Developer Charles Batchelder of Waltham wants to replace an old industrial building on Boston Street and a garage on Enterprise St. with a five-story residential building with commercial space on the ground floor - and to extend a road that now runs through the new South Bay mall to Boston Street.

In a letter of intent filed with the BPDA, Batchelder is proposing 260 parking spaces in an underground garage and 25 on-street spaces for the 400 apartments or condos and 18,000 square feet of commercial space in a building with three wings.

The Boston Business Journal first reported on the proposal.

The letter describes the proposal as "transit oriented" because it is near the Newmarket stop on the Fairmount Line and less than a mile to the Andrew stop on the Red Line.

Through the letter, Batchelder is proposing to have the BPDA designate the nearly 4-acre site as a "planned development area," which would throw out its existing zoning and let him and the BPDA negotiate just what he can build without needing to go before the Zoning Board of Appeal.

The land is now split between a commercial zone and a zone meant for three-family houses. Batchelder's letter says the project would not exceed the commercial zone's density and height maximums.

Part of the proposal includes extending District Avenue, which now dead-ends at Jan Karski Way, to Boston Street.

Batchelder is also proposing 1.8 acres of public open space on the site.

Jan Karski Way Extension letter of intent (329k PDF).