The Arlington County Board of Zoning Appeals has blocked plans for the conversion of 1,422 units of the massive Buckingham Apartments to condominiums.

The five-member zoning board voted unanimously late Monday night to reject a variance request from the developers, the Chicago-based Stein & Co. and the Ohio-based Klingbeil Corp., for a reduction in the number of parking spaces that would be required under the present zoning code for a conversion.

The 40-year-old complex off Glebe Road, one of the largest in Arlington, has 1,366 parking spaces, but needs 1,615 to conform with today's zoning code before a conversion can be approved. State law requires that buildings meet current zoning standards before they can become condominiums.

Thomas J. Colucci, the developers' lawyer, said yesterday he did not know if the decision would be appealed to Arlington Circuit Court.

"It was a significant victory, although it's not a final victory," said Buckingham tenant John Shanley, who had led tenant opposition to the variance. "The tenants will have to be very observant to see if there will be an appeal. It's not over by any means.

"But this shows that when a group of tenants get themselves organized, they can fight conversions . . . Maybe there still is a chance to save some affordable housing in Arlington County."

Shanley and his wife, Susan Korfanty, filed suit two weeks ago seeking to block the zoning board from considering the developers' variance request. The two contended that what the developers were actually seeking amounted to a rezoning request and not a variance. As such, they argued, the issue belonged before the County Board and not the zoning board.

The two said they hoped Buckingham tenants could then lobby the County Board to negotiate with the developers to require them to include moderate- and low-cost units in the complex. Arlington Circuit Court Judge Thomas R. Monroe ruled Friday that the zoning board could act on the request.

Over the last two years, the 1,800-unit complex has been converting to a cooperative, but only 456 units have been sold. As a result, the developers want to convert the remaining units to condominiums.