The Loudoun County Board of Supervisors voted Tuesday to pass along millions in new state funds to schools and approved construction of hundreds of new homes in South Riding, two moves that underscore the continued development pressures facing the nation's fastest-growing county.

The supervisors also voted to lift a hiring freeze first put in place last year by County Administrator Kirby M. Bowers as a money-saving measure; to study privatizing operation of the county jail and maintenance of Loudoun's parks; and to reconsider the criteria for exempting such organizations as the Howard Hughes Medical Institute from local taxes.

Attorney General Jerry W. Kilgore issued an opinion last week, in response to a request from the board, saying that supervisors have the authority to revoke tax exemptions they give out. The issue has been spearheaded by Supervisor Lori L. Waters (R-Broad Run), who criticized a decision by the former board last year to give the nonprofit research organization nearly $6 million in annual tax breaks. Waters would not say whether she would try to revoke that exemption.

The board's six-member Republican majority -- members who pledged during their campaigns to overhaul how Loudoun manages its finances -- also promised at Tuesday's board meeting to reveal details soon about plans to appoint a commission to undertake a broader, and more ambitious, examination of county spending. That could include looking at whether entire government departments, such as planning and public information, should be farmed out to the private sector.

The developments show that although this year's contentious budget season is coming to a close, supervisors are moving to reopen many of the most difficult questions the county faces as breakneck population growth continues to spur demand for schools and other expensive services.

The board turned back a challenge from three Republican supervisors by voting Tuesday to transfer to the public schools the full $6.8 million in additional education funds the county expects to receive from Richmond as a result of the state legislature's budget compromise.

The decision leaves the school board $7.2 million short of its $476 million spending request, a comparatively rosy state of affairs that brought public thanks from school officials, who had voiced concerns about how they would make up what had been a $14 million shortfall.

Supervisors Eugene A. Delgaudio (R-Sterling), D.M. "Mick" Staton Jr. (R-Sugarland Run) and Waters tried to slice $3 million from the county's transfer to the schools, but that motion failed. The vote on the full transfer passed 7 to 2, with Staton and Delgaudio opposed.

The GOP supervisors also voted to change the zoning on 194 acres owned by Toll Bros., a Pennsylvania-based home builder, to allow 620 homes to be built south of Dulles International Airport. Much of the land had been zoned for industrial uses.

Many South Riding residents objected to the idea of industrial development near their homes and supported the housing proposal, while others argued that changing the zoning to allow a mixture of homes, stores and offices would be better for the long-term development of an area that lacks retail and other services.

Board Chairman Scott K. York (I-At Large) said taxpayers were being saddled with millions in additional costs because the board majority refused to hold Toll Bros. to county standards, adopted last year, that outline how much builders should pay to offset some of the costs associated with their projects.

"The people who will have to pay for this community will be the taxpayers," York said.

Proponents of the rezoning said Toll has agreed to give the county $11.6 million in cash for capital facilities and a 20-acre school site, among other things. Supervisor Bruce E. Tulloch (R-Potomac), who campaigned on his opposition to converting industrial land to residential land, said he and local residents believe the land in question had been "improperly zoned" years ago.

"I reserve the right to become better educated" on such questions, Tulloch said, adding that Toll Bros. was making a large donation to finance the construction of a community center that he said would benefit old and new South Riding residents alike.