Thursday, December 15, 2011

Earthships and Tire Homes

Americans discard an estimated 253 million automobile tires every year. Nearly half of them end up in stock-piles or in landfills. - Scarp Tire Management Council.

The Nest takes the Earthship "Self-sufficient with ecological awareness" concept and combines it with the Volkswagen "economically available with limitations" concept. - Michael Reynolds, The Nest Concept.

In the words of Michael Reynolds, originator of the Earthship Idea, the earthship "is a completely independent globally oriented dwelling unit made of materials readily available in most parts of the world."
Let's see what Earth-Ship is. Webster dictionary defines it as "A registered trademark name for houses built with tires, aluminum cans, and earth".
these are passive solar homes made with indigenous readily available materials and waste products.
These are the structures made from automobile tires packed with dirt and stacked on one another like huge bricks, and are made in U-shaped rooms. The curving walls are covered with stucco or earthen plaster, which hides the evidence of tires and gives the look of adobe structures. The Front face usually consists of sloping glass that gathers up the sun to heat the house. Sunlight also supplies the indoor planters that provide food and purify waste water.
earthships are equipped with photovoltaics to generate heat and electricity. The Earthship sports a unique roof design that collects the rainwater or melted snow, which can be stored in the flanking two cisterns, big size water-storage tanks that collectively can hold up to 10,000 gallons of water. This is purified in a series of filters, this water supplies all domestic needs.
Earthship consists of two parts :- the U shaped living spaces and the environmentally interface corridor.

Advantages :-
  1. One of the most environmentally sustainable forms of housing available in the industrial nations of the world, especially given the independent living systems that they incorporate.
  2. Use of waste (discarded automobile tires) reducing the demand of natural resources.
  3. Use of indigenous materials available near the building site such as vigas, mud plaster and packing dirt.
  4. Materials required can be found worldwide in abundance.
  5. Reduces stockpiles of tires that can catch fire and smolder for months on end.
  6. relies on Passive solar heating and photovoltaics for electricity, reducing the demand of fossil fuel energy to light and heat the house.
  7. reduces resource demand and pollution
  8. decrease the dependance on utility power, saving money on energy bills
  9. capture rainwater and melted snow, recycle wastewater and grow food
  10. recycling of greywater protects groundwater and surface water supplies from depletion and pollution.
  11. Earthships are resistant to fire, termites, earthquakes, tornadoes and hurricanes.
  12. protect the inhabitants from outside noise.
  13. Easy to build on one's own if the detailing is ready.
  14. Durable form of housing than conventional housing giving the array of other benefits.
  15. Could be used in developing countries to promote self-sufficiency.
  16. Interiors are relatively humid and easy on nasal passage ways.
  17. a proven technology often accepted by building departments.
  18. compete well economically with other forms of earth-friendly housing.
Disadvantages :-
  1. Getting approval for Earthship construction varies by state.
  2. although earthships tend to be warm when the sun is down, it can be cold during cloudy periods, because the mass is situated too far back in the housing to absorb incoming solar radiation directly, so backup heating system is required.
  3. Even though tire walls are easy to build, costly mistakes can occur with no or less experience.
  4. tire walls are labour intensive and labour is costly in most of the parts of world.
  5. Slanted glass designs can overheat, especially in the fall. Curtains or window shades required to avoid this.
  6. as in any solar home, sunlight can be intense during much of the day, creating eye-straining glare on computer screens.
  7. Due to planters and 'u'shaped walls, the effective livable space is lesser compared to conventional homes
  8. lack of storages and closets as lesser niches so care has to be taken to incorporate that in design
  9. Humidity can be problematic due to plants so a vapor barrier between ceiling and insulation is necessary.
  10. the open design that gives good air flow, can be problematic for privacy and noise problems.
  11. If growing vegetables in planters, insects like white flies and aphids can be a big problem.
Source :- The Natural House by Daniel D. Chiras