"I'm just trying to undo the horrible damage I did as an office building designer," says Wells, 77, a tall man with self-deprecating charm. "I feel guilty for years of knocking down forests. Then it dawned on me that we can make buildings green. I think a building should disappear into the landscape as animals do. Most architects, because of their egos, don't design that way."

The Underground Art Gallery, which displays the artwork of his wife, Karen, and where Wells has his architectural office, appears embedded in a grassy bank. Steps lead down to the building's facade, a wall of floor-to-ceiling windows. In season, wisteria and grasses droop over the eaves. Inside, the light-filled space is cool in summer, cozy in winter, not the dark and dank interior that many people erroneously expect in an underground building.

To prevent leaks, the building is wrapped in a thin rubber membrane that will degrade only if exposed to petrochemicals or sunlight, says Wells. To keep humidity low -- most of the moisture in an underground building is brought in by people, he says, not leaks or condensation -- a dehumidifier is used.The building is bolstered with steel beams to hold the 100 tons of earth on the roof. That earth and 6 inches of styrofoam superinsulate the building.

Each year, Wells heats the gallery by burning just 2 cords of wood in a small stove.Wells has written more than 20 books, including The Earth-Sheltered House: An Architect's Sketchbook (distributed by Chelsea Green Publishing, 1998) and Recovering America: A More Gentle Way to Build (Chelsea Green Publishing, 1999), a picture book contrasting the built environment to natural landscapes. Malcolm Wells also paints landscapes, which are displayed at the Addison Art Gallery in Orleans.

Wells grew up in Haddonfield, New Jersey, during the Depression. He attended the Georgia Institute of Technology, then joined a Marines civil engineering training program during World War II. The war ended two years into the program, and he went on to apprentice with a New Jersey architect. During the 1950s, six-year apprentices were allowed to take the architectural exam; he passed and registered as an architect without attending architecture school, one of a very few to ever do so in the United States.

Almost immediately, he garnered a commission to design a church in New Jersey. It won an American Institute of Architecture award, and his career was launched. He started a firm that specialized in office buildings and factories. He estimates that he paved more than 50 acres of land with buildings and their surrounding asphalt.What might have been the pinnacle of his career proved a turning point: In 1964, his firm designed the RCA pavilion at the New York World's Fair, a grand structure that drew lines of visitors and even a visit by President Lyndon B. Johnson. Watching the spectacle, Wells considered the significant energy and water wasted and the landscape displaced by a building that would be bulldozed in two years.

Soon after, he visited Taliesin West, the Arizona compound of the renowned American architect Frank Lloyd Wright, where a cool underground theater provided respite from the desert climate without marring the landscape. Wells vowed that from then on, his buildings would be earth-sheltered whenever possible.With his first experiment, his second office in Cherry Hill, New Jersey, he learned that earth alone was not a good insulator and could in fact pull heat away from the building. He began insulating buildings with styrofoam, which allowed the earth to help keep out the cold but not conduct heat away from the building. When the 1970s oil crisis generated a surge of interest in low-energy buildings, Wells published a booklet called Underground Buildings, which eventually sold 100,000 copies.

The 1,200-foot gallery, which he built in 1985, originally was planned as his and Karen's home, but they ran out of money for adding living quarters. So they live in a nearby tiny shingled bungalow built in the early 1900s from a Sears-Roebuck catalog kit.Malcolm Wells lectures internationally and has produced more than 800 drawings for underground-home builders. He doesn't keep track of how many underground buildings have been constructed using his plans, but some notable examples are the Cary Arboretum in Millbrook, New York, and the offices of Construction Fasteners Inc. in Reading, Pennsylvania.

Often costing about 10 percent more than conventional construction, an earth-sheltered building reduces heating and cooling costs, resists fire, buffers outside sounds, is tornado-proof, and requires little outside maintenance. Wells designs his earth-sheltered structures with skylights, light wells, solar tubes, and south-facing windows so the buildings are filled with natural light.

Adds Wells, "Since there are plantings on the roof, there is no net loss of green area. An earth-covered building heals the scars of construction."