AYER — Ayer School Superintendent George Frost briefed the Ayer Finance Committee Wednesday night on the need for Ayer and Shirley voters to approve $750,000 borrowing authority to pay for a feasibility study for the renovation of Ayer Middle-High School.

The cost breakdown is $100,000-125,000 set aside for a project manager, $450,000 for design work, $150,000 for environmental and site testing and $25,000 in other additional costs.

Frost said the Massachusetts School Building Authority has assured reimbursement of 67 percent of the study cost. Bonus percentage points were earned because it’s a regional school district and because a major portion of the project is reconstruction of an existing school instead of ground-up new construction.

While the term could vary, Frost said five-year borrowing would cost $25,000 in the first year. That amount would be split between the two towns in fiscal year 2012. “From a FY 12 perspective and from an Ayer planning perspective, this is an incredibly prudent move,” said Frost.

The spending for the study would occur in phases. As bills are incurred, Frost said, the state will reimburse the district within one to two weeks of being invoiced.

Unspent borrowing authority would be applied to offset amounts needed to finance the construction project itself.

The fledgling regional school committee has borrowing authority independent from the two towns. However, that authority is capped at two percent of the regional committee’s current $300,000 budget.

Enrollment numbers submitted as part of a prefeasibility application justify the spending, Frost said. The build-out will accommodate a 1,000-student population at the regionalized high school.

Frost said the push is on to try to take advantage of competitive bidding in the slow construction sector. The regional school committee has voted to borrow $750,000. Next the matter must be decided in simultaneous elections in Ayer and Shirley. A blended majority of the two-town vote must approve the borrowing.

With a “yes” vote, Frost hopes the study will begin in late winter or early spring, with a final school plan to present to the 2012 annual town meetings.

“You’re going to have to vote in favor of it or we’ll have to go with another plan,” explained Frost.

“In a perfect world that doesn’t exist,” Frost said ground could be broken on the three-year construction project at the start of the 2013 school year.

“Hopefully it all works and the community gets behind it,” Frost concluded. Frost said a formal pitch will be made to the Ayer selectmen in early December.