Six of the nine seats on the Loudoun County School Board will change in January, after three incumbents were defeated Tuesday in local elections.

Incumbents Wendall T. Fisher (At Large), Jeffrey M. Maged (Leesburg) and Susan N. Hembach (Broad Run) lost bids to retain their seats on the board that governs Virginia's fastest-growing school district. Three other current board members opted not to run for another term, marking a drastic change in the makeup of the board.

Also on Tuesday, a $100-million school bond referendum overwhelmingly won the backing of voters, paving the way for construction of four new campuses and an expansion to Lucketts Elementary School. But a $5.3-million addition to the school district's administrative offices on North Street was soundly rejected.

The turnaround on the board came after a relatively quiet campaign season. Incumbents and challengers agreed on the need to raise teacher salaries, build more schools to handle the burgeoning student enrollment and reduce class sizes. But several of the challengers argued that improvements in those areas should be made by cutting costs in others.

John A. Andrews II, president of the Loudoun chapter of the Northern Virginia Building Industry Association, won the most contested race for School Board, beating two other candidates to represent the populous Broad Run area.

Andrews, who raised more money--much of it from developers and real estate agents--than any other candidate, beat incumbent Hembach, who was appointed to the board to fill a vacancy in June, and Michele N. Zuckerman, an active parent volunteer who is president of the Horizon Elementary School PTA.

Andrews said his interest in shaving school construction costs and his business experience appealed to voters in the rapidly growing county. "I think I have a different expertise than other people on the board," said Andrews, 38.

Frederick F. Flemming, who served as a board member from 1989 to 1993, will return to the board after ousting Maged in the Leesburg district. Flemming spent less than $1,500 of his own money on the campaign and said he mailed campaign checks back to would-be contributors because he didn't want to take anyone's money. He attributed his success to campaigning door-to-door to about 1,870 homes.

"I'm delighted and really pleased about getting back on the board," said Flemming, 73, a retired college professor.

Thomas E. "Tom" Reed, a systems consultant who won the endorsement of the Republican Party and received $2,250 in campaign contributions from local GOP groups, beat incumbent Fisher easily. Reed, 43, was the most conservative candidate and has voiced support for vouchers, a practice of using public funds to allow students to attend private or parochial schools.

Neither Reed nor Fisher could not be reached for comment Wednesday.

Candyce P. "Candy" Cassell (Sugarland Run), was the only incumbent to survive a challenge. She beat Edward L. "Lee" Ostrander by nearly 250 votes, according to unofficial tallies. Cassell, 46, is an administrator at a law firm.

Patrick F. Chorpenning Jr., a Fairfax County teacher, beat Dean W. Coursen, who owns a landscaping company, for the Mercer District seat by nearly 300 votes, unofficial results show. Chorpenning, 31, will replace Edward J. Kiley, who decided not to seek reelection.

Four candidates ran unopposed: incumbents Joseph W. Vogric (Dulles), the chairman, and Harry F. Holsinger (Blue Ridge), the vice chairman, and newcomers Geary M. Higgins (Catoctin) and J. Warren Geurin (Sterling). Vogric, 46, is a business executive and Holsinger, 63, is a retired high school principal. Higgins, 46, is the labor relations director for the National Electrical Contractors Association, and Geurin, 53, is a technical writer and consultant.

This was the first year that the local Republican Party endorsed a slate of candidates for the School Board. The election of Reed, combined with new members Higgins and Geurin, could signal a conservative coalition of members on a board that has no particular factions.

Vogric played down potential conflicts among board members, saying only, "It should be interesting."

School officials said they weren't surprised that the North Street expansion project was rebuffed by voters. Office space for administrators is a tough sell in a county that needs 22 new schools in the next six years, Vogric and Superintendent Edgar B. Hatrick III said.

Portable trailers may be installed on the parking lot in the next year to create more office space, Hatrick said, adding that the project could be placed on next year's ballot to seek voter approval once again.

"Clearly what we need to do is make our case better to the citizens of Loudoun County," he said.

Voters narrowly defeated a $7.6-million referendum to build several ballfields and two aquatic centers on new school sites that would have been owned by the school district and operated by the county parks department. Dale Polen Myers, chairman of the Board of Supervisors who lost her reelection bid Tuesday, said she was disappointed that the shared recreation centers were struck down at the polls.

"You had the opportunity to save money and build . . . facilities and that will not happen now in Loudoun County," she said.