The Prince William Board of County Supervisors will consider on Tuesday whether to expand the Piedmont gated community outside Haymarket, a move that could add about 260 acres and 230 single-family houses to the upscale development.

The proposal, which would enlarge the total community to 780 acres, promises the sort of high-end housing the county has been eager to attract. The additional acreage sits east and north of the current Piedmont parcel, and each single-family home would have one-half to 2.5 acres--making the density significantly lower than the comprehensive plan allows.

The developer, KSI Services of Vienna, is in contract to buy the land, formerly known as Bellwood, as it awaits the county's zoning approval. The company already has been selling houses on the main parcel with prices starting at $300,000; some houses sell for more than $1 million.

Supervisor Edgar S. Wilbourn III (R-Gainesville), in whose district the land lies, said developments such as Piedmont are part of the changing face of Prince William as the ratio of upscale housing rises and the county becomes more like its wealthier Northern Virginia neighbors.

"We struggle with our budgets and our school capacities because your starter homes are the younger families with children," Wilbourn said. "We need more balance. . . . Once our population starts maturing age-wise, we'll start matching the demographics of our surrounding communities, such as Fairfax and Alexandria."

If the expansion of the Piedmont parcel is approved after a public hearing Tuesday, it will contribute to an increasingly elite area in central and northwestern Prince William. In that area, developments such as Dominion, a gated golf community, Heritage Hunt, a retirement development, and Lake Manassas are catering to a growing segment of well-paid, high-tech workers who commute to other Northern Virginia locales.

"For decades, the heart of the working force commuted inside the Beltway," Wilbourn said. "As the jobs move out of the Beltway, then we will start to see more of the white-collar type jobs" moving to Prince William.

Supervisors have a lofty vision for an area that at one time seemed destined to become the historical theme park--Disney's America. The board has sought executive-style homes commanding high prices to produce higher tax revenue for a county that is beset by low-cost town houses and a deteriorating housing stock in its eastern end. Western Prince William has, in the last year, led the way, becoming a haven for sprawling estates amid a very suburban county.

Since the advent of the county's "Rural Crescent" plan, which reserves substantial farmland and calls for estate-size parcels, high end housing is particularly desirable to potential buyers because they know the land around them won't be built up.

KSI's application for the land, located between Route 15 and Interstate 66, promises an untouched buffer of forested land in certain locations as well as other monetary proffers. The Planning Commission approved the rezoning earlier this month.