The name ‘Earthship’ may sound like something out of a sci-fi book, but it refers to a style of home construction designed to be self-sufficient and off-grid. Earthships are designed to use solar power and other sustainable technology, and to minimize waste during construction and throughout their use.
The concept was pioneered by architect Michael Reynolds, who has been developing his green home building designs since the early 1970s. Earthships make use of recycled materials, such as old tires and bottles, to reduce waste and keep garbage out of landfills.
Tires are packed with dirt to form load bearing walls with high thermal mass. Long sun facing exposures with windowed surfaces capture solar heat, which is stored in the walls and released when surrounding temperatures drop. Interior and non-load bearing walls often incorporate plastic and glass bottles arranged in artistic fashion, which allow light to pass and enhance the beauty of the designs.
Earthship designs incorporate systems for managing water, electricity, temperature, sewage, and even food production.
Water and Sewage Treatment
Water management makes maximum use of rain water or snow melt. Water is captured from runoff on the roof or from hills, filtered through silt and stored in a cistern. The water is then pumped and filtered into a pressurized storage tank to provide potable water for drinking, bathing and washing dishes.
Instead of dumping this water straight to waste, it is cleaned and used a second time for growing plants inside the earthship.
That water is also not wasted, but used a third time to operate flush toilets. The water from the toilets is used a fourth and final time to water exterior plants, which are not for consumption.
Electricity is generated through solar panels and wind power. The Earthship team has even designed their own vertical axis windmill, called the Dynasphere.
Earthship Biotecture sells pre-packaged electrical systems that are designed to meet building codes and integrate smoothly into the home’s power system. Their Power Organizing Module (POM) can be installed by any licensed electrician; they don’t need to be familiar with solar and wind power systems.
Earthships are designed to provide comfortable and stable interior temperatures by balancing heat from the sun and the thermal mass of the earth. Heat is admitted by allowing the sun in. Homes can be cooled by admitting the cooler temperatures of the ground.
The designs have been adapted and built in many parts of the world, in different climates.
Plants and Food
Earthships use interior greenhouses for treatment of grey water, as well as to grow food and enhance the natural beauty of the home. The choice of what to plant is highly individualized by the owners and what works in the local climate. Food growing plants aren’t strictly required, but it aligns well with the spirit of independence inherent to earthship design.
The Green Future of Construction
According to a McGraw-Hill Construction market report released in Feb. 2013, about half of worldwide construction firms globally are planning for more than 60 percent of their projects to be green by 2015. There is an increasing demand from the market to build green.
While earthships represent only a small portion of current green homes, if you are thinking about building your own home it is worth doing some research into this style of construction. You can find more information at the Earthship Biotecture website.