in the longer term.
Watertown Mall is home to Target, Best Buy, the Registry of Motor Vehicles, Joyful Garden, Carter’s, Moda, and Work ‘N Gear. Gallinaro noted that retailers at the shopping center “outperformed.”
In November 2023, Alexandria received approval from the Planning Board for its master plan for a life science-focused development. Plans included 681,616 sq. ft. of new office/lab space in four five-story office/lab buildings, 214,859 sq. ft. total retail space, and 103,727 sq. ft of residential space.
According to property records on the City of Watertown website, Alexandria purchased the 17.85-acre Watertown Mall site for $130 million in 2021, which is $30 million (23 percent) more than the reported sales price for the property to National Development.
Alexandria also owns about 7 more acres of land on that side of Arsenal Street which were to be part of the life science campus. The Middlesex Registry of Deeds does not have records of recent sales of any other properties on Arsenal Street.
In recent years, the life science market has cooled. City Manager George Proakis has noted that several properties in Watertown have permitted life science lab projects, but have not started construction.
In his Oct. 14 Preliminary FY27 Budget Overview presentation, Proakis said: “The biotech industry, it is still growing in the greater Boston area but at a slow enough pace that it is not resulting in new construction.”
National Development‘s description of its portfolio is: From mixed-use projects that combine retail, hotel and residential to senior housing, industrial, life science, and commercial office, our award-winning projects enhance the communities in which we build.
Other properties owned by National Development include 99 Coolidge (the new development on the former Mount Auburn Club site), and 7Ink and the Longwood Center in Boston.