A Boston developer filed plans to renovate and expand a 19th-century former mill building in Boston’s South End into a 42-unit residential development.

The Holland Cos. wants to convert the former New England Organ Co. building at 46 Wareham St. into a complex called The Factory at 46 Wareham. The building would also contain 9,400 square feet of ground-floor retail space and 52 underground parking spaces.

The four-story, 30,231-square-foot building is partially occupied by a food importing company. It would be partially demolished, with three additional floors added to create a five-story structure. The brick facades would be restored and new sections would be covered with brick, granite, zinc and metal panels, according to plans filed with the Boston Redevelopment Authority.

The estimated $8 million project would include 23 one-bedroom units, 17 two-bedroom units and two three-bedroom units.

The Holland Cos.’ current projects under construction include the Jordan Lofts at 477 Harrison Ave. and 451 Marlborough.