When you make a house out of the earth itself, the building material is dirt cheap. Incorporate discards like worn-out car tires and empty aluminum beverage cans, and you can also free up landfill space and get rid of litter at little or no cost. (In fact, some tire shops will even pay you to take the tires off their hands.) Those ideas may sound economically attractive and ecologically correct, but just how nice could such a house possibly be? You'd be surprised.

You might ask noted actor Dennis Weaver, for example. His million-dollar, 10,000-square-foot home in rural Colorado, which was built this way, presents an aura of restrained grandeur. A total of 3,000 tires and 300,000 cans are encased in the walls of the two-level structure. The highly energy-efficient house is built into the side of a hill; masses of earth shield three of its four sides, retaining heat in the winter and coolness in the summer.

Or you might ask massage therapist Nancy Roux, who is building her own cozy cottage in the hills outside Mountainair, New Mexico. Athletic, but not husky by any measure, Roux used a sledge hammer to pound dirt into one tire after another, gradually building up walls out of these 400-pound, stuffed-doughnut-shaped building blocks. She calls the construction workouts "the best spa, the best gymnasium I could have wanted." As each layer of tires raised the walls higher, earth was ramped up against the building's exterior, providing a work platform and ultimately forming a temperature-moderating earth berm. After building the walls up to a height of 11 feet, Roux applied several layers of mortar to completely encase the tires and smooth the vertical surfaces. Interior surfaces can be painted or paneled, and any exposed exterior surfaces can be stuccoed.

In one of her few concessions to seek help with the construction, Roux prevailed on half a dozen friends to help her move the massive ceiling beams into position. Each wooden beam weighed between 600 and 800 pounds. After decking was laid, the roof was covered with a heavy, seamless plastic pond liner to insulate and waterproof the housetop. The exterior walls extend several inches above the roof, which is sloped to direct rainwater and melted snow toward openings that channel it into cisterns for later use as landscape irrigation.

Non-load-bearing walls like room partitions needn't be as massive as the 3-foot-thick tire walls. This is where the aluminum cans come in. They are simply laid in non-touching rows, with mortar separating them and bonding them together. A final, vertical layer of mortar creates a smooth, finished wall. Roux's accounts of her construction experience become more animated when she talks about building with cans. "It's fun," she says. "If you ever get discouraged, you can build something very quickly with cans." And in her home, those "somethings" include a sculpted fireplace, a bed platform, planters, kitchen cabinets, and even a bathtub.

Where did Roux learn how to do all of this? She started by reading a book by architect Michael Reynolds, who pioneered the Earthship concept--a house built largely of recycled trash and designed to be virtually self-sufficient in terms of energy. Earthships use photovoltaic cells to convert sunlight into electricity, which is stored in batteries and used as needed for household appliances and lighting. Sunlight pouring in through a glass wall on the building's south side admits radiant energy that is stored in the massive walls and surrounding earth. What little supplemental heating Earthships may need comes from fireplaces, wood stoves, or perhaps a propane space heater. Water is even pumped from wells with solar-generated power. Not having any utility bills (other than the telephone) was one of the main reasons Roux embraced the Earthship concept. Having been self-employed throughout her career, she will have little in the way of pensions on which to retire.

After seven years of part-time building, Roux's house still needs some finishing touches. But there's no particular rush; it's quite livable, comfortable, and attractive. Besides setting aside time for cosmetic details, Roux is also sculpting a small guest cottage to complement her one-bedroom home. Asked whether she expects to ever finish, or whether she enjoys the building process enough to just keep it going, Roux ponders a moment. "In all honesty, I would have to say I'd keep on going," she concludes. "Which is why I started the addition!"

Unless otherwise attributed, all SubsurfaceBuildings.com content is © Loretta Hall, 2000-2005.