If blueprints for a new hotel showed a lobby, restaurant and swimming pool but no guest rooms, the builder would surely send the architect back to the drawing board. Unless, of course, the architect were an eight-year-old taking the anything-goes "Blueprint for Building" class, one of the Corcoran School's fall studio workshops for children.

Two five-week series of drawing, painting and sculpture classes are taught from the ground up in a stark white basement workroom looking huge and high-tech: concrete columns, frosted skylight, marble floor and long tables. There the young artists are free to splatter, shriek and spill.

"We try to make children see things first and make them aware of what's around them," says Karen Worth, one of four workshop teachers.

The museum's collection of bright, bold contemporary canvases can help develop the students' sense of color; the current "Northern Light" exhibit of 19th-century Nordic paintings shows them something about mood, and the Grand Salon from the Hotel D'Orsay brings shape to life. A gallery tour gives them "an awareness that allows them to make more use of their imagination," Worth says.

"Although there are techniques you can learn that are right and wrong -- a certain way to use pastel or to hold a pen," she adds, "our main goal is draw out each child's creativity. I try to do a lot of games, storytelling, scavenger hunts, acting -- anything to make the paintings seem more real -- not just something untouchable on the wall."

In Worth's "Art Comes to Life," an hour- long class for children four to seven that begins this weekend, a child turns the formal portraits inside out by drawing the robust figure of Ben Franklin and poking his own head through the painting.

The dramatic gold-leaf paintings that tell the story of Joan of Arc inspire "Phantoms and Phaeries," a drawing and creative-costume class that begins in November. No role reversal here -- whenever the course is offered, the boys still hammer out cardboard shields and swords while the girls go for muslin ladies-in-waiting get-ups. No one has yet aspired to be the heroic but tragic Joan. ART FOR FUN CORCORAN SCHOOL FALL STUDIO WORKSHOPS, in the Corcoran Gallery, 17th and E streets NW; 638- 3211. The first five-week session -- "Kaleidoscope of Seasons," "Art Comes to Life," "Drawing Diary," "Drawing" and "Sculpture" -- begins Saturday and continues through October 31. The second series of workshops -- "Phantoms and Phaeries," "Impressions of Color," "Young Artist's Sketchbook," "Blueprint for Building" and "Printmaking Studio" -- runs November 6 to December 5. Classes are held Saturdays and Sundays. The fee is $46 for children four to seven and $58 for children eight to 11.