Image courtesy of Stantec

The developer of a 19-story lab tower in Somerville’s Assembly Square is seeking an extension to redesign the project following a change of ownership and continuing sluggishness in life science leasing.

The 596,000-square-foot project at 120-132 Middlesex Ave., originally known as Brickyard at Assembly, was approved in 2020. If developers don’t obtain a building permit by May 5, the special permit will expire.

DWCH Assembly Row LLC, a real estate entity affiliated with developer DivcoWest, acquired the Middlesex Avenue parcel and 9 Cummings St. in December 2021 for a combined $24 million, according to data compiled by The Warren Group, publisher of Banker & Tradesman. The site formerly included a church and small office building which were demolished in March 2023.

Developers are seeking a two-year extension to redesign the project and amend the master plan special permit, according to a submission to the Somerville Planning Board by attorney Darren Baird of Goulston & Storrs.

Since acquiring the property, the new development team has met with Somerville officials and neighborhood residents and worked on updates to the project’s mobility study while moving ahead with site preparation work, the letter stated.

While a new life science building in Somerville’s Brickbottom district near the Cambridge line already has leased 90 percent of its space, major lab developments in Assembly Square are nearing completion without commitments.

The Brickyard project is located just north of Greystar’s 74M lab tower and BioMed Realty’s Assembly Innovation Park projects, both of which broke ground on speculation and have yet to announce any tenant leases. The two buildings under construction total 960,000 square feet. In addition, Greystar has filed a proposal for 1.4 million square feet of office and lab space in two new towers nearby, along with a 200-key hotel.

Editor’s note: This report has been updated with a correct image of the approved Brickyard project.