Build for the environment, build for sustainability, build for your future.

Tuesday, May 27, 2008

Earthships: A Green Home Building Alternative

Earthships are sustainable homes designed to interface with their environment. Traditionally, they are built in a circular or U shaped layout and constructed using recycled tires packed with dirt, which weigh about 350 pound each when packed properly.  The idea of Earthship housing was created by Mike Reynolds, founder of Earthship Biotecture,  in the 1970’s as a response to his desire to live off the grid and help the environment.  For this to be possible he felt that his house had to do three things, first he had to provide a sustainable existence while using recycled building materials indigenous to the planet, secondly, he would have to generate his own utilities, and the last thing was to make sure the average person could duplicate his design without having prior construction knowledge…

Why build the walls from used tires?  The method of turning recycled tires into dirt laden bricks is simple, though labor intensive, and since 290 million tires are scrapped each year in the U.S. it is an almost certainty that finding them will be easy and affordable.  How are Earthships created?  Though the traditional layout is circular or U shaped it is not the only design, more and more are being constructed to fit conventional floor designs; since most Earthships are built by the individuals planning to live in them, floor plans and outward appearance varies.  After the shape of the walls have been figured, tires are laid side by side to fit the desired pattern and then filled and packed tightly with dirt; dirt is supplied by digging a 3 foot deep area within the boundaries of the walls, this is one of the ways heating and cooling is achieved within the domicile.  Each row of tires after the first should be staggered, compacted with dirt, and leveled until the desired height of the walls have been reached; voids in the walls can be filled with recycled soda cans and bottles.  The next step is to smooth the inner and outer walls by spreading mud adobe, cement or stucco.  The roof may be fashioned using traditional trusses (preferably from recycled wood,) or by welding re-bar together, then covered with chicken wire and cement; a skylight is usually incorporated in the rear of the structure to help regulate the internal temperature.  The front wall should be sloped and fashioned from recycled glass, and facing south (if building in the northern hemisphere of the U.S.,) so it takes full advantage of available sunlight and heat.  Inner walls of the dwelling can be fashioned by stacking recycled soda cans using cement to hold them in place, and like the outer and inner walls, smoothed out with adobe mud. But having a modern Earthship built isn’t always cheap, construction cost can reach $175.00 a square foot, about $50.00 more than conventional housing, but building one yourself lowers this cost and as with any home, the bigger you build the more money it takes.


Part I


Part II


Part III

The collection of water is achieved by having a sloped roof that has run off points leading to cisterns that lead the water to a water organization module that removes bacteria; the water supply is then pushed into a pressure tank creating water pressure for household use, except for the flushing of toilets.  Water generated from dish washing, laundry and bathing, known as greywater, is collected and run through a botanical cell filtration system which is then used for the flushing of toilets.  Water containing fecal matter and urine, known as blackwater, is collected in a solar-enhanced septic tank and then channeled to an exterior landscaping planter cell.

Electricity is achieved by having on site photo voltaic panels and or harvesting the wind using wind turbines, and then inverting the stored energy from DC to AC using a Power Organizing Module; this system is meant to run house hold appliances but not a heating and cooling unit.  A power generation system cost about $20,000, but since this machine alleviates the need to be hooked up to a local power grid, it will eventually pay for itself.

The climate is controlled by the tires ability to soak up heat during the day and then radiate heat during the night, plus most Earthships are dug into the ground so they are able to take advantage of the earths stable temperature of about 55 degrees.  The positioning of the Earthships southern wall takes advantage of the suns warming ability in the winter by absorbing it, and the angle helps to repel the suns heat in the summer; windows are also placed through out the house to maximize climate control.  Over heating and cooling is a problem when the designer fails to adjust for conditions of locations outside the northern hemisphere of the U.S.; insulation may also be added to help stabilize temperatures.

There are currently around 3,000 Earthships world wide, with about 2,000 in the U.S., though the majority are located in the south west, just about every state has one.  The area surrounding Taos, New Mexico has three Earthship communities; the Rural Eathship Alternative Community Habitat, sits on 55 acres and was opened in 1989; the Social Transformation Alternative Republic, sits on 650 acres and was opened in 1992; the Greater World Community, sits on 633 acres with about 60 houses and opened in 1994.

Sources:
Wikipedia.org
Earthship.net

Other Videos:
View 10 additional videos on earthship.net

Posted by chris on 05/27 at 09:35 AM
BuildingElectricalHeating/Cooling/HVAC/Mechanical SystemsCommunitiesEveryday LifeVideos

Comments:

Register as a new member to leave a comment.