Ten years ago, a ho-hum Arlington student lobbied his high school to offer a serious, full-year filmmaking course. His school heard him. This January, that singleminded young man won the prestigious Sundance Film Festival director’s award. Cutter Hodierne , a 2005 graduate of Arlington’s H-B Woodlawn Secondary, won the prize for “Fishing Without Nets,” a gripping feature about Somali pirates produced with his friend and fellow H-B graduate, Raphael Swann.

“That course was one of the most important things that has happened in my entire life,” said Hodierne, now 27, who lobbied for the course in H-B’s ultra-democratic Town Meeting, where students and staff vote on everything from course offerings to teacher hires. He added that he is typical of “all the kids that are just on the edge with some kind of intelligence that’s not going to come out in a traditional school but that’s gonna be completely nurtured at a place like H-B.”

Hodierne and hundreds of other H-B alumni, students, faculty and parents are increasingly alarmed by school board proposals that could snuff out one of the brightest lights in Arlington County’s excellent school system. Created 40 years ago as a student-driven alternative to traditional schools, the sixth- to 12th-grade program has become the most sought-after lottery school in the county.

At H-B there are no bells, no hall passes and no courtesy titles; teachers and students are on a first-name basis to foster a sense of partnership. Students are expected to take ownership of their academics, and they rise to the occasion: The program repeatedly scores at or near the top of Post education columnist Jay Mathews’s local Challenge Index, which measures the number of college-level tests given at high schools, per capita. Teachers do double-duty as counselors, strengthening trust between themselves and students and eliminating a layer of administration. It’s hard to fall through the cracks at H-B. Its graduation rate — with the exception of those in a program for non-English speakers – is typically 100 percent.

But the program is at serious risk. Faced with a countywide student population that is growing by more than 700 every year, the school board is considering a proposal to double the size of H-B — or to move it to an unidentified, leased commercial space, replacing the current campus in northeast Arlington with a mega-middle school. “The idea of a leased space feels like a slippery slope to oblivion to a lot of alumni and students,” Mary Byrne, parent of an H-B senior, told John Chadwick, the board’s lead staffer on school capacity, at a recent, packed community meeting in the school cafeteria.

At the same meeting, Chadwick acknowledged that the staff-student intimacy that undergirds the program could not be maintained if the number of students is doubled. H-B’s success is utterly dependent on the school’s small size: 503 lottery students from all over the county, plus a combined 145 students in programs for new immigrants, students with Asperger’s syndrome and severely disabled students.

The hunger among Arlington parents for small schools is obvious: Two months ago, 405 students entered the lottery for 69 sixth-grade spots at H-B; 155 tried for one of the 10 ninth-grade spots that were available. The academic literature supports their parents’ enthusiasm, as groups such as the Bill and Melinda Gates Foundation have recognized. The National Research Council reports that small schools foster a feeling of “connectedness,” which in turn protects teens against an array of dangerous behaviors, according to the Centers for Disease Control and Prevention. And students at small public high schools — especially poor and minority kids — do better academically than their large-school peers, according to many studies.

Ask H-B alums about the benefits. While preparing this article, I sent out an e-mail asking to hear from former students who felt that H-B made a vital difference in their confidence, careers and commitments as citizens. I heard from dozens, including the senior producer of Vogue; a radiology resident at Walter Reed Army Medical Center; a one-time dancer for the Washington Ballet who is now a marine biologist; and a naval surface warfare officer who later morphed into a research assistant for writer Gore Vidal. Virtually all felt that H-B’s small size was crucial to the gifts it gave them.

“H-B Woodlawn saved me,” says Matt Smith, chief executive of SmithGifford Communications, one of Washington’s top advertising agencies. Smith was on the point of dropping out of Yorktown High School but instead transferred to H-B in 1975. Today, still influenced by H-B, he keeps his business small. For his success, he says, “I give credit to the small, intimate relationships I formed with the staff and students in just one year at H-B. For some people, small is good.”

As the parent of an H-B ninth-grader and an eighth-grader who attends a huge Arlington middle school, I know no one doubts that the land-starved Arlington school system is facing a capacity crisis. The school board has to act. But in a wealthy county with school leaders richly endowed with brains, expertise and creativity, surely the solution is not to damage a program that is hugely successful and desperately in demand. The school board can, and should, find a way to hatch multiple, H-B-size schools, following a model that has so demonstrably worked.

The writer is a fellow at the New America Foundation.