Earthship

An Earthship is a type of passive solar house that is made of both natural and upcycled materials such as earth-packed tires, pioneered by the architect Michael Reynolds.

An Earthship addresses six principles or human needs: 1) Thermal/solar heating and cooling, 2) solar and wind electricity, 3) contained sewage treatment, 4) building with natural and recycled materials, 5) water harvesting, and 6) food production.

Earthships are intended to be "off-the-grid ready" homes, with minimal reliance on public utilities and fossil fuels. They are constructed to use available natural resources, especially energy from the sun and rain water. They are designed with thermal mass construction and natural cross ventilation to regulate indoor temperature. The design is intentionally simple, for example single-storey, so that people with little building knowledge can construct one.

The Earthship concept began to take shape in the 1970s. The architect Michael Reynolds wanted to create a home that would do three things: first, it would utilize sustainable architecture, and material indigenous to the local area or recycled materials wherever possible; second, the homes would rely on natural energy sources and be independent from the "grid"; thirdly, it would be feasible for a person with no specialized construction skills to build. Eventually, Reynolds's vision was transformed into the common U-shaped earth-filled tire homes seen today.

The buildings are often horseshoe-shaped due to the difficulty of creating sharp 90 degree angles with rammed tires. In Reynolds's prototype at Taos, the opening of the horseshoe faces 10-15 degrees east of south to maximize natural light and solar-gain during the winter months, with windows on sun-facing walls admitting light and heat. The book, Earthship I, describes how to find the best angle depending on the building's geospatial location. The thick and dense walls provide thermal mass that naturally regulates the interior temperature during both cold and hot outside temperatures. The outer walls in the majority of Earthships are made of earth-rammed tires, but any dense material with a potential to store heat, such as concrete, adobe, earth bags, or stone, could in principle be used to create a building similar to an Earthship. The tire walls are staggered like traditional brick work, and often have "concrete half blocks" every other course, to equal the length of the staggered tire below. In an effort to cut down the use of concrete even further, they also use "squishies" - tires rammed in between a tight space to even out the course or to compensate for varying tire size.

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Wikipedia