Advert: date=October 2008

An Earthship is a type of passive solar home made of natural and recycled materials. Designed and marketed by Earthship Biotecture of Taos, NM, the homes are primarily constructed to work autonomously and are generally made of earth-filled tires, utilising thermal mass construction to naturally regulate indoor temperature. They also usually have their own special natural ventilation system. Earthships are a type of off-grid home, which minimizes their reliance on public utilities and fossil fuels.

Earthships are built to utilize the available local resources, especially energy from the sun. For example, windows on the sunny side admit light and heat, and the buildings are often horseshoe-shaped to maximize southern (or northern in the southern hemisphere) sunlight and warmth in the colder months. Likewise, the thick, dense outer walls provide effective insulation against summer heat.

Internal, non-load-bearing walls are often made of a "honey comb" of recycled cans joined by concrete and are referred to as tin can walls. These walls are usually thickly plastered with adobe or stucco.

The roof of an Earthship is heavily insulated - often with earth or adobe - for added energy efficiency.

History

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, using material indigenous to the entire planet as well as recycled materials wherever possible. Second, the homes would rely on natural energy sources and be independent from the “grid”, therefore being less susceptible to natural disasters and free from the electrical and water lines that Reynolds considered unsightly and wasteful. Finally, it would be economically feasible for the average person with no specialized construction skills to be able to create.

Eventually, Reynolds' vision took the form of the common U-shaped earth-filled tire homes seen today. As a concept, the Earthship was not limited to tires - any dense material with a potential for thermal mass, such as concrete, adobe, or stone could theoretically be used to create an Earthship. However, the earth-rammed tire version of the Earthship is now the most common design, 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 ubiquitous around 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 marketFact: date=August 2007. In addition to the availability of scrap tires, the method by which they are converted into usable "bricks", the ramming of the earth, is simple and affordable.