The next phase in the redevelopment of the Baker Chocolate plant on the Neponset River will finally begin this fall, according to the Boston development firm that has controlled the property for much of the last decade. The long-delayed project promises to salvage several historic brick structures on the scenic Lower Mills riverbank, add several new buildings and add close to 80 new units to the neighborhood's real estate portfolio.

Once completed, the new units will be rented out for the first five years and then sold as condominiums, according to John Graham, president of the Baker Condominium board of trustees and a five-year resident of the existing condo complex, which presently houses 98 units.

"They are condominiums," said Graham, "but under the agreement for historic tax credits from the state they will be rental units for the first five years."

Larry Curtis, a managing partner for Winn Development company, said Tuesday that final design elements of the buildings' interiors are now being finalized in hopes of beginning construction as soon as September.

Most of the housing units will be carved out of the presently vacant Baker Mill building which fronts on Adams Street and overlooks the river, just next to the Baker Dam. Sixty-one units of housing will be situated in the existing red brick building. Another 18 units will be housed in new, brick townhouses at the rear of the property.

Curtis explained that earlier plans to transform the properties into condos immediately "languished" due to financing hurdles that have been alleviated with the state and federal tax breaks afforded the company through its historic restoration plans.

"The rehab costs were such that the condo market, while escalating, didn't go to level that gave sufficient market value," Curtis said. "It has been reconstituted and we now have the approval of the condo association that puts a master deed in place from the beginning. That allows us to access the value of historic tax credits at the property. The incentives provided by state and federal (credits) allow us to do the same exact, first class rehabilitation and allow the numbers to work."

Curtis estimated that the one and two bedroom units would be rented for approximately $1,700 to $1,900 per month. Once they are changed over to condos, he said the market would determine exact pricing, but estimated the average unit would fetch between $400,000 and $500,000.

Curtis said that the construction of the phase two development should take "about 12 to 15 months" to complete.

"The good news is we're ready to go and we're very much looking forward to working with the community to take care of an eyesore," Curtis said.

Graham said that residents in the Baker Square complex - who voted to approve Winn's plans last fall - are eager to see the work begin.

"I don't think there's any question about the mood of the residents," said Graham. "To know that that building is going to be totally rehabilitated has had a very positive effect on the residents and there seems to be some indication that its had a positive effect on the property values."

Graham said that the vacant building, connected to the active condominium complex by a defunct footbridge, previously made "some buyers hesitant."

"They didn't know what was going to happen with that building," Graham said, adding that other developments in the area, including high-priced condos at Milton Landing, a new Shaw's supermarket which opened two years ago, the re-opening of the Roper Bridge over the Neponset, and a proposal for more condominiums on River Street, "appear to be having a very positive effect on property values."

"All of that together has had a positive effect and what we've heard here in the Lower Mills community is extreme satisfaction," said Graham.

Winn purchased the development rights for the vacant Baker Mill building in 1997 and has had several false-starts before. An early version of its build-out plan called for the creation of 202 new condo units. The current plan follows a scale that has been in place for several years, incorporating plans to restore the Baker Carriage House and the Power House, using their interior space for parking. The 200-foot-high brick smokestack- a final, unused remnant of the old chocolate factory complex left behind by the Baker Company- will also be preserved.

The Baker Chocolate Company left Dorchester in 1965 after its parent company, General Foods, relocated its plant to Delaware. The Baker factory had been in continuous operation in Lower Mills since 1765.