Stonington — Voters here overwhelmingly approved the most expensive municipal building project in town history — a $69 million renovation and expansion of Deans Mill and West Vine Streets schools — on Tuesday by a ratio of 3-1.

The vote was 1,496 to 451 with 16 percent of the town’s 12,449 registered voters casting ballots.

“Today is huge for this town. It brings balance and equity to the two sides of town in a meaningful way,” said Rob Marseglia, the chairman of the K-12 School Building Committee, which worked 18 months to develop the plan.

Marseglia admitted after the results were announced in Town Hall that the outcome was a huge relief. Asked about the strong support for the project, Marseglia said “We put together a good project that make sense for the town.”

But he said it was the unanimous support of the boards of finance, selectmen and education along with Superintendent of Schools Van Riley that made the victory possible.

“Without that support we would not have been able to pass this,” he said. “The people of the town got a lot of confidence from that, and I think that’s why they voted 3 to 1 for it.”

Although the Board of Education originally supported building a new middle school and converting the two middle schools for elementary use, school board Chairman Frank Todisco said that “in the end the best plan came forward.

“It’s a well thought out plan that’s fiscally responsible. The K-12 School Building Committee did a thorough job vetting all the possibilities,” he said.

The project, which will cost taxpayers $52.3 million after state reimbursement, will result in two new schools that meet code requirements, contain additional classroom space, larger gyms, new art and music rooms and libraries, updated mechanical systems and more efficient heating systems to replace the costly electric heat in both schools. The schools will also meet educational requirements that did not exist when the two schools were built 48 years ago.

The plan also calls for closing 115-year-old West Broad Street School and moving fifth-grade students from the middle schools back to the elementary schools, where school officials say they should be, according to research.

The project is one that had been discussed by school officials for almost 20 years but repeatedly stalled as the Board of Finance and town officials were reluctant to add to the town’s debt.

The project calls for renovating the original 24,300-square-feet of Deans Mill School, removing portable classrooms and demolishing the 34,150-square-foot addition built in 1973. A 40,400-square-foot addition would be built.

At West Vine Street School, plans call for renovating the 24,300-square-foot school, removing portable classrooms and adding two additions totaling 33,900 square feet. West Broad Street Schools students would be moved to the school. The project also calls for replacing the Pawcatuck Middle School roof.

In addition, Marseglia has said the project creates “financial predictability” for the town as it can plan for the cost instead of being faced with unexpected emergency repairs that are not funded. Those were estimated at $25 million over the next 20 years.

The project would be complete by the fall of 2019 and is designed to get another 50 years of life out of the two buildings.

j.wojtas@theday.com

Twitter: @joewojtas