The Fairfax County Board of Supervisors for the first time has denied a developer's request to convert rental apartments to condominiums by invoking a condominium control law amendment due to expire July 1.

The board voted 7 to 0 Monday night to reject a request by the George C. Marshall Limited Partnership to change the 343-unit Arrowhead Apartments at Rte. 7 and the Beltway into condominiums, concluding the conversion plan did not provide enough parking spaces to satisfy county zoning laws. The board also concluded it was unfair for the developer to require future condominium owners to assume the burden of maintaining 1,800 feet of private roads built in and around the premises, as had been proposed. Supervisor Joseph Alexander was absent and Marie B. Travesky abstained on the vote.

"I don't think the basic question of the health, safety and welfare of the tenants has been addressed," said supervisor James Scott, speaking for a majority of the board. "We just have to have a plan to show the adequacy of parking and . . . parking enforcement."

Arrowhead tenants and their attorney, Ira Lechner, a Democratic candidate for Congress in the 10th District, went to Monday's meeting armed with slides of pothole-scarred roads and inadequate parking at the complex, where rents range from $379 for a one-bedroom apartment to $580 for a three-bedroom town house.

"It is ridiculous to assume individual owners should bear the financial burden of maintaining excessively long roadways," said Mickie Flavin, a tenant at Arrowhead.

The board's decision followed a bitter seven-month tenant fight against the proposed conversion and brought criticism from Arrowhead attorney Jerry K. Emrich. "I don't think it's appropriate to try and put the monkey on our backs," said Emrich of the board's argument that the developer should agree to maintain a greater portion of the Arrowhead roads.

Virginia law gives local jurisdictions control over condominium conversions only in cases where an owner's plan does not meet local zoning or building code requirements, and Virginia's condominium conversion control laws are considered the weakest in the Washington area.

Fairfax County requires that an owner provide a minimum number of parking spaces for condominium onwers and an enforcement plan to ensure that larger cars will not use compact spaces, said Gilbert Knowlton, deputy zoning administrator. What's more, Knowlton said, county engineering regulations set limits on the length of roads that are privately maintained.

The supervisors decision comes just after the General Assembly passed legislation which amends the state Condominium Act to strip local authorities of some of their control over apartment conversions. The bill was introduced by Del. John Rust Jr. (R-Fairfax) at the request of condominium developers.