THE Montpelier Cultural Arts Center, well into its fourth year of operation in a good-looking barnlike structure on the spacious grounds of the Montpelier Mansion in Prince George's County, is a place of happy balances. It doesn't cost much to run, and it serves a lot of people with different needs: professional artists, artisans, poets, first-time students, tourists and community organizations of all kinds.

"We're satisfied," says Richard Zandler, a Baltimore sculptor who has been director of the center since it opened in August 1979. "We feel we're meeting our basic goals to provide broad cultural experiences for the general public and a well-structured environment for local artists. And we've become a focal point for the communities around here."

The center is located near Laurel, at 12826 Laurel-Bowie Road. Residential neighborhoods crowd in at the edges, but the setting remains bucolic. From the gates of the mansion, a fine 18th-century country home sitting cozily atop a knoll among tall trees and an elegant boxwood garden, the view of the greening forest is spectacular. The land is county-owned and comprises about 800 of the 20,000 acres that made up the original estate.

Plans for converting the Montpelier barn into an arts center date back nearly a decade. Restoration already had begun when an arsonist's fire destroyed the 50-year-old wood-frame building in 1976, leaving only a cylindrical, glazed-block silo. The state of Maryland saved the idea by providing an $880,000 grant to the Maryland-National Capital Park and Planning Commission to construct a new building on the site.

Architect Neil B. Lang of Land Design/Research Inc. of Columbia, Md., incorporated the silo into his crisp design for the new structure, which follows the footprint and duplicates the shape of the original barn with a few minor, if important, variations. Collecting panels for the building's active solar heating and cooling system distinguish the southeastern plane of its pitched roof, which is slightly higher than the original to enhance the interior spaces. The building also is a tiny bit wider and is constructed differently, using clapboard-covered concrete block walls instead of wood framing. The result is an attractive, energy-efficient, no-frills two-story building housing a variety of more or less commodious spaces--offices, private studios, shared work places, classrooms and three exhibition areas, including one squeezed into the silo's second floor. Needless to say the building is fireproof.

Anywhere from 20 to 30 painters, sculptors, photographers, potters, woodworkers and printmakers occupy studios or open work areas at a given time. Applicants are screened twice a year by an outside professional. They pay a reasonable $4 per square foot per year for the space--this adds up to $1,080 for a 15-by-18-foot studio--and can participate in the center's other programs as they see fit.

Many choose to participate. The backbone of the faculty for the center's educational program consists of resident artists. Besides standard art offerings, the list of classes usually includes a few specialties--Appalachian basketry or bronze casting or Chinese brush painting--not widely available. Fees are low, averaging about $40 plus materials for a six-week course, and Zandler says the program attracts students from the entire metropolitan area, and Baltimore, as well as nearby residents. Rental and classroom fees make up about 40 percent of the center's annual operating budget of approximately $100,000. The rest is from the MNCPPC.

There is always a variety of art on view at the center. The loft-like main gallery is reserved principally for traveling shows organized by the Baltimore Museum of Art, special juried exhibitions or invitational shows such as "Poles: Painted and Installed," the excellent effort of painter Jerry Clapsaddle that currently occupies the space. Resident artists rotate exhibits of their own works in another gallery, and additional spaces are available at modest rents to individual artists and groups.

Printmaker Judith Kornett exemplifies something of the center's spirit. She's young, serious and professional, and she uses the resources of the center in a variety of ways. "I was working for my PhD at the University of Maryland, but I was beginning to realize the main reason I stayed around was just to use the facilities," she recalls. "When I heard about this place, I jumped for it."

She shares space and presses with six or seven other artists--"Luckily we're all on different schedules, so it works out pretty well," she observes--and she has shown her work at the center. Recently she rented a gallery there for two weeks to exhibit works by students in the Annapolis junior high school where she teaches.

The center is open to the public from 10 a.m. to 5 p.m. seven days a week. It is readily accessible from the Baltimore-Washington Parkway by taking the Laurel-Bowie Route 197 exit to the north, toward Laurel.