Image courtesy of DiMella Shaffer

Assembly Row owner Federal Realty Investment Trust is ready to build another 318 housing units at the Somerville mixed-use development, replacing a temporary parking lot currently used by customers of its retail tenants.

The 8-story building would occupy a 1.4-acre parcel known as Block 9 within the 45-acre development on the Mystic River once occupied by a Ford Motor Co. plant and later a strip mall.

The Rockville, Maryland-based retail REIT submitted plans this week for an 383,247 square-foot building at 375 Harold Cohen Way.

Developers are seeking to lease the nearly 13,000 square feet of ground floor commercial space to uses including a daycare and restaurant, according to application materials.

Located next to the Alta Revolution apartments, completed in 2022, the building would include a 20 percent income-restricted component to comply with Somerville’s inclusionary zoning, and 149 garage parking spaces.

The parking spaces would be sold or rented to residents separately from the apartment leases, according to a traffic report by consultants VHB.

The project requires approval of a special permit by the Somerville Planning Board.

Since 2014, Federal Realty has developed more than 1,500 apartments and condominiums, 800,000 square feet of retail space and 1.1 million square feet of offices. But amid the lingering life science leasing slump, Federal Realty has delayed construction of a lab building on one of the remaining building sites.

This week’s proposal is the second major multifamily project moving forward in Somerville this year after a lull in large-scale projects following completion of the 450-unit Prospect Union tower in 2023.

A partnership of Samuels & Associates, Mark Development and Beacon Communities plans to break ground this summer on a 319-unit residential project at 299 Broadway.