What is an earthship?

An earthship is a variety of off-grid passive solar home—or community of homes— made of natural and recycled materials such as old tires and recycled cans. Based upon 6 core principles, Earthships were designed by architect/designer Mike Reynolds in New Mexico in the late 1970s. These homes are typified because they make use of non-polluting renewable energy sources and smart design to meet most if not all heating, cooling and power needs.

The Earthship is defined by:

• building with natural and recycled materials
• thermal/solar heating and cooling
• water harvesting
• contained sewage treatment
• solar and wind electricity
• food production

For Earthships, reuse is central. Old car tyres are used as the ‘bricks’ for wall construction with an optional ‘berm’ of about 100 tonnes of dirt piled against the walls to roof height, giving the advantages of an earth-sheltered home.

Rendered internally with adobe and externally with a cement-based render, the wall finish looks similar to that of a strawbale wall. A greenhouse frontage is also a common feature. Double-glazed, angled glass on the north (sun-facing) side of the house provides the thermal engine of the home, along with a great place to grow food.

This can be combined with the berm for heating and cooling. Heat energy captured by the greenhouse gets stored in the thermal mass of the berm and then, when indoor temperatures drop, released back into the living space. The greenhouse not only traps heat but can also be used to drive a thermosiphon: hot air is exhausted out large vents in the greenhouse roof causing cool air to be drawn into the living space through ‘earth tubes’ buried in the berm.

Earthship designs also include greywater reuse for plants in the greenhouse, blackwater treatment onsite, renewable energy systems, and water capture and storage. Every drop of water that lands on an Earthship roof is used four times, so homes can subsist and even thrive without taking water from the ground or municipal sources.

Australia now has over half a dozen Earthships and you can check out the history of the Earthship movement in Australia here.

Some other resources:

Comfort in Any Climate
The concept of thermal mass buildings works both to cool and to heat a home. Earthships keep you comfortable in any climate, anywhere in the world.

Earthship Biotecture design principle: ‘Thermal/Solar Heating & Cooling’ details how Earthships maintain comfortable temperatures in any climate.

Earthship Book: ‘Water from the Sky’
Takes its readers from problem to solution. It addresses the water shortage in New Mexico, the United States, and around the world. Step by step, the book outlines how to solve the problem of water shortage through catching, storing, using, reusing and treating water.

You can also apply the 6 principles of Earthship Biotecture to an existing building. Another option is to send your local builders to an Earthship workshops in the USA or around the world.

Links:

Earthship principle – water re-use https://www.youtube.com/watch?v=2QGhhDbigXg

Contained water in Earthships https://www.youtube.com/watch?v=bb35zQcGseA

Earthships in Australia https://www.facebook.com/watch/?ref=saved&v=5347834218646153