Citing the Fairfax County development boom and the need to repair aging buildings, School Superintendent Robert R. Spillane will ask the School Board this week to approve spending of a record $491.7 million by 1993 for five new schools and renovations at dozens.

At the same time, Spillane will propose widespread school boundary changes to reflect the opening next fall of five elementary schools and a new high school, and the opening the following fall of an additional elementary school. No closings are proposed for next year for any of the county's current inventory of 184 schools.

Proposed construction for fiscal 1989 to 1993 includes four elementary schools and one intermediate school and additions at eight elementary schools, most of which the board has tentatively approved but not funded.

New in this year's proposal is money to plan two more elementary schools, one additional intermediate school and one high school, all to be built after 1993. Also, Spillane proposes buying land for three additional elementary schools.

Although the sites have not been selected, the new school buildings would be in the county's southwestern "growth crescent" that stretches from Herndon to the boundaries with Loudoun and Prince William counties and to Springfield.

The renovations would include air conditioning for the 87 schools and special-education centers that do not now have it, as well as extensive work at 18 elementary schools, three intermediate schools and three high schools.

The new housing in the growth crescent will cause county school enrollment to increase from 128,000 now to more than 139,000 by 1993, officials estimate. School capacity also is being strained by new board-approved programs and smaller class sizes that require additional classrooms.

At the same time, according to school staff, many buildings that were constructed two decades ago need extensive renovations.

Spillane will present his plans to the board Thursday. The spending and boundary adjustments must go before the School Board for a vote after work sessions and public hearings. The hearing on the construction plan is scheduled for Jan. 25, with a School Board vote Jan. 28. The boundary proposals are scheduled for a Feb. 22 public hearing and a Feb. 25 vote.

Spending for new schools must be approved by county voters in bond referendums, which may be one reason the construction proposal is balanced between new buildings in growing neighborhoods and renovations in established areas.

Voters approved a $146.1 million bond referendum last year, and school officials say the wide margin shows that there is solid support for additional spending. However, some concede that they are concerned that schools must compete with another expensive county priority, new roads.

The School Board's approval last year of $196 million in new construction was threatened briefly after County Executive J. Hamilton Lambert warned that it could cost the county its cherished AAA bond rating. School and county officials worked out their differences.

The new elementary schools to open next fall, none with official names, are in Springfield, Herndon, Moneys Corner, Newington and Lorton. The elementary school to open in 1989 is in the Saratoga neighborhood. The new high school is on Braddock Road in Centreville.

Boundary changes are proposed to accommodate those schools and to adjust attendance lines between Fort Hunt and Hybla Valley elementary schools, Woodburn and Beech Tree elementary schools, Glasgow and Jackson intermediate schools, Irving and Robinson intermediate schools, and Herndon and South Lakes high schools.