PAUL ANTHONY -- the face is familiar from all those television programs and commercials -- reads the want ads every week end, and visits the "open houses." "I go to see the ones that start out with 'mansion' . . ." he says.

Which helps explain why Joanne and Paul Anthony and their three children live in Boxwood House, an 11,000-square-foot house with a 20-by-30-foot drawing room, a pecky cypress library, a huge dinning room, a glassed-in office, two pantries, a servants hall, seven bedrooms on the second floor, six on the third floor, nine baths, two kitchens, a four-car garage and a 1 1/4 acres of land.

They aren't exactly living in it this minute. The Anthonys lent their house to the American Society of Interior Designers (ASID), Potomac Chapter, for its first show house, opening to the public Saturday and continuing through May 18. Proceeds will benefit the American Cancer Society's Montgomery County Unit. The house is the first on the left after turning east from Connecticut Avenue at 3815 Bradley Lane Chevy Chase. "Carol Bugg, an ASID member who lived down the street, casually mentioned about a year ago that the Society was looking for a showhouse," Anthony said the other day, as the moving men carted out their furniture."We said, 'No.' We'd seen one of the other show houses and thought it was a disaster.

"But they kept talking to us about it. Everybody thought it would be interesting to do a house, unlike all the others, where the same occupants would live in the house before and after. They agreed the house would be designed for our needs, not some mythical family."

Joanne Anthony took up the story: "Ninety-five percent of what is being done is what we would've oredered, if we had hired an interior designer. They've even kept the integrity of each area, designing for the way we use the particular rooms. And we've even asked them to talk to their neighbor decorators so the house will be in harmony."

As for why they decided to do it, Joanne Anthony said, "Because after years of waiting for the plasterer, it seemed good to have someone else take over."

The Anthonys bought the huge house in 1976, for a price in the "$200,000's, after it had been on the market for more than a year. It took almost another year of negotiation before they finially could buy it. From the time they first saw the house, they knew it was for them. "I walked into the front hall," said Anthony, "looked at the drawing room on one side and the library on the other, and said I wanted it." His wife added, "And when he saw the four car garage -- he collects cars, we have six."

"Actually," said Anthony, "we like this area because it's 10 minutes from all the television and radio stations in town." Just before this house, the Anthonys had been the losers in bidding for Ishpiming, a National Symphony Decorator's Show House, now owned by the John Threlfalls.

Boxwood was built in 1917 as a two-story summer house. In the late 1930's it grew both ways -- basement and attic were added. Paul Anthony met a couple of medical students who remember the basement being hand-dug under the house while they were bording there. Dr Oscar B. Hunter Sr., during his ownership, added a building in the rear, the beginning of the Hunter laboratory. The Anthonys use the structure as a rental cottage.

Most people, with money in their pockets, would have been tempted when they came into the handsome roundabout driveway with it inner circle of planting. We walked up to the great raised flagstone terrace, which circles half the house, and into the foyer, which is as big as most people's living rooms.

All was chaos, as the Anthonys' furniture left and workmen came to begin on the decoration.

Terri, 16, is the only one with a bedroom still intact. The parents are staying in her room while everything is being redone. They'll wake up some morning and find a canopy over their brass bed and built-in bookcases across one end of the room.

The other Anthonys, including Paul, 11, and Mark, 8, have all moved down to the thre-bedroom house they owned before they bought Boxwood. By a fluke, the house was to be empty just when Boxwood would be inhabited by designers.

Whatever non-movable changes are made by the designers will stay, free to the Anthonys if they decide to keep them. And the Anthonys can buy the furniture they like at a good price. Furthermore, some of their rent and moving expenses are being paid. So there are compensations.

When they move back in, after the show house closes, they'll find quite a different look. The Anthonys, as do all other right-thinking people, had taken down all the venetian blinds in the house painted most of the walls white and left the drawing-room windows uncluttered so they could admire their wonderful garden. The house will have a new color palette, base on purples, black and camel, and a touch of green.

The foyer, stairs and upstairs hall will have charcoal walls, with touches of carmel color, a new color scheme for the '80s, according to its designer, Mallory Lawson & associates, Inc.

The drawing room, which now has wonderfully deep windows, alternating with desplay niches, will lose two windows and three sets of shelves behind screens papered with an art. Nouveau leaf motif, according to Sarah B. Jenkins of W. & J. Sloane. The walls will be painted a soft wisteria with a Martin Seymore paint with the unlikely name of "Monk Brown."

The Flair sofas will be covered in a geometric design with pillows in a window-pane check, bith Nob Plus Non fabrics from Knoll Internatioal. It isn't legal to have a show house without Jeffery Bigelow's Lucite tables. A pair of his pedestals will sit near the entrance and back window. An Empire chaise from the Charleston Collection will give ease to the room. Indian paiintings on cloth will add an exotic touch.

The radiators will be hidden behind brass grills and a mirrored ledge.

The Anthony's handsome piano and chandelier will remain.

The other Sloane decorators on the project are C. Larry Horne, Marilyn Henderson and Erik Sandvold.

The library will be one of the more surprising rooms. Designer Antony Childs comminssioned Richard Neas of New York to paint a picture -- on the floor. Neas, who specializes in faux finishes, painted a pseudo-stone floor, right over the old one. The finish is protected by layers of polyurethene. Joanne Anthony hasn't decided if she likes it. "If I don't, I could always put a rug over it.

