FREEPORT, Maine — After planners presented a nearly $16.9 million expansion proposal for Freeport High School last week, officials in Regional School Unit 5 are hopeful about support for the project.

But they could have their work cut out for them with voters in Pownal and Durham.

The School Board will vote Wednesday, Jan. 23, on whether to move to the project to a June referendum in Freeport, Pownal and Durham. If passed, construction is expected to begin in 2014 and be completed in 2016.

The conceptual design, part of more than a year’s worth of work, renovates the school and recommends several additions, including nine new classrooms and an eight-lane track with an athletic field.

“I think the presentation is very compelling and that this is not an effort to create some fabulous, new unneeded school,” School Board Chairman Nelson Larkins said. “What this is is a plan for practical and necessary improvements and growth.”

The most pressing concerns are safety and overcrowding, according to the report.

Enrollment is projected to increase from 540 students now to more than 650 in the next decade, Superintendent Shannon Welsh said. The additions will help accommodate those students and allow for the possibility of future growth by equipping a proposed 31,000-square-foot addition to support a third floor and leaving the potential to convert student study areas into classrooms.

“The hallways are crowded and the classrooms are maxed out,” Welsh said. “This year enrollment grew 3 percent. If we continue to grow as projected, we’re going to need more space.”

As it’s designed, the expansion could handle up to 800 students, said Kim LaMarre, chairwoman of the high school study committee that made the recommendations.

The new track and field will be built behind the school and will include facilities for discus, shot put, high jump, long jump, pole vault and javelin.

The high school is one of three similarly sized high schools in Class B that does not have its own track and field, making competition scheduling difficult, plan proponents said. The existing field will be used as a multi-purpose practice field.

The new facility would be open to residents from all three towns.

Other key changes to the building include new Science Technology Engineering and Mathematics programming, updated computer labs, a new entrance and bus drop-off, additional visitor parking, and the construction of a new kitchen and food court. The existing cafeteria would be converted into space for the school library.

The renovation also will make the building more accommodating to the requirements of the American’s with Disabilities Act.

The building, which dates back to 1961, has had previous additions in 1986, 1974, 1985 and 2003, according to the report. The most recent addition added six science classrooms and a performing arts center.

The proposed renovation would extend the life of the building approximately 30 years, Welsh said.

The expansion report by PDT Architects in Portland estimates that more than $1 million was taken out of the final proposed budget. The report was endorsed by the Freeport High School Study Advisory Committee, which included educators, parents, students and other community members.

The higher-priced items the report excludes are mostly sports items, including field lighting, more tennis courts and bleachers.

Larkins said he knows the bond is large, but hopes voters understand the expansion is necessary and that planners removed items that were not essential.

“It’s obviously lot of money, we understand that,” he said, noting that they will eventually provide an accurate breakdown of costs to taxpayers in all three towns. “The key for me is that it’s absolutely necessary. They have to understand that it’s not all at once, we’re at historically low interest rates and, with a 20-year bond, that makes it much more feasible and we’ll spread it out over a community. … I hope we can prove it is very necessary and economically feasible.”

Larkins said they still hope to be able build the items that were left out, but that money will have to be raised privately.

Town Council Vice Chairwoman Kristina Egan, the liaison to the School Board, said she agrees the project is a good value and that it’s not unreasonable.

“It’s a necessary project for the future,” Egan said, emphasizing the technology upgrades. “The school is crowded now and it’s only going to get worse. Our kids need a 21st century learning environment to be part of a 21st century economy.”

Egan said the current school’s overcrowding could also be problematic in emergency situations.

“I don’t think we have a choice,” she said. “We’ve got safety issues and we need to something about that. The most fiscally responsible thing to do it to try to make the site we have work.”

Pownal Board of Selectmen Chairman Timothy Giddinge said he acknowledges the needs of the school, but doesn’t know how the bond will fare if it goes to a vote.

“The RSU and this committee are going to have to do a lot of education in Pownal,” Giddinge said, noting that the rehabilitation of the school is a good way to save money. “It’s a hard sell in Pownal. It will help the RSU If they take a serious look at the recommendations and try to pare it down some. Residents of all three towns realize it’s a tough economy and that [the board is] doing their best to keep the cost low.”

In 2011, district voters rejected a $3 million sports field and approved a $24 million RSU 5 budget, although Durham and Pownal both voted against the spending; Freeport carried the plan with an overwhelming majority in favor.

Giddinge said he wants the board to explore other options, such as paying for student tuition at other schools, before they go ahead with the project.

“I think the [Pownal] community stands behind the school, we always have,” he said. “There just needs to be a lot more education for residents of all three towns for why this is needed, how it all came about and why we’re spending the money.”