North Stonington — After a discussion spanning two special meetings, the Board of Finance voted unanimously Wednesday night to approve a $47 million school renovation project.

The vote was the final step for the project before it goes to a public hearing and referendum in less than a month. Originally planning to make a decision Monday night, board members tabled the resolution until Wednesday as they took a hard look at the taxpayer burden - a subject broached by several vocal residents at a public presentation of the plan to the board last week.

Depending on the state reimbursement rate for renovating the district's school facilities "as new" - something the town won't know for sure until they've voted the project through and sent it off to the state in June for approval - the town could shoulder anywhere from $26 million to $31 million of the cost.

The project would include more than 40,000 additional square feet of space for Wheeler Middle School/High School and North Stonington Elementary School, along with a new gymnasium/auditorium on the north side of Route 2. But most pressingly, say school officials, it would resolve multiple health, safety, security and building code issues associated with the age of the facilities, some of which date back more than 50 years.

Board of Finance Chairman Dan Spring laid out the fiscal factors the town has going for it Monday evening: The town will likely retire all of its large debt at the end of this fiscal year - which could mean knocking off 1.5 mills from the current 25.6-mill tax rate - and it has maintained an A1 credit rating, meaning the town has an "excellent capacity" to pay its bills.

On the other hand, Spring said, the town's grand list - standing at about $525 million for 2013 - has not grown over the last two years, which Spring called "bothersome." And the tax burden from the project will join the one taxpayers have already committed to - an additional $6.3 million for a new fire and emergency services complex.

The total debt could be as much as 6 percent of the town's grand list - potentially overstressing the town's fiscal profile, Spring said - and could add up to a tax rate increase of 5 mills during construction.

"To make this project work, it most certainly is going to mean a tax increase," Spring said.

Whether or not the renovations are necessary was not a part of the conversation, Spring said, but rather whether it would be "more prudent" to tackle the project in phases.

"The strength of the approval was certainly the overwhelming recognition of need," Spring said.

But Spring said the board was swayed by historically low interest rates. If the project were broken up in phases, he said, it could actually end up costing the town even more.

This is a point Superintendent Peter Nero and Ad Hoc School Building Committee Chairman Walt Mathwich emphasized at Monday's meeting, while pointing out that the project has been "on the front burner" for more than a decade.

"This is not something that has come up in the last six weeks," Nero said.

If approved, construction on the elementary school would begin next summer and wrap up in a year. Wheeler renovations would be completed in December 2017.

The project will go to a public hearing April 28 and wiwwwll be put to a vote May 5.

a.isaacs@theday.com