The Anthonys specified that no one was to do anything to the library walls, and ceiling, paneled in a pecky cypress. No one, including the Anthonys, have figured out why the ceiling slopes ever so gently toward the middle. The bowed ceiling had had many explanations, including one that suggested it was intended to be like a ship captain's cabin.

Childs is using wicker furniture in the room, but modern, chunky-looking furniture, with cushions coverd in a banana leaf print of greys and tans on duck. Quilted and padded wool slipcovers, transforms the furniture into a warm, completely upholstered look for winter. A Louis XV red-lacquer sidetable, and 18th-century chair covered in apricot leather, Chinese porcelain and leather books, a low ottoman with gilded bun feet, all will enrich the room.

Childs is adding a fake fireplace for the room, but the Anthonys plan to put in a woodstove after the show is over.

Designers John Peters Irelan and Margaret M. M. Miller have the dining room, a wonderful space that already has nteresting moldings. The fields of the panels will be filled with a Brunschwig & Fills grey-and-white trellis-patterened wallpaper with 19th-century-style fretwork. The large round table will be draped with a floor length cloth of green, pink and salmon on white. Regency chairs in a pickled faux -bamboo pattern will surround the table. A dove grey love seat will sit between the windows. And a Regency oak side table will stand under an 18th-century gilt mirror.

Six bronze dore-and-tole scones in a palm front design are on their way from France for the walls. And a pair of 19th-century blackamoore candlesticks will add to the giltter. An iron urn a faux -marble top wll hold plants.

"I want to give it a feeling of a garden room, but not too flowery," Irelan said.

Off the dining room is the office/listening room, Paul Anthony's private sanctum: Here is the second stipulation the Anthonys' made: Nothing could be done to the cabinets housing his record colection, or the new grey wall-to-wall carpeting. "After all, I'd dropped about two grand in there already," he said, "and it suits me just fine."

Designer Odette Lueck of Bowie painted the wood trim hunter green and added brass molding around all the window and door framing. The windows are left uncovered, a suitable solution to its origins as a sun room. A suede upholstered sette and crashpad floor pillows offer perches for visitors. For Anthony, there's a chair and a desk.

In the master-bedroom suite, Jeffery associates Inc. will put in a screen to back up the bed placed on the diagonal.The screen -- covered in plum, silver-grey, ivory and peach -- is both headboard and a way of making a dressing area. The walls will be plum, accented with ivory , something like the drawing room's colors. An armless rolled back sofa serves as a foot board. An ottoman pulls up to the house's second fireplace. The plum rug has stripes of the accent colors. A mirrored counter will go wall to wall beneath two of the windows to serve as a vanity.

The entrance hall to the bedroom serves as Anthony's dressing room. The closet doors will have a silk fabric inset to reflect in mirror on the other three walls. A lucite console will take up no visual room.

Other rooms and other designers having interesting ideas: Rebecca Frank, has planned the butler's pantry for plant care, drink service and banquette snacks. Jacqueline Antone will provide the mud room with a tall back bench to store boots. Ethel G. Armstrong will take on the wonderfully huge kitchen and keep the existing cabinets, while adding a hanging lighting system. Reginald Wolfe and Jo Dee Gonzalez will add a chandelier and sconces of the family dining room for informal suppers.

On the second floor: Daniel M. Webster planned the career-woman's study with a comfortable platform for reading. Walsh-McLellan already have painted a seascape graphic on the long bedroom gallery in the bachelor's wing. Carole Lindenberg designed young Paul's bedroom with a 2-foot-high platform in an "l" shape to fit the bed, with an antique traffic light and beer-can collection. John R. Miller with Donald L. Burns has planned Mark's bedroom with "built-in resistance to abuse." Keith Babcock has comminssioned a hand-painted screen with piano keys by Marueen O'Brien for the guest bedroom; cylindrical columns topped by pottery by Robert Levine will flank the bed.

G. Daniel Harbin and Linda Muha will install a stained-glass window in a bathroom. Connie Healy will use a grey flannel bulletin board in the tiny telephone booth near Terri's room, with mirror stripes to enlarge the space. In Terrihs room, William Dunn chose to build in furniture to unify the five windows and six doors. For Terri's sitting room. Marilynn Salak picked out green to enamel the walls, against coca matting, canvas Roman shades, buck-skin-covered trunk, a pine cupboard, and appliqued quilt.

On the third floor: Walter Clark will use foil paper in the back hall and bath. Sheila Kober has planned the 43-foot hall as a place for paintings:

Milo hoots and Marty Cathcart have designed the entertainment center as a place to escape for the family, though so far the boys have plans to claim it for their own. The floor will be covered with stainless steel for dancing, electronic pinball machines, computor games, platforms and pillows for lounging (or fighting). The roof angles will be painted to emphasis the jazzy look.

In contrast Lucile B. Rowe Design Associates will arrange Paul Anthony's audio studio as a quiet place for script writing and tape editing. Handpainted wall graphics will be copied from Jack Lenor Larson's High Range fabric.

Gary R. Lovejoy and Jean I. Maxwell have planned the exercise room with a rubber-tile floor and mirrors on the walls. Barbara Jan Cambell of Persimmon Tree Designs has use the existing fixtures in the upstairs bath against a contemporary design.

The best room in the house -- the immensely long basement with high ceilings and a ballroom capacity -- will be decorated after the show house is over, by the Anthonys, who already have themselves hand laid the Mexican tile floor.