BENTONVILLE — The cost of running two elementary schools on a calendar different from the rest of the School District’s buildings was about $36,000 last year, according to a study by administrators.

The study also found no significant difference in academic achievement between those two schools and others that operate on a traditional calendar.

School Board members received the study results this month. The board requested the study be done before it was time to approve calendars for the 2014-15 school year.

Elm Tree and R.E. Baker elementary schools run on the nontraditional calendar, which has a shorter summer break but more time off throughout the year. Though sometimes referred to as “year-round” schools, they are open for the same number of days as other schools.

Any student who lives in the School District is eligible to attend either Baker or Elm Tree because they are not tied to attendance zones.

Grant Lightle, board vice president, said the cost of maintaining nontraditional schools was his main concern before the study was done.

“We didn’t have any idea,” Lightle said at last week’s board meeting. “We didn’t know, is this a million-dollar decision? This was a smaller number than I would have guessed. That’s $30 per kid.”

The study helps the board decide whether the nontraditional calendar is worth keeping, said Wendi Cheatham, board president.

“We can put a dollar figure to it now,” she said. “We either say we like that dollar figure and we accept it or we say that’s something that’s not of value to us and we’re going to change it.”

Cheatham noted many parents love the nontraditional calendar and she would have a hard time changing something for the sake of change.

Michael Poore, district superintendent, said his recommendation would be to retain the nontraditional calendar. The board has not announced the next time it will consider the issue.

Angela Tymeson has two children at R.E. Baker. The shorter summer break of about seven weeks — compared to 12 for the traditional schools — allow her children to retain more information from one school year to the next, she said.

“Then I love that just about the time we’re ready for a break, we get one,” Tymeson said. “It gives us some time to relax. We’re refreshed and ready to go again.”

The extra cost associated with maintaining two different calendars are because of transportation, utilities and professional development expenses.

Transportation was the highest of those costs last year, amounting to $21,625. The district must run separate buses for the traditional and nontraditional students, said Dena Ross, director of instructional services.

Professional development is another reason nontraditional schools cost more. That training often is done during the summer while traditional schools are off, but occasionally overlaps with days the nontraditional schools are open. That means substitute teachers are needed to cover for nontraditional school teachers.

Professional development costs last school year amounted to $9,793 for the nontraditional schools, which was an above-average year, Ross said.

The other extra expense associated with nontraditional schools is utilities, which was $5,010 last school year. District officials have not analyzed the reasons for that, said Mary Ley, district spokeswoman.

Academically, the district found only slight variations in test data between its nontraditional schools and the traditional schools most similar to them demographically. District officials determined the evidence was inconclusive.

“Any research you see has no indication that the year-round calendar has a positive impact on achievement,” Ross said.

Bentonville is not the only local school district that operates some schools on nontraditional calendars.

Fayetteville has two — Asbell and Happy Hollow elementary schools — and Owl Creek School, a kindergarten- through seventh-grade school, will change to a nontraditional calendar this fall. Rogers School District’s Eastside Elementary also is nontraditional.

Bentonville administrators have discussed converting a middle school to the nontraditional calendar, but surveys have shown a lack of parent interest in doing it at that level, Ross said.

The free and reduced-price lunch rates at R.E. Baker and Elm Tree are 13 percent and 15 percent, respectively. The districtwide rate for elementary schools is 29 percent.

Administrators cited two possible reasons for that.

“Sometimes working families look at that calendar, they see those gaps, and it’s a little bit harder for them to manage it,” Poore said.

Tamara Gibson, a district administrator who used to be principal at Elm Tree, said the limited transportation the district provides to both nontraditional schools is another significant factor.