By Maggie Romuld

Roswell, New Mexico, may be famous for spaceships, but Taos, New Mexico, is best known for its "Earthships," passive solar homes conceived by architect-turned -"biotect," Mike Reynolds, almost four decades ago in response to the environmental issues of the time. In an interview with Wendy Jewell (www.myhero.com), Reynolds said he created the word "Biotecture" to describe, "The profession of designing buildings and environments with consideration for their sustainability, and he described Earthships as, "Fully sustainable buildings made with the by-products of society."

Earthships are designed to be built of natural and recycled materials that can vary according to what is locally plentiful (including tires, bottles and recycled cans) and what is most appropriate for a particular climate. The first Earthships built in New Mexico typically had "exterior walls of earth-filled tires, stacked on top of each other like bricks and covered in stucco or adobe," but there are several thousand Earthships around the world now, in all types of climates and landscapes, and each home is unique.

Regardless of the type of building materials, common construction design and strategy are used and the homes meet their heating and cooling needs from solar and other renewable energy sources. And true to the concept of a ship, although they have been permanently wedged into the ground, many Earthships remain untethered to a power grid. Most Earthships also incorporate additional sustainable-living systems including in-home greenhouses, low flush toilets and low flow showerheads. Some go so far as to include rainwater catchment systems, grey water recycling (from sinks, baths and washing machines), composting toilets and drought-tolerant, naturalized landscaping.

Earthships use the principle of thermal dynamics to naturally regulate temperature inside the home. Windows on the sunny sides of the building let in light and heat to provide wintertime heating. Solar energy is absorbed by the foundation walls, the "thermal mass," which acts like a battery, absorbing heat during the day to keep rooms from getting too hot, and releasing it into the home at night. Insulation - such as straw bales - prevents the heat stored in the thermal mass from being lost to the outside. At about 2 meters (6 feet) depth, the temperature of the ground varies by only a few degrees and the Earthship design takes advantage of this property to prevent large temperature fluctuations within the house. The homes are built into south-facing slopes or bermed to make use of the temperature regulating capacity of the earth and insulation prevents heat released into the home by the thermal mass to be lost to the earth.

Although the concept has spread to every corner of the globe, the highest concentration of Earthship homes is still in the south-central states of the U.S.A., especially near the Earthship headquarters in Taos, where entire communities have formed of the self-sufficient, off-the-grid homes. A subtle shift is occurring in the construction industry, however, and the Biotecture concept is now being embraced as a possible solution to some of the tremendous environmental challenges faced by this generation.

Mike Reynolds has written a number of books on the Earthship concept and the Earthship/Biotecture homepage (www.earthship.net) offers a comprehensive menu of construction information, codes, laws, forums, books and "how-to" videos. You can also buy a copy of "Garbage Warrior," the award-winning documentary produced by Oliver Hodge, that chronicles Mike Reynolds' fight against "Big Business" and the state legislation that he feels stands in the way of environmentally progressive building standards. Additional information on Earthships is available at www.greenhomebuilding.com where author Kelly Hart discusses principles of sustainable architecture in general and provides an unbiased overview of Earthship construction.