With dozens of courthouse employees in cramped, temporary offices because of a recent fire there, Arlington County Board members early today approved a plan to hold a bond referendum on a new police and courts facility two years ahead of schedule.

Under a $331.6 million, six-year capital improvement program approved by the board, County Manager Anton S. Gardner's proposal for a new courthouse will be put before Arlington voters this fall, rather than in November 1992 as originally planned.

The board tentatively endorsed a $91.9 million county and school bond package for this fall that would include $54.4 million for the police and courts facility, which would be built near North 14th Street and Court House Road, across from the current courthouse.

Also included in the bond proposal would be $23 million for school improvements and maintenance, $11.1 million for road and neighborhood improvements, $4 million for parks programs, and $2.5 million to help pay for a fire station. The County Board will determine the exact amount of each bond proposal in August.

Last night, Gardner told the board that the May 20 fire that destroyed the fourth floor of the seven-story courthouse had accelerated the need to replace the 30-year-old structure, which Gardner called too costly to renovate because it contains asbestos and has other problems.

"It's a really deplorable situation," Commonwealth's Attorney Helen Fahey told the board, noting that because of the fire, "we have the use of only half the courtrooms."

Board member William T. Newman Jr. agreed, calling the courthouse "the worst in Northern Virginia in many ways."

To make room for the courthouse proposal on this year's ballot, board members agreed to rearrange funding plans for several proposals, including a $50 million rehabilitation and expansion of Arlington's waste water treatment plant. Officials initially planned to split the costs of the work between bond proposals this year and in 1994, but instead will seek to fund most of it in a 1992 bond package.

The six-year spending plan reflects a move toward using long-term bonds rather than yearly revenue to pay for major improvements, county finance officials said. An $82 million bond package is tentatively set to go before voters in 1992; a $34 million plan is scheduled for 1994.

Bonds are proposed to finance about 63 percent of the new plan, which covers fiscal years 1991-96. Last year's plan for 1990-95 proposed that bonds finance 53 percent of improvements.

Board members last night also agreed to hold a public hearing on whether to change development guidelines for a 40-year-old Ballston apartment complex whose low- and middle-income residents are worried that high-rise development will force them to leave their homes.

Residents of the Pollard Gardens apartments, whose 124 units are home to low- and middle-income workers and senior citizens, many of them Hispanic and Asian immigrants, are pushing for a change in the county's General Land Use Plan to discourage high-rise buildings on the site bounded by North Fairfax Drive, Wilson Boulevard and North Pollard Street.

Because the land use plan is only a development guideline, county officials say they are unsure whether changing the plan would prevent the complex's owner, Premier Realty Co., from tearing down the complex. If the land use plan is changed, Premier probably still could replace the complex with town houses or similar residential units.

Still, officials have said that the residents' effort to change the development guidelines before any new construction has been proposed represents a new strategy to try to save the county's shrinking supply of low-cost housing.