BIOCONSTRUCTION: HOMES FOR A CHANGING WORLD
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Homes for a changing world
Our home is our protection from the elements, and requires certain resources for it to operate well, such as fuel, electricity and water. As the world around us changes, and these resources are sure to become more scarce, many are taking up the challenge of finding new ways to live comfortably without needing to consume so much, which also means being a lot more self-sufficient and immune to energy price rises or uncertain markets. A response to this challenge are the “Earthships”, of which a few hundred can be found dotted around the globe.
The central idea to this type of building is to use car tyres as building blocks. Tyres are stacked like bricks, and each one is then rammed full of earth, with eco-cement and cans used to fill in the gaps between them. Eco-cement is made up of 2/3 magnesium oxide instead of Portland lime, which makes it a lot less toxic (by the way, did you know that the chemical processes involved in using standard cement give off CO2? Another good reason to use a more ecological alternative). This wall of tyres is so solid, and the weight is so well distributed, that there is no need to build foundations – that instantly saves using many Tonnes of cement in the concrete!
The Earthships are built into a hill, so the back wall is actually underground. The 2 metre thick walls have layers of damp proofing, insulation and rammed earth that makes up a thermal mass which absorbs heat during the day and lets it out again at night as it is needed, in order to keep the living space at a constant temperature of around 20 ºC.
The front of an Earthship is South-facing, all made up of triple-glazed glass panels, which are slanted at right angles with the apex of the winter Sun, so as to make the most of it in the winter when it is most needed, while shielding the interior from the hot summer rays. This gives it a striking yet appealing look from the outside.
Along the inside of the glass front is an air lock or corridor which acts as a greenhouse (where plants are grown) and as a heat collector. A simple convection ventilation method, with skylights along the top back roof, allows the inhabitants to control the temperature inside the house. From desert areas to the coldest climates, this system keeps the living space at a constant 18 to 22 ºC, day and night, all year round, whatever happens outside, completely eliminating any need for extra heating. Extremely cold areas such as Siberia only need a second air lock to secure the temperature inside (since, as we can all guess, most of the heat from a house escapes when you open the door to the outside).
Clever design allows these Earthships to make the most of all available light and their earth adobe walls to produce beautiful, light-filled interior spaces.
Rainwater collection methods and tanks, good water usage and recycling (as we saw in article number 2 of this series), plus solar panels for all additional energy needs, mean that these pods in the earth are a proven way to live life sustainably while still enjoying modern comforts.
Would you like to know more? Visit www.earthship.co.uk. It may inspire you to be the first to build one on the island of Ibiza… We certainly have the necessary spare materials!