Interview with an Environmental Architect

To Michael Reynolds, a house is not just a home, and old tires and empty soda cans are not just trash. For almost 30 years, this Taos, New Mexico, architect has been designing and building energy-efficient houses out of automobile tires, cans, and other discarded items. These houses, which Reynolds now calls “Earthships,” not only provide a comfortable, affordable place for people to live but also contribute to a sustainable future for our planet.

The Origin of the Earthship Design
In 1970, a TV report about the growing number of beverage cans littering the streets and fields of the United States started Reynolds thinking about ways in which trash could be used to build houses. Through many years of experimentation, he found that sturdy walls could be built by packing soil into old tires, stacking the tires like bricks, and covering them with cement or adobe, a heavy clay often used in buildings in the Southwest. Reynolds had this design tested by structural engineers to ensure that the walls would meet or surpass any existing building code requirements. One engineer even commented that the design could be used to construct dams!

Building an Earthship
The tire-stack design is used for three of the outside walls of an Earthship. These walls are approximately 1 m (3 ft) thick, and this large mass causes the walls to act as a battery, storing energy from the sun and releasing the energy when needed. The base of the Earthship is built below the frost line (the deepest level to which the ground freezes). Below this line, the ground maintains a constant temperature— around 15ºC (59ºF)—and walls anchored below the frost line usually stay at that temperature too. The fourth wall, which faces south, is constructed completely of glass to capture as much sunlight as possible. In the winter, the tire-stack walls hold in the sun’s warmth. In the summer, cool air enters through windows in the front while warm air escapes through a skylight in the back.

Even the soil that is excavated for the site of the house is used to build the house. Some of the soil is pounded into the tires to construct the walls, and the remaining soil is piled against the outside of these walls and on top of the roof (constructed of beams) for further insulation. The most suitable location for this design is a south-facing slope of a hill, where the Earthship can simply be built into the hill. Often, Earthships look more like natural formations of land than houses. Inside the house, walls between rooms are constructed by embedding empty beverage cans into mortar or mud. When these walls are covered with cement and then painted with latex paint or some other durable finish, they look just like walls constructed with conventional materials. Other inside surfaces, including stairs and even bathtubs, can be built using the beverage-can technique. Because the cans are so lightweight, this method can even be used to create dramatic interior structures such as arches and domes.

The Environmental Impact of the Earthship Design
Earthships are typically built to obtain electricity from photovoltaic cells that convert sunlight to electricity. All household water is supplied by rainwater that is collected on the roof. Wastewater from sinks, tubs, and the laundry room is recycled to nourish plants in the greenhouse, which can provide a sustainable source of food. With these features, people who live in Earthships use fewer of the Earth’s resources and often have no utility bills. Because Earthships are environmentally friendly and inexpensive to buy and maintain, more and more people are choosing them instead of conventional homes. Earthships now exist in almost every state and in many countries around the world, including Canada, Mexico, Bolivia, and Japan. Wetter environments simply require that the house is built entirely above the ground and uses more cans and tires.

More tires in the design certainly wouldn’t be …a …problem. According to the Environmental Protection Agency, more than 250 million tires are discarded in the United States every year. But most landfills do not accept tires because of their tendency to rise to the surface even when the landfill is covered over. Tire dealers usually pay to have used tires hauled away to stockpile areas, where they sit indefinitely. Earthships provide one way to diminish the stockpiles.

Michael enthusiastically shares his Earthship concept with others. To Michael, an Earthship is not just a home—it’s a lifestyle. His dedication to designing Earth-friendly homes is a result of his commitment to “reducing the stress involved in living on the Earth, for both humans and the planet.”

More to Explore

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