Earthships

HOMES OF THE FUTURE...TODAY

the homes are primarily constructed to work as autonomous buildings and are generally made of earth-filled tires, using thermal mass construction to naturally regulate indoor temperature. They also usually have their own special natural ventilation system. Earthships are generally off-the-grid homes, minimizing 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 sun-facing walls admit lighting and heating, and the buildings are often horseshoe-shaped to maximize natural light and solar-gain during winter months. The thick, dense inner walls provide thermal mass that naturally regulates the interior temperature during both cold and hot outside temperatures.

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http://en.wikipedia.org/wiki/Earthship