SOUTH PORTLAND – A developer has unveiled a proposal for creating a mix of housing and businesses on the site of the old Maine Youth Center.

Richard Berman’s draft master plan calls for 288 units of affordable and market-rate housing. Also proposed are an office building, a small eatery, a community center and public trails and water access.

The project was designed in accordance with the state’s Great American Neighborhood standards. A large tract of green space dominates the center of the proposed development; a neighborhood garden also is included.

“Usually, developers come in with a project and ask the public what they think,” said Berman, who also developed the 33-unit Unity Village in Portland’s Bayside. “We’ve said, ‘What do you want?’ And we’ve tried to provide that.”

The old youth center was replaced by the modern, self-contained Long Creek Youth Development Center on a separate section of the property. Berman’s plan calls for utilizing the old buildings and creating new ones, as well.

Berman, who could lease the 40-acre campus from the state for 50 years, said it will take many partners to make the project work. It also would require a zoning change as well as Planning Board review.

The state is holding onto the title for the former campus in case it is needed in the future to expand the new Long Creek Youth Development Center.

Ed Suslovic, a consultant working with Berman, said he would like to see the state grant a longer lease, such as 90 years.