BUFFALO TWP — The Freeport School Board agreed Wednesday night to build a $29.2 million, 110,000-square-foot middle school on its Buffalo Township campus. The building could open by September 2015.

The building for grades 6 through 8 will replace the district’s 90-year-old junior high school in Freeport.

The motion that passed allows the district to make adjustments to the building plan, which Shoaf called a “framework,” but not to exceed the $29.2 million cost.

Shoaf, the board president, said the district successfully stayed on budget when the Buffalo and South Buffalo elementary schools were renovated.

“We are looking at a variety of ways to offset costs,” Shoaf said. “This amount enables the board to minimize (property tax) millage increases.”

Previously, the board anticipated borrowing $25 million for construction and using $4 million already set aside to pay for the new building.

Under that scenario, Butler County taxpayers in a home assessed at $20,000 could pay $200 more annually and Armstrong County taxpayers in a home assessed at $30,000 could pay $141 more annually.

However, officials said on Wednesday that low interest rates, creative financing and savings from budget line items and from closing the Freeport Kindergarten Center could drive down borrowing.