The Purcellville Town Council voted unanimously last week to audit the amount of open space that developers have provided in their subdivisions since 2000.

The move came after a new planning commissioner discovered instances in which private yards were apparently being used to fulfill the town's requirement that a certain percentage of each project be dedicated to open space. Officials also said it appeared parking lots were being counted toward Purcellville's open space requirements.

The council voted to hire an outside land-use expert to scour building plans to determine whether extra homes were in essence being squeezed into projects against town rules.

"You can't take picnic baskets to someone's front lawn," said council member Robert W. Lazaro Jr. "If you're going to use people's front yards as the open space, you're going to get more houses. It's very creative math."

So far, problems have been found in at least three developments, according to Tom Priscilla, the newly appointed planning commissioner, who said he happened across the discrepancies while looking over building plans for an ongoing development. The three developments are Courtland Square, Courts of St. Francis and The Village Case, he said.

"I have no information . . . that anyone tried to knowingly not comply with the regulations," Priscilla said. "I certainly don't want to cast any stones at anyone involved with the process to date."

Town Manager Robert W. Lohr Jr. said Purcellville will take a detailed look at the issue, including whether the town's rules were violated, whether planners missed problems in the land-use applications they were reviewing and whether the town's zoning ordinance is clear -- and strict -- enough.

A cursory review has already netted several instances at The Village Case in which yards were deemed open space by project developers, Lohr said. He declined to say whether that was a violation of the law before seeing the results of the audit.

"I just can't tell you the significance of the problem and how large it is at this point," Lohr said.

An attorney for The Village Case did not return a phone call seeking comment. But in a letter to the town, a consultant to the development, Eric E. Zicht of Zicht Engineering Ltd., addressed the questions raised by town officials. Zicht argued that the development actually provided more open space than promised.

"It looks like our open space will exceed that shown on the areas called for on the concept plan approved as part of the rezoning," he wrote. The requirement calls for open space on 20 percent of the 94-acre Village Case project, which is still under construction. Zicht said that 26 percent of the land was open space. That calculation included easements on a number of "building lots," "mini-parks" and tree-save areas, he said.

Priscilla said the project's developers had not followed generally accepted notions for what constitutes open space. "My position appears to be consistent with all our neighboring jurisdictions," he said.

Council member Robert W. Lazaro Jr.