Earthships: The Future of Green Living
Justin Coffey, OTG Contributor
Earthships were first conceived in the 1970’s by architect Michael Reynolds, who wished to create sustainable off-grid living spaces that almost anyone, regardless of prior knowledge or experience, could construct. They’re intended to be “off-the-grid ready” homes, eliminating the need for public utilities or fossil fuels, harnessing instead the power of sun, wind, and rain, and using recycled and indigenous natural building materials.
A typical Earthship is horseshoe-shaped, as its outer walls consist largely of insulated earth-filled tires covered in a thick layer of adobe. These thick, dense walls serve as a thermal mass which, along with earth sheltering and cross-ventilation, regulate the home’s climate without the need of heating or air conditioning systems. The interior walls are usually comprised of recycled cans with concrete mortar, again coated in adobe. The overall appearance of an Earthship resembles a typical adobe building when complete.
Earthships are designed to catch any water one would need from the natural environment, whether in the form of rain, snow, or condensation. Moisture from the roof is channeled through a strainer and is collected in a cistern, where the water is made drinkable; it is then fed into a regular pressure tank to await use by the occupant. The water collected and treated by an Earthship can be used up to four times. Greywater—water that has been used at least once—is used for flushing toilets and watering crops or landscaping. Black water—water that has been used in a toilet—can also be used for use in planters, although it’s not connected to the greenhouse, and watering food plants with black water is not recommended.
Earthships create and store their own electricity, via solar panels and wind turbines, which is then stored in deep-cycle batteries housed on the roof of the home. If necessary, the occupant may obtain additional energy either through generators or by connecting to the local grid. Earthships use a Power Organizing Module, a prefabricated Earthship Biotecture system which converts some of the stored energy for AC consumption, supplying the Earthship with outlet power which can be used to run any household appliance.
There are six guiding principles behind the design and construction of an Earthship.
- Thermal/Solar Heating and Cooling
Because both the earth and sun create and regulate heat without the use of pipes or wires, Earthships can maintain a comfortable temperature, regardless of location.
- Solar and Wind Energy
Earthships use a prepackaged system to produce their own energy, which is stored in batteries until needed.
- Contained Sewage Treatment
Earthships collect, purify, and reuse all household water, serving food production, landscaping, and sewage needs.
- Building with Natural & Recycled Materials
The Earthship website calls it “House as Assemblage of By-Products.” In addition to recycled materials, local natural materials must also be utilized.
- Water Harvesting
Water obtained by the Earthship is used four times, and is heated by the sun. Earthships can rely on city water as a back-up. They do not pollute underground aquifers.
- Food Production
Hundreds of gallons of water from sinks and showers are held in planters known as Earthship wetlands, which are an ideal place to grow produce.
For more information on these “Radically Sustainable Green Buildings,” visit http://earthship.com.
Justin Coffey is a teacher, artist and writer living in Texas.