February 10, 2008

Earthships are earth-sheltered autonomous buildings made of tires rammed with earth, which are usually arranged in “U” or horseshoe shaped modules. Each tire is rammed full of earth manually using a sledge hammer. Windows on the sunny side admit light and heat. The open end of the “U” shaped structure faces South in the northern hemisphere, and North in the southern hemisphere, so that the house will catch maximum sunlight in the colder months. An Earthship is designed to interface with its environment wherever possible and create its own utilities.

Internal, non-load-bearing walls are often made of a “honey comb” of recycled cans separated by concrete. The walls are then usually thickly plastered, using the pull-tabs on the cans as a lath to hold the adobe and stucco. This is known as a tin can wall. The roof of an Earthship is heavily insulated.

The Earthship, as it exists today, began to take shape in the 1970s. Mike Reynolds, founder of Earthship Biotecture, a company that specializes in designing and building Earthships, wanted to create a home that would do three things. First, it would be sustainable. It would use material indigenous to the entire planet as well as reuse materials wherever possible. Second, his homes would generate their own utilities and be independent from the “grid” so they would be less susceptible to natural disasters and free from the electrical and water grids that Reynolds considered ugly. Finally, it would be available. He wanted to create a home that the average person with no specialized construction skills would be able to create.

Eventually, his vision took the form of the common U-shaped earth-rammed tire home seen today. However, as a concept, the Earthship is not limited to earth-rammed tires. Any dense material with a potential for thermal mass, such as concrete, adobe, or stone can be used to create an Earthship. However, the earth-rammed tire version of the Earthship is now the most common for several reasons, and is usually the only structure referred to as “Earthship”.

Unlike other materials, rammed-earth tires are more accessible to the average person. Scrap tires are indigenous to all parts of the world and easy to come by; there are an estimated 2 billion tires throughout the United States. According to the Scrap Tire Management Council, as many as 253 million scrap tires are generated each year in the United States and of those 253 million tires only 53% are reclaimed by the scrap tire market. In addition to the availability of scrap tires, the method by which they are produced, the ramming of the earth, is simple and affordable.

The earth rammed tires of an Earthship are usually assembled by teams of two people working together as part of a larger construction team. One member of the two person team shovels dirt, which usually comes from the building site, placing it into …