Belle Forest residents in Fairfax County have had enough.

First the Capital Beltway sliced through the eastern border of their subdivision, located on Gallows Road. Then I-66 chopped the 1950s homes on wooded lots off from their neighbors to the north.

Now Dunn Loring Metro Station, slated to open next summer on Belle Forest's western borders, is the last straw.

Tired of encroaching development, residents are following the pattern of many other Northern Virginia communities. They have banded together to sell their homes at a higher price to a developer, NV Commercial.

"When we bought our lot and built our house 30 years ago, it was just a very rural place with farms," said Annette Herrman, spokeswoman for Belle Forest residents. "We are no longer the desirable community we were."

For NV Commercial, however, there seems to be a rosy future for office development on the Belle Forest land. President Stephen Cumbie said its location opposite a Metro station and its proximity to Tysons Corner two miles away make Belle Forest ripe for office development.

The director of Fairfax County's Economic Development Authority, April Young, agrees. Dunn Loring is the nearest Metro station to Tysons Corner and, already, development is creeping down Gallows Road from Tysons and up Gallows Road from Merrifield toward Dunn Loring. The Metro station probably will speed Dunn Loring's shift from residential to commercial use, she said.

This view is confirmed by a consultants' report just released. Market analysts Zuchelli, Hunter and Associates of Annapolis estimate that market forces would allow the Dunn Loring area to absorb between 750,000 and 1.2 million square feet of office development over the next 15 years.

Among the four Metro stations due to be operating in Fairfax County next summer, Dunn Loring's office potential is thus considered second only to Vienna's.

Consultants predict Vienna could absorb 1.5 million to 4.2 million square feet and West Falls Church 400,000 to 1.2 million. A citizens task force is recommending 400,000 square feet of commercial development for the Huntington Metro station in the Mount Vernon area.

One reason why Dunn Loring's potential is strong is that today its space is underdeveloped.

"It's a sleeper," said county planner Gary Molyneaux. While attention focuses on continued growth at Tysons Corner or Hazel/Peterson Cos.' ambitious plans for a mixed-use development at the Vienna Metro Station, the Dunn Loring/Merrifield area is quietly growing on land already zoned for high-density use, he said.

Now a popular area for low-rise warehouses, much of the area is developed at a density of 0.2 and 0.3 floor area ratio (the ratio of floor area in a building to the land area of its site). But its existing industrial zoning allows a density of 1.0, triple the existing land use, Molyneaux said, without the necessity of going through the time-consuming process of rezoning.

And redevelopment already is happening. The defense contractor TRW, for instance, has offices in Prudential Insurance Co.'s warehouse park, called Prosperity Business Campus, a 10-minute walk from Dunn Loring Metro Station. Prudential also is constructing another office building of 110,000 square feet there.

Meanwhile, the Gallows Road/Route 50 and I-495 intersection just over one mile south of the Metro station is booming.

Prudential is constructing a 1.3 million square feet commercial development in nine buildings called Willow Oaks at the western corner of Gallows Road and Route 50. On the opposite side of Route 50, Mobil Land Development Corp. is planning 400,000 square feet of offices. The Canadian partnership Cadillac Fairview has 4 million square feet of commercial development in 18 office buildings amid its mixed-use project now under construction at the eastern corner of the intersection of Route 50 and I-495 known as the Chiles tract.

These developments, coupled with the 1.2 million square feet of offices that the consultants reckon could be built around the Metro station, would give the Dunn Loring/Merrifield area half the commercial capacity that now exists at Tysons Corner.

Despite this potential, Molyneaux predicts the area will play second string to the prestigious offices at Tysons Corner. He calls it a "marvelous incubator environment" for new high-technology firms seeking easy access to Tysons and downtown Washington without having to pay high rents. Tysons Corner commands rents of $23 to $30 a square foot for offices, compared with about $18 in the Dunn Loring/Merrifield area, Molyneaux said.

Cumbie predicts that not only emerging companies will choose to locate at Dunn Loring.

"Crystal City and Pentagon defense contractors could move some of their analysts and back-office operations up the Metro line to cheaper space in Dunn Loring but still retain offices near the federal government, Cumbie said.

Banking on this theory, NV Commercial, which already owns 6.5 acres opposite the Metro station, has a contract on 17 homes on 11.7 acres in Belle Forest.

The Belle Forest homes are valued between $102,000 and $120,000. Neither residents nor Cumbie would reveal how much homeowners might gain under the contract with NV Commercial, but commercial land is selling in the area for between $10 and $20 a square foot. The exact amount residents would receive depends upon the density of zoning the county allows.

NV Commercial is seeking a planned development commercial zoning but must get an amendment to the comprehensive plan, the county's blueprint for future development. Cumbie said the proposal he will unveil to county planners June 24 shows a mixed development, 80 percent of which will be for commercial use and 20 percent for mid-rise residential units with a density probably exceeding 1.0 FAR.

County planners are delaying action on the plan amendment and rezoning application until next spring, when a citizens task force is expected to present its recommendations for future development around the Dunn Loring Metro site.

Though commercial prospects look good for revitalizing the Dunn Loring area, consultants Zuchelli Hunter and Associates point out in their report that the area has limitations. There is no direct access from Interstates 66 and 495 to the Dunn Loring Metro site. It relies on Gallows Road.

Road capacity in the area, however, is good. A study by the Washington Metropolitan Council of Governments shows that planned road improvements in the vicinity of the Dunn Loring Metro Station would give it the capacity to absorb at least four times more traffic than currently is there.

Image-conscious companies also could locate their buildings alongside interstate highways at the Dunn Loring Metro area, the consultants point out.

Belle Forest residents, meanwhile, hope this adds up to the county agreeing to high-density development around the Metro site so they can get a good price for their homes.

"It isn't that we are out to get rich. That's the furthest thing from our minds," Herrman said. Feeling pushed out by development, she just wants enough money to move to a quieter residential neighborhood once more to enjoy her retirement.