Motivated by his will to help protect the Earth's environment, Dennis Weaver, a former actor who appeared in T.V. shows like "Gunsmoke", hosts the above video about the construction process involved in constructing these homes, called "earthships". Michael Reynolds is the innovator of this design and he's spent many years experimenting with his technique, and has even written several books on the topic. Earthships utilize soil, old tires, and cans (amongst other salvaged materials) to create a cheap, easy to construct, and eco-friendly living space.
The main idea behind an earthship is that all of the main structural walls are constructed by collecting thousands of old tires, which are taken from local junkyards and landfills, and densely packing them with earth. Each tire can supposedly hold between 200-300 pounds of earth, at which point them can be stacked one-on-another like massive bricks.
The choice to use tires filled with earth to construct the walls of a building has many advantages: everything from being highly stable, well-insulating, easy to construct, and of course cheap - but along with all this is also the fact that landfills across the country are stacked high with old tires which generally have no purpose once they can't be driven on anymore, so this is the perfect way to reuse a product that would otherwise just be accumulating into massive heaps of garbage. Also, its pretty common for large piles of tires to catch fire, which ends up releasing large amounts of hazardous chemicals and other waste into the environment.
After much fine tuning of the design, construction began on an enormous earthship located on a hillside in Colorado to show that this crazy approach to sustainable housing was not only a realistic, but also practical. In 1989 the "Sunridge Earthship" project was completed, becoming Colorado's first, and the world's largest building of its kind (at least up to that point). After its completion, the home contained over 3,000 tires, each with around 300 pounds of dirt, which make up the supporting foundation for the entire building. The roof is supported by wooden rafters, and the nonstructural interior walls, like closets, stairs, and bathrooms, are made from a combination of mortar and stacked aluminum cans (shown in the picture below)
As a result of the large mass of the home's walls, the building requires no traditional heating or cooling system because the walls store heat and insulate the interior during cold months, and prevent the temperature from rising above comfortable levels during the summers. The home is also oriented southward with large front facing windows which utilize the greenhouse effect to regulate temperature during the winter and allow for the year round growth of fruits and vegetables within the home.
Another achievement of this project is that it's completely off the local electrical grid, and relies fully on solar and wind generators for its electrical power. Much of the water used on the property comes from rain and well-water, and the "gray" water from bathing and other uses is recycled.
Check out (http://www.earthship.net/) for more information on Michael Reynold's earthships.