We have been thinking about going to live abroad for quite a while, but the last nudge we needed, was a “Grand Designs” episode on an earthship / ground house in France. I have always been interested in weird and organic architecture and had come across earthships before (I even saw that Grand Designs episode once before), but I never thought it was for me: I have 2 left hands and would definitely not consider building my own house without the proper guidance and education. However as I saw the show again in December 2012, Axel was very enthusiastic – we started talking about it, and realised it would be possible to build an earthship with the help of volunteers or something…
First off, I need to say something about earthships.
There is the name, of course; it sounds as if it could lift off into space any minute. The concept has been around for ages but the name has been invented (and patented, I think) by architect Michael Reynolds, who has an earthship-building company and test ground in New Mexico. Another group calls it a “ground house”, and some people just call it whatever they want to call it.
Basically, earthships are radically sustainable and self-providing buildings, based on 6 principles:
- They are (supposed to be) built with recycled and natural materials: most are built with old tires, but can or bottle walls are also possible, or you could theoretically use stones you find on your land.
- The house harvests its own water, and re-uses it too
- They use thermal and solar heating and cooling only
- They use solar and wind electricity only
- Contained sewage treatment: after water has been used for washing, cooking or drinking, it is filtered by plants and then used to flush the toilets; after that, it goes into plant beds as well
- Food production: a part of the house can be used as a greenhouse to grow vegetables and fruit trees in, especially in extreme climates.
Earthships harvest water on their flat roof, but the back and sides are completely dug into the earth, so it can use thermal wrap as a way to keep constant temperatures, summer and winter. At the (south-facing) front, there is a double glass wall that gets sunlight to come all the way to the back of the house in the winter (nice and warm), but also acts as a heath buffer in summer (when the summer is higher and doesn’t reach to the second layer of glass).
While we were looking for land to build our own earthship on, we also paid a visit to a few existing earthships, did some research, looked at other types of “sustainable” homes, and decided that earthships really sounded too good to be true (at least, in our case). And this is why:
- Most earthships are built with tires. All tires must be exactly the same size, and you spend days and days driving around the country to find companies who have second hand tires in exactly the size you need.
- Although earthships seem to work really well in the desert of New Mexico, in colder countries they need a solid concrete foundation in order to cope with humidity. In our case, buildings built into the mountain have to be extra insulated (by law) in order to keep the humidity out – and this would mean that the thermal heat wouldn’t work as well.
- In Spain, a second layer of glass doesn’t seem to be necessary in the winter; however, it gets far too hot on sunny days.
- In the region where we live, it rains A LOT from time to time, and then it doesn’t rain for months in summer. This means that if you harvest water from your own roof, in september you’ll be drinking the water you harvested in March. It creates a few challenges when it comes to keeping water disease-free for so long when it’s so hot, even when you bury your cisterns under the ground… Also we have plenty of water from a borehole on the land, so we can use the water we harvest as irrigation water only. However, we will build a system that can easily be transformed from a water system depending on a bore hole, to a self-harvesting system. You just never know when your borehole goes dry!
We plan to work with the other principles though. Our house will run on mainly on solar power, even though Spanish law says you need a heating system that can work on gas; we are getting a hybrid system, and hope we don’t have to use the gas too often. We won’t build our house with recycled materials, but we’re making sure most of the materials are produced locally. We will re-use our water and have the sewage filtered by plants; the lower gallery of our house will hopefully be the place where we can keep a few fruit plants that wouldn’t survive the freezing winters outside. We will also be researching and experimenting with several techniques that can make the house work better without external energy: solar powered warm water, a heath pump for air cooling and heating, use of recycled water for irrigation,…
Our first aim is of course to have a home that is cosy and comfortable to live in – but we hope to achieve it by using the best and most sustainable technologies available. This way not only will our housing have a lower impact on the environment, but of course it’s nice to know that things like electricity, hot water or a big part of our food could be obtained for free for the rest of our lives.
Last week, we have finally applied for a building permit (actually, our architect Manel did that), and we’re hoping to start building in September 2014… Let’s see how that works out!