At least 274 of Loudoun's 3,310 teachers and guidance counselors will change schools next year, 175 of them involuntarily. Some schools will lose 20 percent or more of their faculty to other schools.

School officials released the statistics this week at the request of School Board members, who are discussing whether to cap the percentage of a school's teachers who can move in any one year.

The numbers reflect only the first of three rounds in the teacher transfer process and are likely to rise. In the first round, teachers can apply to move to any county school, and principals can hire from among those who have expressed interest in their school. The school system tells other teachers that they must move to accommodate shifting student enrollment.

Administrators and teachers said rapid growth and school construction in Loudoun means that teachers move from school to school frequently.

But School Board member J. Warren Geurin (Sterling) is pushing for a transfer cap and a rule that would prohibit principals who are changing schools from recruiting teachers to join them. He said the numbers reinforce his belief that the current process allows too many teachers to leave a school.

Geurin was reprimanded by the School Board in January. Members would not give a reason, but sources have said teachers at Sterling Elementary School complained that he pressured them to stay at the school, rather than move to the new Countryside Elementary School with their principal.

According to the statistics, nine Sterling teachers have requested and were granted transfers, meaning almost 21 percent of the school's teachers are already scheduled to leave. The figures do not show where the teachers were moved.

"It seems to me that makes the job of being a school principal, at a school where you're replacing a longtime principal or a beloved principal, more difficult than necessary," Geurin said.

Geurin said he was also upset that 10 of Sugarland Elementary School's 47 teachers have been transferred in the first round. Sugarland Principal Lisbeth V. Fye will open Frances Hazel Reid, the new Leesburg elementary school, in August.

Hamilton Elementary School will lose at least nine of its 28 teachers, the figures show. Principal Carol A. Thomson is leaving to open Purcellville's Mountain View Elementary.

At the high school level, Broad Run will lose at least 12 of its 127 teachers, and Stone Bridge will lose at least 11 of 124. Park View and Potomac Falls high schools will lose students to the new Dominion High School. Twenty-three teachers are scheduled to leave Potomac Falls, and 12 will leave Park View, seven at their own request. In all, 33 of Park View's 137 teachers had sought a move.

Matthew D. Britt IV, assistant superintendent for personnel and the school official in charge of the transfer process, said it was not unusual or problematic for a Loudoun school to lose 20 percent of its faculty to transfers.

The county opens three to five schools each year and is committed to staffing them with a mix of experienced Loudoun teachers and recruits from outside the county. Moves are also necessary, he said, when a crowded school loses children to a new school opening nearby. "We're not alarmed at those percentages," he said.

The numbers also show that more than 5 percent of Loudoun's teachers will be involuntarily transferred next year. At some schools, teachers who requested a move did not receive one while other teachers were moved.

Britt said involuntary moves come with a fast-growing system. Teachers who volunteer to move do not always work in the subject areas or grade levels in which new teachers are needed. Budget cuts, which reduce the number of positions available at some schools, also do not help, he said.

"We have to put teachers in places where we need them to ensure they have employment," he said.

Teachers unhappy with their placements can reapply for specific vacancies during the second transfer round going on now, he said.

A third transfer round, offered for the first time this year, will allow teachers who have been moved involuntarily to reapply for positions at their original schools if they become available.

Loudoun Education Association President Claire Scholz said that the number of involuntary transfers seemed high and that the issue required more study.

At Eagle Ridge Middle School, which is losing about 60 percent of its students to a new school, only 14 of 66 teachers who requested a move were granted one. At the same time, 36 teachers were moved involuntarily.

"They're taking huge destaffing cuts, and there's every appearance that they could have been able to accommodate more of the voluntary requests," she said. "We need to do more looking."