The Loudoun County School Board will partner with western Loudoun’s Hillsboro Elementary School community to prepare an application that would transform the historic school into a public charter program.

The School Board voted unanimously at its meeting Tuesday to join the school in initiating the charter proposal, a partnership that will allow the application to bypass a preliminary state review and begin the process at the county level.

Hillsboro Elementary is among a handful of historic, small-town Loudoun schools that have been repeatedly threatened with being closed during annual budget discussions. It is the second school in Loudoun to pursue a public charter program as an alternative to shutting its doors. In March, the School Board approved a community-led application to convert Middleburg Elementary School into a year-round, project-focused charter school. The Middleburg Community Charter School, Northern Virginia’s first public charter program, began its inaugural year Aug. 4.

Schools such as those in Middleburg and Hillsboro have been increasingly vulnerable during tense budget deliberations in recent years, with the School Board turning a wary eye toward the cost of operating aging buildings that serve a small number of students. Last year, school system leaders warned the county’s oldest and smallest schools that they would be likely to close if viable alternatives were not pursued.

The months-long Middleburg charter application process was closely followed by other parents in western Loudoun, including residents of Hillsboro, where the community has worked on an application to transform its 140- year-old school into the proposed Hillsboro Charter Academy. The application was presented to the School Board at Tuesday’s meeting.

Like Middleburg, Hillsboro Elementary has typically served a small student population, with just 65 students enrolled for the 2013-2014 school year. But the publicity surrounding the possibility of a charter program led to a rise in enrollment of 15 percent for the upcoming school year, according to the application — the first time in years that enrollment at the school has increased.

“These are parents who are early movers but will soon be followed by many more who seek to enroll their students in [Hillsboro Charter Academy] upon approval of the charter,” the application said, noting that enrollment at the Middleburg school increased dramatically with the launch of its charter program. When the Middleburg school opened this month, about 120 students were enrolled, roughly double the previous year’s student population.

Hillsboro Charter Academy aims to enroll at least 160 students in an “experiential, project-based” academic program, the application said. The school would focus on science, technology, engineering, arts and math — a program the applicants refer to as STEAM.

Over the coming months, a board-appointed committee will revise and fine-tune the Hillsboro application, which will then go before the full School Board for a final vote.