After the last of their three sons left home, Portlanders Tom and Marilyn Deering found that they were only using half the house. "It seemed a waste," Marilyn Deering recalls. But one of their sons, Seattle Architect Thomas Deering Jr. Persuaded them to stay in their house with a redesign that married his parents' 1950s house with '80s style.

Obviously the Deerings didn't need more room. So instead of the typical add-on that extends the house, they sliced the existing house in pieces and removed the center - similar to coring an apple. What was once a small space that faced a 30-inch-wide stairwell to the downstairs family room now is a key focal point and the introduction to the three-dimensional fan shaped pattern that gives the home its geometric lines and acoustic shapes. The entry now faces a stairwell that juts up at an oblique angle like a jack-in-the-box and heads up to Marilyn's studio where she does her work as an illuminator. An alternative to the stairs is the elevator, which is designed like a European lift.

Coring out the center resulted in dramatic changes. The Deerings literally dropped their living room to the lower level. The most distinctive feature about the remodeled area is the lack of 90-degree angles, a condition the challenges the predictability of traditional design.

Sectioned and raised walls, like steps turned on their side, begin in the entry. The fluted pattern is repeated beside the stairwell and also on the three sections of straight walls

ten steel sculpture by artist Lee Kelly. Opposite the living area is a triangular-shaped gallery with only a sofa for sitting and viewing the Deerings' collection of Northwest artists.

Adjacent to the living area is the library, a room richly done in cherry wood with built-in bookshelves, a wet bar and soft lighting. The glass doors to the library are etched on both sides in elegant images by artist Howard Meeham.

The culmination of the design is an illuminated space with a dash of unexpected tension, achieved through dramatic angles and sharp contrasts between old and new. Appearing from every perspective are slivers of light, triangular shadows, and pie shaped wedges. Though the house is complex in appearance, the design is very simple according to the Deerings. "I though all the shapes and angles would drive me crazy," says Marilyn Deering, "but it's so interesting from each angle that we never tire of it."

"Thomas Deering, Jr. admits that he did not try to merge the decades in his design plan. "I didn't want to make light of the old house," he says. "But I told them, if you don't do something everywhere, you're going to feel like the old part is depressing." The 11-month project was done by contractor Lindley Morton of Green Gables Construction.

ANN WALL FRANK, a Portland Free-lance writer, contributes regularly to the Homing Instincts column. LAURIE BLACK is a free-lance photographer who lives in West Linn.