When faced with uneven ground on building lots, many builders call in the excavator to bulldoze the hills into pancakes. But in the Avon Bend community near Charles Town, one house nestles into the side of a hill. Half of it is underground. Neighbors called it Duncan’s Folly, named for builder Daniel Duncan, who built the house next to his own home in 1986.

Betty Levi has called Duncan’s Folly home since 1986, when she and her husband Donald moved there from their farm in Clarke County, Va., after retiring. They bought the 2,000-square-foot rancher from Duncan, and have been its only residents. “Donald and I liked that it was unusual,” says Betty of her late husband. Now she doesn’t see the house as different.

From the front the house looks like a standard rancher. But a glance around the side of the house reveals that the house disappears into a hill. The gutters in the rear are a foot above the ground. “I’m the only person I know who has to lean down to clean out the gutters,” says Betty.

The house’s back wall is underground. The underground walls were reinforced in five different ways to reduce the risk of leaking, Duncan explains. The back and side walls were made of concrete block, reinforced with concrete-filled steel. The walls were then highly insulated before a tar and plastic barrier was installed. The reinforcements have worked; Betty hasn’t had a leak in 22 years.

The design of the home offers advantages over typical construction. Indeed the house wasn’t folly at all; it was just ahead of its time. “I knew it would be very energy efficient,” says Duncan. “I’ve been thinking green for a long time.” He recalls that at the time the government was offering tax incentives for people who built energy efficient homes.

Betty sings the praises of the energy efficient design.  For years the average electric bill, which includes electric heat, for the three-bedroom, two-bath house was a hundred dollars a month. The bill is now a bit higher due to rising energy prices, but is still a fraction of the cost to heat a standard rancher.

Despite a lack of windows in the back of the house, its interior is flooded with natural light from the many skylights on the back side of the roof.  Light streams into Betty’s kitchen and sitting area from two of them. The walls are painted white to reflect the natural light.

In this time of skyrocketing energy costs and uncertain global oil markets, Betty Levi thinks Duncan’s Folly is pretty smart.