NORTH STONINGTON — A study presented to the Board of Education Wednesday night estimates that a complete overhaul to the town’s school buildings could cost anywhere from $27 million to $64 million, depending on what option the town would prefer.The public presentation was made by Rusty Malik, a partner in the firm of QuisenberryArcari Architects of Farmington.Malik has worked closely with the board’s Ad Hoc School Building Committee to investigate the buildings, their physical status and ability to meet future needs. The study included the elementary and middle-high school complex; some sections are more than 50 years old.The buildings have several issues of compliance that should be addressed. Security needs to be upgraded at the elementary school and using the multipurpose room as both a gym and cafeteria is problematic.At the middle–high school building, there is a lack of women’s facilities regarding Title IX equality, the science rooms are outdated, security needs to be addressed and students must cross under Route 2 to reach the Gymatorium.“North Stonington has a flat enrollment projection over the next 10 years,” Malik said. “It is not one of the drivers of needing renovations or a new building.”Three options were presented to the board: renovate both schools, with a new gym attached to the high school; renovate both schools with no new gym, and an enclosed walkway under Route 2; and build an entirely new complex.The scenario of a new complex was established in order to establish a baseline of comparison that is required for state funding. Malik estimated the total cost at $87.5 million, with the town paying $57.5 million to $64 million, more than twice the cost of the other two options.In the remaining two options, the elementary school would be for pre-kindergarten to grade six, and the work would be identical. A new gym–assembly hall would be constructed and additional parking added. Classrooms would be shifted such that pre-kindergarten through first grade would be on the ground level with the remainder on the second floor. The multipurpose room would be a dedicated cafeteria with additional rooms for a media and computer technology center.The middle–high school would be for grades 7 to 12. In one option, the present sixth grade would be demolished and a new gym with lockers and a stage would be attached to the existing building. A new addition would also be built as a science center. For this option to meet state funding requirements, the Gymatorium would have to be turned over to the town.In the other option, no gym or stage would be built, but the science center would proceed and the tunnel under Route 2 would be enclosed.“We know what our issues are,” said Superintendent of Schools Peter Nero. “We knew what they were in 2002.”Walt Mathwich, head of the ad hoc committee, said the board must choose an option, which then must be approved by the Board of Selectmen.If the selectmen deem it worthwhile, the proposal would be put before a town meeting for a vote.Malik said that if the town wants to apply for state funding, it must be submitted to the state by June 30.The proposal will be put on the Board of Education’s website within the next day.