Stonington — Voters will go to the polls Tuesday to decide if the town should proceed with the most expensive municipal building project in its history — a $69 million renovation and expansion of Deans Mill and West Vine Streets schools, sister schools that are 48 years old.

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 also will meet educational requirements that did not exist when they were built.

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.

“We’ve done an exhaustive amount of work to make sure this is the right project for the town and we hope residents support it. Long-term, we think it will pay off for the town,” said Rob Marseglia, chairman of the K-12 School Building Committee, which worked 18 months to develop the plan.

Over the past two years, the town has had to make emergency repairs to Deans Mill and West Broad Street schools. These include replacing the roof at Deans Mill and repairing collapsed ceiling tiles and a broken sprinkler system at West Broad Street School that closed the library, classrooms and stairwells.

The committee’s analysis showed it would cost the town $25 million over the next 20 years to make repairs to the three elementary schools if no project were undertaken.

“We’ve squeezed as much life out of these two schools as we could and now it’s time to invest in them, it’s time for maintenance and upgrades. It’s no different than maintaining your home over the time you own it,” Marseglia said.

The project is one that has 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 School students would be moved to the school. The project also calls for replacing the Pawcatuck Middle School roof.

Marseglia said the project will create educational equity between the Pawcatuck and Mystic elementary schools. He said the schools will be designed to be as identical as possible.

In addition, he 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.

Marseglia said the project is designed to get another 50 years of life out of the two buildings.

The project would be complete by the fall of 2019. There are several reasons for the four-year time frame.

If approved by voters, the town first needs to submit an application for state reimbursement by June 30. The state will take a year to review the plans and approve the reimbursement. Beginning next summer, architects would need a year to create the detailed designs. Money would be bonded in the summer of 2017 and two years of construction would begin that fall.

The project would be financed over 20 years. For a resident who owns a home assessed at 225,000, the median assessment in town, the project would boost their tax bill by $200 in fiscal 2019 and $300 in 2020. The increase would then slowly decline to no increase by 2027 as the town pays off debt on other projects.

There has been no criticism of the cost of the project by residents at the many pubic meetings and forums held over the past several months.

The building committee rejected a different plan, favored by school officials, that would have cost $113 million. It called for building a new middle school, closing the elementary schools and School Administration Building and renovating the middle schools to be used as elementary schools.

Marseglia said the committee was conservative in its cost estimates, assuming high construction costs and a 5 percent inflation rate, in an effort to ensure the project does not run short of funds. He said this also means the price tag could end up being lower.

“We’ll work to bring down the number we have to borrow. We realize that this is not our money, it’s the taxpayers’ money, so we’re going to be careful with it,” he said. “This is the largest project ever done by the town and we don’t take that lightly.”

Polls will be open from 6 a.m. to 8 p.m. at the following locations: District 1 and 3, Stonington Borough Fire Department; District 2, Pawcatuck Fire Department, and Districts 4 and 5, B. F. Hoxie Engine Co. firehouse, Mystic.

j.wojtas@theday.com

Twitter: @joewojtas