Voters in Cumberland and North Yarmouth have narrowly approved a plan to build a $9.5 million performing arts center at Greely High School.

The project calls for adding a 500- to 700-seat auditorium and space for music practice, makeup, dressing rooms and storage to the high school in Cumberland Center.

About 51 percent of voters approved the proposal, which passed 5,483 to 5,276. The vote was closest in North Yarmouth, where the plan passed by only 11 votes, 1,334 to 1,323. The two towns make up School Administrative District 51.

The proposed facility will be paid for with a 20-year bond.

The district has planned for a performing arts center for 15 years. In 2011, voters approved a $5 million arts center plan, but rejected spending $1.5 million more to cover increased construction cost three years later.

Advocates of the center have said the current performing arts space is inadequate and a new center is an important asset for the school district and the community. Opponents were worried that the school district was overlooking other improvements needed at its schools by focusing on a performing arts center.