Earthships

This article originally appeared in the Kildare Nationalist newspaper. 

All of us live in homes that are dependent on larger systems to operate: electrical grids, heating and plumbing. Most of our homes require large amounts of energy to run, which we burn fossil fuels to acquire. We also have all kinds of waste products – tires, soda cans – that fill up landfills, never to be used again.

A few decades ago, however, one American began to think through, meticulously, how many of these problems could solve each other. Michael Reynolds called his solution the Earthship, a home built to be as efficient and self-sufficient as possible, using mostly free materials that are either natural or recycled. The Earthship is designed to require as little energy as possible to maintain, to recycle its air and water as much as possible, and to provide food for people inside the house.

In order to keep the temperature as constant as possible, Reynolds planned for his Earthship homes to be surrounded by earth on three sides, usually built into hillsides. As the weight of the surrounding hill would make straight cement walls unstable, Reynolds created walls made of earth-filled tires, curved to allow the hill’s pressure to dissipate around the structure.

Tires turned out to be an inspired choice for building material – there are more than two billion old tires in the world, and they do not biodegrade naturally, so they clutter up landfills. They do hold earth well, however, and a wall of connected tires covered with a plaster can be very sturdy, earthquake-resistant and fire-resistant.

Reynolds also designed the top of the structure to catch rainwater to use for the household, and the buried sides to insulate the house. Other spaces around the front can be made with cement – but Reynolds likes to use old soda cans as filler, to make the structures lighter and to save money buying cement. Another popular technique for Earthships is to use old glass bottles as filler, thus saving mass and cement while also creating insulation – from the air inside the bottle – and creating a small coloured window, all at once.

On the south face of the Earthship – or the north face, if it’s being built in the Southern Hemisphere -- Reynolds placed large windows under an overhanging roof, letting the low sun into the house in the winter when it’s most needed, and keeping the high sun out during the summer when it’s needed least. All day, the sun warms the interior walls and floor of the Earthship, which release the heat slowly over the cold night.

Since the front windows act like a greenhouse, most Earthship owners create a garden bed just inside, a mini-greenhouse in which they can plant crops. The plants, in turn, can be supplied with a steady supply of water from the house with wastewater from the shower, bath, or sink. The system acts like a permaculture garden, which I wrote about in this column a few weeks ago – everything is recycled over and over, and nothing is wasted.

The effect of all this is a home that anyone can build themselves, using readily available materials, and that will stand up to time and the elements. Such homes can be fitted for electricity, heat and water pipes, of course, but since they are designed to get maximum light and heat from the sun and typically have rainwater collection, and recycle everything in the house, there is little need for bringing in energy or resources from the outside. If people around the world built using these principles, much of our annual expense on mortgages, heating and food would disappear, as would much of our society’s carbon emissions that are changing the climate.

The Earthship concept grew by word-of-mouth, and now there are Earthships – using very little energy and largely off-the-grid – in almost every state of the U.S. The technique is now expanding into Europe, although might need to be adapted somewhat to a climate like Ireland’s, though would probably need to be built level to the ground rather than under it in this damp country. 

If you are considering building a home yourself, look into the Earthship design – check out Michael Reynolds’ books, Earthship I, II and III, or Google “Earthship,” and consider learning more about this ingenious method. You can also look at a short video about Reynolds at http://www.whatiswaste.com/earthships.