Groton - Preliminary estimates show the school building options being considered so far in Groton would cost $140.7 million to $170.5 million, a task force learned Thursday night.

The estimates were provided by a consultant to the School Facilities Initiative Task Force to illustrate the relative cost of choices such as building one middle school or two. The estimates were not intended to be final, as they exclude many factors such as the cost of acquiring land, if that's needed. They are based on typical school construction costs.

However, the figures were large enough that committee member Wes Greenleaf, former school facilities director, said the task force might have to rethink its approach.

"I think we've got to go back just a little bit and see if there's a cheaper way to do this," he said.

The architectural and engineering consulting firm SLAM, based in Glastonbury, provided estimates for several building options, showing the total cost as well as the cost to Groton after state reimbursement.

Some options and their costs include:

• Build one new middle school for 1,000 students, renovate West Side and Cutler middle schools as new and use them as elementary schools for grades pre-kindergarten through 5, and demolish S.B. Butler, Pleasant Valley and Claude Chester elementary schools. Total cost: $140.67 million. Cost to Groton after reimbursement: $77.51 million.

• Build two new 500-student elementary schools for grades pre-kindergarten through 5, renovate West Side and Cutler middle schools as new and demolish Butler, Pleasant Valley and Claude Chester elementary schools, plus the portables at Charles Barnum and Mary Morrisson elementary schools. Total cost: $148.56 million. Cost to Groton: $79.84 million.

• Build two 500-student middle schools, renovate Cutler as new to use as an elementary school for grades pre-kindergarten through 5, renovate West Side as new to use as an elementary school, and demolish Butler, Pleasant Valley and Claude Chester elementary schools, plus the portables at Charles Barnum and Mary Morrisson elementary schools. Total cost: $161.45 million. Cost to Groton: $92.56 million.

The consultant also provided estimates of building a single or two middle schools with space for 1,200 students.

Mike Zuba, a representative of the educational consultant Milone & MacBroom, said the firm needs more guidance from the group about what it wants before it can provide more specific figures.

The task force took a straw vote of 11-4 in favor of one middle school.

Task Force Chairman Jon Heller said he felt the group was moving too fast; he pointed out that members were absent from the meeting and the task force has yet to conduct and get the results of a survey of 400 voters.

"We are not the electorate," Heller said.

But task force member Enrico DeMatto disagreed.

"We were charged to give our opinion," he said. "Let's give our opinion."

Zuba said the firm has looked at about 34 different sites as potential new school locations and narrowed the list to 10.

He said two properties owned by the town could be used for a 1,000-student middle school: a piece of land off Flanders Road and a property next to Robert E. Fitch High School.

He said the property available near Catherine Kolnaski Magnet School probably could not accommodate a large middle school because it's split by power lines, so the school building and its parking or athletic fields would also be split.

Greenleaf suggested the group consider a less expensive alternative: Build a single but smaller middle school for grades 7 and 8, make minor renovations to Cutler and West Side middle schools so they can be used as elementary schools, and build or renovate an elementary school in the future if there's not enough space.

d.straszheim@theday.com