Residents of Regional School Unit 14 in Windham and Raymond will vote Wednesday on whether to change the formula used to split education costs between the towns.

The new cost-sharing structure would increase the tax burden for Windham residents, decrease the cost to Raymond residents, and change how capital improvements are paid for, according to the district’s plan.

School board officials already unanimously approved the new plan in January, but residents must weigh in before it can go into effect.

Based on the current cost-sharing formula, Windham pays 55 percent and Raymond pays 45 percent of costs that exceed the state-required minimum. The cost-sharing formula was determined when the combined district was created in 2008, and was based on three previous years’ education costs in each town.

The new formula, however, is based on the value of property in each town, and would mean Windham would pay 64 percent of school costs, with Raymond paying for 36 percent.

Based on 2015 costs, and for a home worth $250,000, a Windham resident would eventually pay $51 more toward education. A Raymond resident with a home of the same value would pay $90 less.

If the new measure passes, it would be phased in over three years.

The proposed change comes as Raymond examines whether it will withdraw from the district, amid questions about costs for school building upgrades.

The vote Wednesday would address this concern, reformulating how capital improvements are paid for between the towns. The new configuration would place the majority of the cost for a major capital expense on the community of the school where the capital improvement is to take place.

The vote will be held at 5:30 p.m. Wednesday in the Windham High School Auditorium.

This story was updated at 10:15 a.m., March 24, to correct the time of the meeting.