Built with natural and recycled materials, Earthships are self-sufficient houses where one can produce their own food, water, and electricity. This kind of architecture started to develop through the end of the 20th century with the efforts of architect Michael Reynolds. Tire and bottle brick walls are probably the most typical examples of upcycling in Earthship houses. Tires are also the most economical and environmental way to achieve thermal mass as there are nearly 2.5 million tires discarded globally every year. Additionally, according to research, shredded automobile tires leach minimal amounts of toxic pollutants compared to other wastes.
By providing thermal mass, the tire walls of Earthships eliminate the need for electricity or burning wood for a comfortable temperature.
However, tires can degrade due to high temperatures, exposure to light, or contact with strong oxidizing chemicals. Therefore, the tires used in Earthships are properly surrounded by packed earth, vapor barrier, stucco, and paint. This process also prevents the odour resulting from the photodegradation of rubber. That is, photons in the light break down rubber polymer molecules which causes the molecules to vaporize. So, the prevention of light exposure also solves the odour problem.
Earthships can also adjust their temperature without any electricity or burning wood. Instead, the structure uses its thermal mass and solar gain. The tire walls surround the building on three sides, creating a thermal mass. During day time, the sun enters from the windows on the south side and heats the floor and the mass. In the evening, the temperature of the air drops below the stored wall temperature, causing heat to be naturally released into the living space. In the summer, the building stays cool with the preserved temperature of the earth. The buried cooling tubes and operable vent boxes further help the cooling system during the summer.
Moreover, each Earthship has its own “power plant” with solar panels that are efficient when combined with energy-saving appliances. An additional small windmill is optional. There are also cisterns to collect water from the rain and snowmelt from the roof. The pump and filter system cleans the water and distributes it to the solar water heater and a pressure tank. Therefore, the structure can meet its own water need for bathing, washing dishes, and laundry. Nothing goes to waste in an Earthship, so the used water flows into the botanical cells or the toilet tanks for flushing.
