The owners of the existing South Bay big-box mall this week filed plans with the BRA for a 10-acre extension that would feature residences, a hotel, a movie theater, restaurants and shops in the sort of urban outdoor ambiance city dwellers now have to drive to Dedham or Foxboro to experience.

In a "project notification form," Edens says it will replace a concrete plant, the former 88 supermarket, a closed office building and a vacant warehouse with 475 apartments or condos - 61 of them marketed as affordable - a 12-screen cineplex, a 130-room hotel and room enough for the sort of boutiques and restaurants one doesn't associate with the current South Bay mall.

South Bay Town Center would come with 1,066 parking spaces. But unlike at Legacy Place in Dedham, which consists of stores clustered around a large parking lot, most of the spaces at South Bay Town Center would be "tucked away from view in structures." Sidewalks would connect the mall to Newmarket station on the Fairmount Line and Andrew station on the Red Line.

In its filing, Edens explains its concept:

"The Project entails the redevelopment of a series of under-utilized parcels into a vibrant, transit-oriented, mixed-use neighborhood that could catalyze future development in its surrounding context and provide walkable amenities for adjacent residential neighborhoods. ... The Proponent and the Project Team recognize the intimate relationship between successful retail and quality public space, enhanced by texture and scale oriented toward the pedestrian. The Project represents a departure from the existing suburban-style shopping center at the existing South Bay Center, with the implementation of a new, urban street grid, pedestrian orientation, mixed land uses, structured parking, and acute attention to the details of dynamic public space.

"The Project Team aspires to introduce an exciting urban context influenced by the rich character and heritage of Dorchester- a destination that is new and vibrant, yet an extension of the fabric surrounding it; a place with authenticity and local essence, where residents and visitors alike comingle in a comfortable and energized atmosphere. The Proponent's efforts to thoughtfully merchandise through the selection and location of retail tenants, artisans, and dining concepts, to program both interior and exterior spaces, to artfully integrate materiality and landscaping, and to conceive events engaging the community, promise to create a lively public environment. The urban streetscape and public space create the heart of the Project, harboring activity, outdoor dining, and human interaction. Sidewalks are lined with transparent storefronts of designs unique to each retailer, thus ensuring visually compelling promenades. The social, cultural, and economic activity engendered by the project can provide an impetus for positive change to abutting, antiquated commercial and industrial properties, helping to provide a bright future for Dorchester and the City of Boston."