Historic sites and homes dot the landscape in Northern Virginia, from Quaker farms in western Loudoun to the Victorian-era downtown of Manassas, and with development creeping westward, preservationists in the outer counties are beginning to look into ways to protect their historic resources.

Particular pressure has been felt by the towns and small cities, the business centers of rural and suburban Virginia where historic properties often are threatened by commercial redevelopment. And preservationists, many hoping to increase property values by slowing or controlling growth in their communities, are finding those pressures can be tough to fight.

In Manassas, a city rich in Civil War history, preservationists have been working now for years to get a historic district adopted by the city council, and city staffers say an ordinance could be in place in a few months.

But it is unlikely to include the sweeping protections preservationists sought as a way of shielding their downtown from the urban sprawl creeping westward from Fairfax County.

"It's a controversial subject," said Randy Hobson, director of planning and zoning administration for the city. "The original proposal was for a district to include 365 acres of the downtown, but they the city council may cut it back."

Hobson would not say what other changes might be made to the proposed ordinance, but said they probably would be less restrictive than preservationists wanted, largely because of resistance from members of the business community concerned about giving up their rights to alter buildings in the district.

A few miles away in Reston, preservationists are making similar efforts, asking the Fairfax County Board of Supervisors to adopt a historic district for one of their local sites, a move initiated after a retailer attempted to make design changes in the building's facade.

But it's not an historic site they want to preserve, but an architectural site. Residents in the 20-year-old planned community want to preserve Lake Anne Plaza, a lakeside shopping area that proponents call a "shrine to planned development," in hopes of preventing architectural changes to the commercial and residential center, said Fairfax County Supervisor Martha V. Pennino, who represents Reston and has supported the proposal.

County staffers said that, if Lake Anne Plaza gets the historic designation, a county architectural review board will have to approve any changes to the outside of the center.

While Reston residents have considered the idea of an historic district for Lake Anne Plaza before, efforts were rekindled recently after Southland Corp. tried to get design changes in the structure to open a 7-Eleven outlet. Those changes were denied by the County Board of Supervisors after citizens and other retailers in the shopping center launched a massive protest.

"Lake Anne Plaza is not ancient history we are trying to preserve, it's modern history," said Pennino. "It is necessary to do this now that the plaza has been sold as condominiums, to make sure future owners do not change the facade or hang big signs out in front."

Elizabeth David, Fairfax County's historic preservation planner, said she has no problem with the proposal and would be forwarding it to the Board of Supervisors soon. But she said that she doubts that LakeAnne would be included in the Virginia State and National Historic Registers, even with local designation.

"The problem will be in Richmond, because the state commission has said a site must be at least 50 years old," said David. "There won't be any tax benefits for them," unless they are included on the state and national lists, she added.

For income-producing properties on the National Register of Historic Places, there are some federal tax benefits. Owners can take 25 percent of the funds used in rehabilitating an historic site as a tax credit so long as the total amount spent was a substantial investment, generally considered as equal to or greater than the value of the building before the rehabilitation.

It often takes years to get a historic district or site approved for the historic register, and preservation specialists say a local historic designation often can provide more protection against changes to the property than inclusion on the list, which does not prohibit the owner of the building from doing whatever he wants, even if that means demolition.

"For some of these small towns, the greatest thing they have is their historic resource," said Elizabeth Watson, a rural project field representative with the National Trust for Historic Preservation. "If you destroy that, it's like destroying their identity, and they lose a part of what makes them most marketable."

Despite the obvious advantage of the federal tax credit for nationally recognized historic districts, most small communities pursue historic status to bring the power to control change into the hands of the town, usually in an effort to slow decay or to encourage upgrading of public and private properties, Watson said.

The town of Round Hill in western Loudoun County is only four blocks big, but there's a shady-tree, white-clapboard quaintness to the community that residents would like to see preserved.

So they were surprised and angered three years ago when one of the towns oldest homes was demolished by its owner, and they formed a committee to look into making an historic district out of the sleepy town.

"It seemed like one day the house was there and the next day it wasn't," said Round Hill Mayor Jeffrey Wolford. "We had no control over it, and that upset people."

But now, with other problems keeping town leaders busy, the preservation of Round Hill has been put on hold indefinitely, although Wolford said that a specific ordinance probably will be proposed to the town council in the future.

In historic Loudoun County, where tourism ranks second only to agriculture for bringing in revenues, many of the small communities have adopted ordinances protecting their historic downtowns. Leesburg, which adopted an ordinance in 1963 and was one of the first Virginia towns to do so, Waterford, and Middleburg are nationally known tourist attractions, but in Loudoun even places as small as Aldie and Hillsboro have followed suit.

"The indication was that real estate values would increase over time by preserving the historic village," said Alexander Muir, mayor of the 115-person town. "And I think there was the issue of prestige involved. We're not in the same class as Waterford or Middleburg, but we have lots of pre-Civil War houses and have restored an old school house."

Hillsboro has only been an historic district for three years, and Muir said he does not the designation has had any effect on real estate values, but he believes that it will.

"There is well-documented proof that there are benefits for a community that makes an effort to preserve its historic resources," said Watson. "Historic resources are finite, and the effort often brings the community together."

In Manassas, however, that has not happened. Hobson, the town planner, said that the preservation struggle has divided the community and that the controversy may intensify again when the proposal is taken up by the city council.

"There are some people that say the city isn't even historic," said Manassas planner Hobson. "I guess it's all in the eye of the beholder."