Two years ago, Loren Setlow waited in line for more than two hours to enroll his son, then in second grade, in the popular School Age Child Care program, which cares for children before and after school, at Flint Hill Elementary School in Vienna.

By the time he arrived at the signup desk, there was no room left, so Setlow tried again last year, with better luck. One son, now a fourth grader, got in last fall and his younger brother was enrolled in the Fairfax County program this September.

Setlow persevered because he thinks "the program is much better than any of the others we've seen," he said.

Parents are pounding at the doors to get into county-run child care. Eight hundred children are on the waiting list and county officials estimate another 2,500 would sign up if space were available.

The program is also available to private and parochial school children.

Some parents have even transferred their children (437 children this year) to schools outside their neighborhoods so that they could attend a school that offers day care, according to school system statistics. (Sixty-five of the county's 137 elementary schools and special education centers have the program.)

In some neighborhoods, out-of-area transfers into day care have shored up declining enrollment in the local elementary school.

The SACC program offers day care before and after school in the school building at sliding-scale fees of up to $172 a month. The program, run by the county's Office for Children, enrolls 2,230 students ages 5 to 12 at 65 elementary schools. Fees paid by parents account for $3 million of its annual $4 million budget.

To qualify, parents must be working or attending school at least 30 hours a week, or prove they are medically unable to care for their child.

The waiting list will be whittled a bit by the planned construction of day care rooms at new and existing schools in the next four years.

The School Board last week gave final approval to an agreement with the county Board of Supervisors under which the county will spend $4.5 million to add rooms at existing schools and build day care rooms at new schools. The expansion would enable 1,700 more children to enroll in School Age Child Care, but program officials concede that it will not meet the growing demand in a county where two-thirds of women work outside the home.

"What we have learned in the past is that when you open up new sites, it opens up a new waiting list," said Bonnie Arnold, SACC program director.

Just as pressure from parents is increasing, the amount of available space is declining because the county has reduced class sizes and added special programs.

Some say the county should add space by using temporary classrooms for the child care program.

That is what is being done at Flint Hill, where younger children are assigned to child care in a regular classroom and third through sixth graders in child care use a temporary wooden building a few steps away that was added this year, enabling the school to double child care enrollment, to 60 children.

Sports pennants, "Peanuts" posters and children's artwork adorn the walls. On one side of the room, children play marble football, small-table billiards and other games. On another side, an impromptu musical group -- three violins and a trumpet -- practices tunes.

Unlike the day care room in the regular building, the temporary classroom has no running water, so cleanup means carrying a bucket back and forth to the sink in the next building.

Children are allowed to leave for the bathroom only in pairs, carrying a whistle.

SACC director Arnold said she does not like temporary classrooms for that reason.

"Every time a child wants to go to the bathroom, you have to provide safety," she said. "We consider that in day care the main thing parents expect of us, and we provide for, is supervision."

But parent Susan Shipley, who has two daughters in Flint Hill day care, said the temporary classroom does not bother her.

"The kids don't seem to mind at all, and they're the ones who count," she said.

Some School Board members say they are concerned because academic classes at some schools are housed in temporary classrooms while children in day care are in permanent classrooms.

Board member Kohann Whitney said 65 temporary classrooms are used for academic classes at elementary schools that have SACC programs.

"I don't think it's fair and right," said board member Carla Yock, pointing out that the schools pay a "hidden subsidy" to the county-run day care program in utility and maintenance charges. The program pays nothing for use of the schools.

Yock said she is a fan of the day care program, but wants the county and the school system to cooperate on finding creative solutions to the space crunch, such as nearby property or sharing a room between day care and regular classes.

Arnold said the latter alternative would not work in part because day care rooms are used from 7:15 a.m. until 6:15 p.m., except for two or three hours at midday, because kindergarten children are in school only half a day for morning or afternoon sessions.

The program tries to offer a variety of activities, from sports to crafts to quiet time for schoolwork, in a home-like setting.

On one recent day, a group of younger children baked Halloween cookies while older ones played in the school gymnasium.

When Linda Weissenborn arrived from work to claim her daughter, the first grader was reluctant to leave.

She hadn't put the marshmallow and candy corn on top of her freshly baked cookie yet.

"She likes all the activities," Weissenborn said.

"She gets upset with me if I come before I am supposed to."