HATFIELD - Town officials are close to sealing the deal to let Hilltown Cooperative Charter Public School in Williamsburg move into the long vacant Center School.

"It will take a week or two to put it in writing," said Town Administrator Jeffrey Ritter. He said the document "will contain all the terms and conditions we would like to see in a lease before we hand it off to the charter school."

For Hilltown officials, who have been looking for 13 years for space to relocate from the current quarters in Haydenville, the news seemed almost too good to be true.

"We have gotten excited in the past but we're cautiously optimistic," Amy Aaron, the school's administrative coordinator, said in a telephone interview.

"Hatfield has been on our radar since 2004," said Aaron. "It's been discouraging, but there's a shift in feeling over there."

Initially, Hilltown proposed sinking $4 million to $6 million into renovations to the Center School for plumbing, heating, electrical work and building an addition. "We will do due diligence around cost, see if we can afford it, and nail down a firm figure," Aaron said. "That's our next big step."

Aaron estimated it would take two years to get the new facility ready.

Meanwhile, among the unanswered questions are the issues over the school's playing fields and who will have access to them, and how high the rent will be.

"They are a public school and a nonprofit, so they don't pay taxes," Ritter said. "

He said the question is how much rent the school will pay, and will it cover the lost tax payments.

Hilltown operates out of the Brassworks, a refurbished factory building in Haydenville, and has been searching for suitable new digs for years.

"We hope to have an agreement in place by the first of November," Ritter said.

At Hatfield's May Town Meeting, residents voted overwhelmingly to lease the Center School rather than sell it, with terms of the lease to be negotiated. The charter school has long expressed an interest in a 20-year lease, a fact that fueled the vote to lease. State law prohibits the leasing of a municipally owned building for more than 30 years.

Though it was anticipated that other parties would express interest in the building once requests for proposals went out, Hilltown was the only one that responded.

Ritter confirmed that the town is negotiating with Hilltown.

"The steam's in the boiler and we're putting it in gear," he said.

"We're not banking on anything, but there may be a shift in the town's thinking," Aaron said.

The Center School was built in 1914, closed in the 1980s and has had one tenant since, the Western Mass. Regional Library System, which left in 2004, unable to reach favorable lease terms with the town.

The town has tried to sell the building in the past but voters at Town Meeting three years ago instructed the Select Board to keep and maintain the revered building. But as it languished, the issue of the school's disposition became urgent.

The issue reached a head earlier this year during town elections and the lead-up to Town Meeting. Former School Committee Chairman Brian Moriarty, an unsuccessful candidate for selectman, strongly opposed leasing to Hilltown, as did former interim Superintendent Fran Gougeon. Both said they feared that locating such a school in the center of town would damage Hatfield schools by siphoning students away.

Moriarty's opponent and eventual winner, Jan Joseph Adamski, along with Select Board Chairman Ed Lesko, came out in favor of Hilltown coming to town, citing the potential revenue a lease arrangement would bring.

Three Hatfield students are enrolled at Hilltown, now in its 17th year, with an enrollment of 165 students, 70 percent of whom are from Northampton and Easthampton, according to Aaron. The school has a limit of 180 students.

The charter school uses a blind lottery system to admit students. Meanwhile, Hatfield schools attract significant numbers of school choice students, which many officials, including Lesko, believe would offset any losses to the charter school.

Aside from the idea of moving into an actual school building, there are other factors that make the move attractive to the charter school.

"Our kids play in a parking lot. It would be just wonderful for them to have fields," Aaron said.

Voters at Town Meeting wanted assurance that the town would not lose access to the large playing fields in back of the school, which are used heavily by the Smith Academy field hockey team.

"The playing fields are part of the fabric of our town," said Bob Wagner, of the Community Preservation Committee.

"It's prime land underneath," said Lesko. "It's for our children and our children's children."

He said he believes the town and school would be able to share.

Aaron agreed, saying: "We will come to some agreement with the fields."