Friday, April 13, 2007

EarthShips: Building The Future

One very important aspect of the Earthship Concept is to be available to the masses. That is to say, it cannot be a multi-million dollar vessel that only the rich can afford. Everyone is entitled to voyage into the future. The concept, design, and actual method of manifestation of an Earthship must be developed with this in mind. In addition to interfacing with natural phenomena, this concept must interface with the nature of the common person.

What is an Earthship?
The Earthship is an independent globally oriented dwelling unit made from materials that are indigenous to the entire planet. The major structural building component of the Earthship is recycled automobile tires filled with compacted earth to form a rammed earth brick encased in steel belted rubber. This brick and the resulting bearing walls it forms is virtually indestructible.

The Earthship design is based on the principle of Thermal Mass. The tyres are packed with earth, and then stacked atop each other. The gaps are filled with cement and the structure is skimmed with plaster. The tyres give the structure a solidity and water-resistance an Adobe hut would lack. Thick walls ensure the internal temperature is very stable, says Reynolds. The knock-on effect is that little energy is needed to heat or cool the building, meaning electric power from solar or wind sources is devoted to lighting and powering appliances — of which the most energy-greedy is the fridge.

Integral to the design is that Earthships are south-facing in all but the hottest climates. That gives maximum exposure to the sun, both for warming the house and for solar power. Roofs are designed to catch water rather than run it off. Water is then passed through multiple filtration systems to be used for drinking and washing, then household uses and finally gardening.

Reynolds estimates that if you pay builders, an Earthship cost roughly the same as a conventional house - an average $200,000 in the US. The Low Carbon Trust (which aims to be the first stop for European Earthship enquiries) is hoping to drop the cost to around £80,000 for a three-bedroom house, about £65 per square foot — cheaper than conventional housing. The typical delivery time they expect to be six months said Howarth.

Each tyre takes about 10 minutes of hard, bone-shaking work to fill with rammed earth using a light sledgehammer. To prevent the earth spilling, the bottom of the tyre is lined with cardboard, another plentiful and free building material. This design is built around a double U-shape which maximises the frontage exposed to direct sunlight and the space available for solar panels.

The team from Taos pound the earth with practised grunts while the paying guests mill around and take occasional stabs at work. But by the end of the second day a rhythm has settled and the outline shape of the whole building had emerged.

The final seminar was spent on water management, perhaps the most intricate part of the process, and the least understood. Solar energy solutions are now widespread. Rainwater management is under-used and brings its proponents into direct contact with health and safety standards.

Water collection starts with the roof, and Reynolds recommends an enamelled metal roof as the most economical, durable and drinkable solution. Rainwater is collected into a tank, and from there passes through several filters to ready it for drinking and bathing. First-use water runs off from the shower or sink and is then recycled to the toilet. From there the water proceeds through another filter and into the garden. Reynolds showed us photos of his Taos set-up with banana trees fed entirely from third-use water.

“Its not a widescale thing yet” says Reynolds as he looks over the building site.” but it is much broader than when it started. ..we had to learn to make a building out of tyres, cans and bottles. That took a decade or so. Look how long traditional building has been around, . It’s a good thing it didn’t go faster, but we are ready now.

“In the future, if we can sell people a product that will take care of them without expense and without the insecurity of relying on municipal power water and sewage — if you can sell that, everybody’s going to be interested.”

As land gets scarcer in the UK; as technologies improve, allowing us to work and communicate without mains electricity or phone-lines, demand for Earthship-style solutions will increase exponentially. Whether planners will allow us to set sail for these futuristic dwellings is another matter.

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