Plans to build or upgrade public schools are taking center stage in Arlington as voters head to the polls Tuesday to consider three proposed tax increases for the projects.

At a special election, residents will vote on debt exclusions, or temporary tax increases, to fund a combined $63 million in school building investments. Together, the increases would add $246 to the tax bill of an average single- family home once all the debt was issued in fiscal 2020.

The tax revenue would pay for $29 million to expand the Thompson Elementary School and renovate the former Gibbs school building; $2 million to study options for a potential high school building project; and $32 million to fund Arlington’s share of the proposed new Minuteman High School.

“It addresses enrollment challenges and building deficiencies from kindergarten to 12th grade,’’ said Jennifer Susse, chairwoman of the School Committee and co-chairwoman of a ballot committee urging a “Yes’’ vote on all three questions.

The twin Thompson and Gibbs projects are designed to address a 17 percent growth in district enrollment since 2005 and the steady increase projected over the next 10 years.

The three-year-old Thompson School would expand with a six-classroom addition. The Gibbs building would be renovated to serve as a townwide sixth-grade school, easing overcrowding at the Ottoson Middle School.

Susse said the plan was the product of a deliberative process in which “we considered all possible angles’’ to address overcrowding. She said the proposed solution was a “very conservative’’ one that would still leave five of the town’s seven elementary schools at or above capacity.’’

Sean Harrington, chairman of the Republican Town Committee, said he supports the Gibbs renovation. But he opposes the ballot question requesting funding for it because he disagrees with the Thompson expansion, believing there are other solutions, such as redistricting, to solve the overcrowding at what is “basically a brand-new building.’’

“It seems to me they have just been focused on the tax increase,’’ said Harrington, who supports the other two debt exclusions.

Susse said by e-mail the town tried redistricting, but four years later, “six of our nine schools are at or beyond capacity. Even if we were to massively redistrict tomorrow . . . we would still not solve our problem.’’

The high school feasibility study would examine the range of alternatives for addressing the physical issues of the school, a needed step in the town’s efforts to secure partial state reimbursement for a project.

Replacement or overhaul of the high school has been a longtime goal of Arlington officials, who note that the school’s accreditation is on warning status due to its physical issues, which include outmoded mechanical systems and an antiquated layout.

“Arlington High School was built in 1914 and its last renovations were done 35 years ago. It is worn from use and its facilities are inadequate for a 21st-century education,’’ Diane M. Mahon, Board of Selectmen chairwoman, said in an e-mail.

The Minuteman district is proposing to build a $144.9 million vocational high school serving in Lincoln 628 students to replace its existing school in Lexington. The Massachusetts School Building Authority has agreed to fund about $45 million of the costs.

The project faces uncertainty because Belmont’s Town Meeting on May 4 rejected funding the town’s share. None of the Minuteman district’s other towns rejected the funding, though Arlington’s Town Meeting appropriation on May 9 is subject to passage of the debt exclusion. The state recently extended to Nov. 30 the deadline for the district to approve its share.

Selectman Dan Dunn said Arlington should support the project “because our kids deserve it,’’ referring to the town’s students — about 120 — who attend the vocational school. And he said the existing facility has numerous deficiencies that have landed the school on accreditation warning.

But a local committee is urging voters to reject the Minuteman proposal while voting “Yes’’ on the other two, according to Charlie Foskett, a member of the group and a Town Meeting representative, vice chairman of the Finance Committee, and chairman of the Capital Planning Committee.

“There are less expensive ways to do what they want to do,’’ he said. “The school has an immense amount of land and building space. . . . Those buildings can be renovated to current standards.’’

Foskett also warned that Arlington, which has the largest number of Minuteman students, is at particular risk of its project cost increasing if the district fails to achieve the enrollment growth it now forecasts.

Dunn said the district considered but rejected renovation as not cost-effective. He said the risk posed by potentially low enrollment “is being managed appropriately’’ by planning for a new school that would be smaller and thus less expensive to maintain.

John Laidler can be reached at laidler@globe.com.