Two tenant activists of the Buckingham Apartments cooperative are suing the Arlington Board of Zoning Appeals and the county's zoning administrator in what their lawyer says is an attempt to assure more housing for low- and moderate-income people if the complex wins approval to convert to condominiums.

John J. Wall, attorney for the two tenants,Susan Korfanty and John Shanley, said last week that the suit is not an effort to block the conversion of the 40-year-old apartment complex since such attempts are virtually impossible under Virginia law.

The suit seeks to shift the issue from the zoning board to the County Board by challenging the zoning board's authority to act on a request from the complex owners that would expedite the conversion of 1,422 unsold units.

Thomas J. Colucci, lawyer for the owners, the Chicago-based Stein & Co. and the Ohio-based Klingbeil Corp., said last week that the zoning board has the authority to act on the variance request under state law.

The zoning board is scheduled to hear the request at its March 7 meeting. Wall said he hopes the court will decide the question of authority before then.

Korfanty said she hopes the case will go to the County Board where Buckingham residents can lobby to require the developers to include more low- and moderate-cost units in the complex.

The units in dispute make up the bulk of the 1,800-unit complex off Glebe Road that has been converted to a cooperative over the last two years. Because of the sluggish real estate market, Colucci said, only 456 cooperative units have been sold. As a result, the two firms now want to convert the unsold units to condominiums.

The owners have requested a variance that would reduce the number of parking spaces from the 1,615 required under the current code to the 1,366 already there.

County attorney Charles Flinn said the zoning board has the authority to grant variances, but noted that he and previous county attorneys have held that any reduction in the required amount of parking spaces must be approved by the County Board.