Owners of a Silver Spring office building that exceeds county size limits are headed for a showdown with Montgomery County Planning Board Chairman Norman L. Christeller, who said he will seek to have the building's penthouse and top floor torn down.

Christeller said in an interview this week that the nearly completed, five-level office building at 801 Wayne Ave. was constructed in direct violation of county standards and must not be allowed to stand if county zoning laws are to remain effective.

He said he will appear July 26 before the county Board of Appeals to ask that the owners be forced to remove 18 feet of the 53-foot-high, $900,000 building.

"The integrity of our zoning and planing system is dependent on vigorous enforcement of our standards in a case like this," he said. "I have great faith in the process. I expect that the owner will be required to tear down the penthouse and the top floor."

Lawyers for Permanent Financial Corp., which owns the structure at the corner of Wayne and Cedar avenues, have asked the county for a variance--special permission for the building to exceed size restrictions--but Christeller predicted that the planning board would recommend against it.

Last week that panel unanimously asked the County Council to revise the zoning ordinance. The county's zoning enforcement agency, the Department of Environmental Protection (DEP), has interpreted a height restriction in such a way that would allow the Wayne Avenue building to retain the fourth floor, which is makes the building eight feet higher than the standard limit of 35 feet.

That clarification, not yet scheduled for council consideration, wouldn't directly affect the building. But Christeller said he wants to ensure that "this kind of foolishness doesn't happen again."

DEP inspectors failed to detect inconsistencies in the building plans when they were submitted more than a year ago, James M. Hicks, chief of DEP's Construction Code Enforcement, testified in earlier hearings before the appeals board. During construction, nearby residents called DEP repeatedly, concerned that the building seemed to be higher than the legal limit; according to documents associated with the case, DEP officials told them incorrectly that it wasn't.

As a result, Taro Construction Co. nearly had finished the building by the time Christeller heard about the problem and told John L. Menke, DEP director, that it not only was taller, but had more floor space than zoning laws permitted. County officials also said that the building is not set back from the bounds of public walkways. DEP on May 6 ordered Taro to stop work.

Two Silver Spring civic groups have told the appeals board they will insist that the building's penthouse and fourth floor be removed. In a June 22 decision, Appeals Board Chairman Joseph E. O'Brien Jr. allowed 15 Silver Spring residents and their attorneys to enter the case.

Joseph P. Blocher of Linnowes & Blocher, a prominent real estate law firm, said the decisions to allow the citizens to enter the case and to require the builder to get variances "complicate the case. It's another problem."

Permanent Financial has applied for zoning variances, asking the appeals board to allow dimensions that currently go beyond the standard bounds: 26 percent more floor area, a building front that extends nearly four feet forward, and an extra 18 feet in height.

Variances are granted in cases of "hardship," according to county law, but Christeller said that these cover minor discrepancies and adjustments made to accommodate the handicapped. He said "there appear to be violations" in the Wayne Avenue building "that a competent person should not have made."

DEP was negotiating in May and June to let Permanent Financial keep the top floor if the penthouse was removed. As the case opened before the appeals board last month, DEP's Hicks said the county would let the building retain its fourth floor, which would leave the structure 43 feet high. The legal limit is 35, but the law states there can be eight additional feet of "uninhabitable space."

DEP officials said they interpret office space as uninhabitable because no human resides there. But Christeller noted that he was a county council member when the zoning law was passed, and said "uninhabitable space" meant mechanical enclosures.

The planning board has asked the county council to define " 'noninhabitable' structures . . . to mean air conditioning or similar roof-top structures or mechanical appurtenances. . . ," according to the board's request.

Noting that the planning board has requested that the wording be changed, Blocher said, "Obviously, it wasn't quite clear."

He said he will press for the building variances and will contest Christeller's assertion of what "uninhabitable space" means.

Nancy M. Floreen and attorney David O. Stewart, who live near the building and are representing the 15 citizens, said they will opose any zoning variances and will attempt to hold officials to standard building limits.

In their first action as participants in the case, lawyers for the nearby residents last week asked the appeals board to order the builders to disclose more information about how they intend to prove their case. The law requires that the builder prove "exceptional or undue hardship" to get the variance and that evidence of the case be outlined so that opponents may prepare a challenge.

Citizens' attorneys attacked Blocher's disclosure that he will call seven expert witnesses and present other evidence in later proceedings. In a motion asking the board to compel Blocher to be more specific, they said his disclosure left his case "shrouded in mystery" and lacking specific information.

Blocher said he plans to meet with citizens and their lawyers, and "tell them exactly as much as we can tell them before the [appeals board] hearing on July 26."