Renovations to start soon: The Lithgow Building in Codman Square will undergo a major interior renovation to create classroom space for its new owner, the Codman Academy Charter Public School. Nereyda Rodriguez photo

It won’t be obvious from the outside, but the 115-year-old Lithgow Building that anchors Codman Square is about to undergo a major transformation.

After decades of minimal activity, the three-story brick structure that dominates the intersection of Washington Street and Talbot Avenue will be brought back to life starting this fall when work crews begin a complete makeover of the interior into additional space for the Codman Academy Charter Public School.

“We’re very committed to maintaining the historic character of building,” said Meg Campbell, the school’s executive director. The Georgian revival building’s exterior, including the windows, will remain untouched. The demolition phase of the $12 million project will begin in the late summer or early fall, Campbell said, with as little impact to neighbors as possible. Codman Academy is currently soliciting union subcontractors, she added, and is “deeply committed” to hiring locally.

Scheduled to be ready next summer, the new building will feature 11 classrooms, a dance studio, a science lab, an arts studio, a dining room, and a teaching kitchen. It will also display students’ artwork throughout. Campbell said they’re also hoping to include a window at the street level where local vendors and artists can showcase their wares. “We’re not a school that looks inward; we’re a school that looks outward,” she said.

The school is employing architects with Miller Dyer Spears and contractors from Shawmut Design and Construction, known for their work with historic and academic buildings. And attorneys from Ropes & Gray are working pro bono to iron things out on the legal side of the project. Campbell said the renovation is being funded through a combination of private funding, loans, and New Markets Tax Credits, which spur private investment in low-income communities.

The Lithgow building was designed for Lydia B. Taft, a member of the neighborhood’s successful Baker family, some 120 years after the Bakers founded their chocolate factory in Lower Mills. It was the site over the years of retail space, offices, and a Masonic Lodge, which Taft oversaw for 50 years. The Codman Square Neighborhood Development Corporation obtained the neglected structure in the 1980s.

Codman Academy recently expanded its charter to include grades K1 through 8 to meet its growing demand. The school has received over 1,500 applications for 130 seats that include the ninth grade. “There is very, very strong demand for these seats,” Campbell said.

The academy’s upper school is now housed in the Codman Square Health Center, where it’s expected to remain. Founded in 2001, the school has gained national recognition for its unique partnership with the Health Center. “We’re very connected to the community so people are very excited,” Campbell said.“To open up more quality seats in Dorchester is very exciting for us. For parents, it’s a dream. Their kids get in in kindergarten and they’re done, they’re all set.”