Image courtesy of Corderman & Co.

Developer Jamestown is partnering with Related Beal on a 50-50 joint venture for the future of the Innovation and Design Building in Boston’s Seaport District with a plans to add more office and lab space in 2021.

Jamestown, owner of the 1.4 million-square-foot complex on Drydock Avenue since 2013, has repositioned the former industrial space as a destination for office and lab tenants, a strategy that will continue under the new ownership structure, the companies announced. Terms of the transaction were not disclosed.

Under Jamestown ownership, the complex which was originally part of the South Boston Army Base has undergone over $200 million in updates and attracted new tenants ranging from the headquarters of Reebok and Elkus Manfredi Architects to an autonomous vehicle company and 3-D visualization studio.

In a press release, the partners said construction of additional office and lab space within the existing building will begin in 2021.

The deal is the latest in a series of big-ticket investments in the eastern portion of the Seaport District by major developers.

The Davis Cos. recently proposed nearly doubling the size of the 88 Black Falcon property with a 330,600-square-foot addition. Life science specialist Alexandria Real Estate Equities last month bought a 6-acre site on E Street currently occupied by a self-storage facility and truck terminal for $168.5 million, while Marcus Partners acquired the Au Bon Pain headquarters and bakery on Fid Kennedy Way for $25 million.