Residents of neighborhoods along Leesburg Pike near the Dulles Toll Road say their property values have increased rather than decreased since the opening of the toll road.

Armed with lists of recent home sales in neighborhoods such as McLean Hamlet, Summerwood and Wolf Trap Woods, residents are fighting a proposal that would break the Dulles road as the barrier against westward expansion of the commercial Tysons Corner area. They are using home sales statistics to make a case for maintaining the area west of the Dulles Toll Road as residential.

For example, recent home sales prices in Wolf Trap Woods show increases of more than 6 percent, almost double the rate for most existing housing in the Northern Virginia area, residents say.

NVLand Inc., a McLean-based development company headed by Dwight Schar, is asking Fairfax County to change its land-use plan for 98 acres on the north side of the Leesburg Pike at the Dulles road interchange from residential to commercial. NVLand wants to build a 1 million-square-foot low-rise office project on the site while leaving 52 acres in open space. According to traffic figures produced by NVLand, the project could generate as many 12,000 additional car trips per day.

Fairfax County traditionally has held the Dulles road corridor as the line of demarcation between commercial development and residential areas along the congested Route 7 corridor.

Residents, attorneys for NVLand and the project architect testified before the Fairfax Planning Commission recently in what was a relatively calm session compared with previous confrontations.

NVLand's attorney, Marshall Coleman, said the land is "under the shadow of a great deal of noise" and not suitable for residential development. "Our plan would accommodate that noise by allowing low-rise commercial. It would permit a development that could tolerate the noise," he said.

Project architect Christopher J. Glaister, a member of the architecture faculty at the University of Virginia, got into a heated exchange with commission member John Thillmann over noise impact studies. Apparently, county and state studies do not agree with noise impact figures produced by NVLand.

Glaister said the noise impacts on the site make it unsuitable for low-density residential development.

"Why can you not mitigate those problems?" Thillmann asked. He said the county can require earth berms, increased insulation, tree plantings and fronting of houses away from main roads to protect homes from noise generated by cars. Thillmann said it's not like trying to protect residents from noise generated by airplanes. The county also requires a 200-foot buffer between residential construction and the Dulles road.

Glaister said that noise consultants pointed out that the current one-house-per-acre designation on the land plan "is in error. It's not good planning."

"If that is true, then we would have commercial zoning along every road in the United States," Thillmann said.

Residents said approval of the proposal would set a commercial precedent for the entire area.

"The only way to contain commercial development at Tysons Corner is to draw a line and stick to it," said Gary Edwards, a resident of the McLean Hunt Estates subdivision.

Coleman said allowing commercial development would move that line from the Dulles road to nearby Lewinsville Road, but residents said that narrow two-lane road would not stand up as a line of defense.

The Dulles Airport Access Road "is wider than the Great Wall of China. It is defendable," said Stephen Hubbard, chairman of the McLean Citizens Association's planning and zoning committee.

Pam Tsitos, a Realtor and resident of Summerwood, where prices range from $450,000 to more than $800,000, said, "The area is quite suitable for residential development.

"The need for high-quality residential development is increasing because of burgeoning growth at Tysons Corner," she said.

Victor Dunbar, representing 25 families in Odricks Corner, said his area never has been unrealistic about growth and has supported many Tysons developments but "strongly opposes this plan." Odricks Corner may be the neighborhood most hurt by construction of the toll road because it directly cut through parts of the old, historic area.

As residents living west of the toll road corridor, "we have felt secure with the Dulles road as a boundary," Dunbar said.

Resident Frances Moore said the county has supported a "green corridor from the Dulles road at least to Route 606 Baron Cameron Avenue near Reston . We need to maintain that protection." She said the developer's argument that no one would want to live on the site was not valid. "People working in Tysons II which is now under construction would be happy to locate there. We need houses. We need to raise the school population in our area because we have the space.

"Just a personal note, that land abuts three sides of my property. I expect to remain there the rest of my life," Moore said.

Representing Wolf Trap Woods, on the south side of Route 7, Jack Crosby said the 225 single-family homes in his area "are bordered by Route 7 and the Dulles road . We share exactly the same environmental impact."

"Homes average in excess of $200,000 with a significant amount of common ground. There are 200 children under the age of 10," Crosby said. He said the opening of the toll road has increased the value of homes in his neighborhood. Of the 10 sold since the toll road opened, the average sale price was $217,000. Some sales topped $230,000, he said.

A house "about 100 yards from the toll road recently sold in 10 days. This fact suggests the property could be developed residential," he said.

Coleman said the proposed office development would set aside 52 acres as green space, "assuring the commercial development would be stopped on that site. Our plan would encapsulate and put into a coccoon commercial development," Coleman said. He said traffic problems generated by the increased 12,000 cars per day could be worked out.

After a lengthy hearing, planning commission member Tybelle Fasteau questioned if she were hearing a land-use plan change proposal or a rezoning. "How does this differ from a rezoning? It blurs the line," she said.

Commission Chairman Geoge Lilly agreed. "We skated close to the line on this one."

The planning commission will study testimonies, accept written information and make a decision on the proposal later this month as part of its current review of the county's land-use plan.