The South Burlington School District has known for years that it has an enrollment problem at the elementary level.

Two of its elementary buildings — Orchard Elementary School and Rick Marcotte Central Elementary School — are already pushing up against their maximum capacity. The other school, Chamberlin Elementary — will likely be in that same position in another five years or so.

“We have highly, highly congested buildings and highly congested classrooms, and we really need to do something,” South Burlington parent Ethan Bellavance said. “If anyone’s looked at any of the data, the lowest-ranked option was to do nothing.”

Bellavance is a member of the district’s all-volunteer enrollment committee. It recently recommended that the district buy four new trailers for both Orchard and Rick Marcotte Central.

The school board voted Wednesday night to approve the committee’s recommendation. The purchase will bring the number of trailers at each of the two schools to eight.

“That buys us that seven-to-ten-year time frame to really figure out — we’ve got a bunch of big, thorny issues with the high school and middle school,” Bellavance said. “What are we going to do here?”

The goal is to have the trailers — officially known as zero-energy modular units, or ‘ZEMs’ — in place by November. The eight new trailers will cost a total of approximately $2 million, but it’s not yet clear how the school district will pay for them.

“Typically, for long-term capital improvements, you use debt instruments,” school board general counsel Joe McNeil said. “And debt instruments require voter approval in advance.”

With this being a short-term project, a bond issuance or other debt instrument won’t be necessary. The trailers can either be leased or financed as a current expense. The district is already trying to figure out which method will cost less. It’ll move ahead with the cheaper option as soon as it knows which one that is.

The South Burlington School Board has also appointed Dr. Lisa Cala Ruud as interim superintentdent, effective July 1, provided the district can reach an employment contract with her. She’s currently the director of academics for the Chatham Central School District in Chatham, New York, which is about 30 miles south of Albany.

Dr. Cala Ruud will serve in South Burlington for one year and can apply for the permanent post if she wishes. Longtime South Burlington School District superintendent David Young is stepping down at the end of the month.