What happens to a 20-year-old school building once officials decide that it should be closed? In too many instances, the building stands vacant and is vandalized. But some imaginative residents of Arlington, working together with county officials, came up with a better solution: a community center. That's how Gunston Junion High School, a large, rambling building located at the corner of Glebe and Arlington Ridge roads, became the "Gunston Community Complex." It will have its official opening on Friday.

The center houses, first of all, the Gunston Recreation Center, with three gymnasiums, several playing fields and tennis courts. The recreation center also includes a nutrition center, where older residents can receive a hot lunch during the week, and the Adult Continuing, Vocation and Career Education Center, which offers classes in English, arithmetic and other basic skills as well as instruction in everything from needlepoint to auto repair.

But to us, we confess, the art center is the most exciting. There's 650-seat auditorium, rehearsal studios for vocal and instrumental music and a costume shop. A new dance studio has been included, along with offices, a library area and conference space. What's more, the arts center has several resident companies, including the Arlington Dance Theatre, the Children's Theatre of Arlington, the Farlington Players and the Arlington Players, which not only perform there but also travel around the country offering productions.

The upcoming weekend of festivities includes such things as an ethnic-food festival, a barbershop-quartet concert, group dancing and performances by some of the resident companies.We can't think of a better way to use a surplus school.