4. Earthships
Michael Reynolds got the idea for earthships after watching a television special about the possibility of a looming garbage problem. Soda cans were made out of steel, so they weren't recycled, and Reynolds saw their potential as a building material. During the energy crunch of the 1970s, he discovered that packing dirt into recycled tires created good thermal mass. The earthship was born from these revelations [source: Cooper].
To build an earthship, you fill old car tires with earth and stack them like bricks. Because the tires are so thick, you don't need a foundation, and the tires are plastered after stacking. Internal walls are made from aluminum cans or bottles. These materials would otherwise be thrown away, but when assembled properly, they can save a good deal on heating and cooling costs. Earthships commonly are built right into the ground, with the exposed wall made out of tires pointed out to the sun.
To read about more earthen dwellings and how you can live underground, keep reading.
