So, continuing from my research on the zero carbon passive house, let us now look at Earth Ships.
“. . . the Earthship is the epitome of sustainable design and construction.
No part of sustainable living has been ignored in this ingenious building.” (earthship.com)
An earthship is a passive house build to be almost completely autonomous, and use as little of public utilities as possible. The water, electricity and sewage systems are build to use as many of the natural resources available as possible.
Electricity is generated by harvesting solar and wind energy, which is then stored into batteries, like those used in a golf buggy. By using a Power Organising Module (POM) the electricity is extracted from the batteries and distributed around the home for use. The POM can also be used in conjunction with the national grid, if needed.
Rainwater is collected from the roof and can be recycled 3-4 times. The first step involves using a pump and filters so the water has enough pressure and cleanliness to be consumed and used within the home. The toilet is separated from the normal consumption channels (washing etc) and only uses the water after it has been recycled three times. Part of the process used before sending the water to the toilet, involves indoor planters which help to purify the water. In many earth ships, these planters are full of food crops for the inhabitant. The fourth recycle is when the water travels to exterior botanical cells which treat the sewage. The cells are also set up so their contents can flow into the conventional septic tank, meaning that the contained tank is additional rather than a replacement.
Hot water is generated in the homes using solar power, or natural gas. A Biomass boiler could probably also be used.
Like other passive houses the heat recovery ventilation system is used as well as super insulation.
With the use of south facing windows and thermal wrap on the back wall, earthships claim to be comfortable in any climate. What is proven, is that a lot less fossil fuels are used with the implementation of these two aspects.
The thermal wrap is part of the insulation which starts with dense mass. Dense mass both collects and stores temperature if backed up with enough insulation. Usually earth is used, but other examples include concrete and stone.
Personally, I think the earth ships are beautiful. Yes, they are a very radical in approach and look more like strange alien growths on the landscape than dwellings, but the effectiveness of their use of recycled materials is unrivaled.
Looking at the Earthship in Brighton, UK (the most relevant in climate to my project) the main construction materials were old tyres, packed with cardboard and earth, which were then stacked and covered with either earth, adobe, or cement. Reclaimed wood and granite were also used in the construction and within the house. For secondary windows (primary windows were triple glazed) old bottles were used, which created a beautiful stained glass effect.
Fundamentally, the materials used in an earth ship need to be locally sourced and recycled or reclaimed, therefore keeping carbon emissions as low as possible.
How can the earth ship influence my building?
My particular site is not open to the south side, making solar power a very difficult resource to utilise. It seems that this is one of the main sources of clean energy of the earth ship. The use of it within my building goes back to my previous question: Could the roof of the first floor living area be manipulated to maximise solar gain?
The site is also in a completely urban setting which isn’t very big, meaning that part submersion of the building in earth would also be unsuitable.
However, in the UK, we get a lot of rain, meaning that the collection of it as a primary water resource would be very feasible. The only problem is, is it possible, according to the size of the site and the location in central london, to implement the water system of the earth ship?
Could it somehow be manipulated to fit within the site?
The thermal system of the earth ship is something that I feel could be integrated into the insulation of my building. The main material being concrete- a dense mass, means that insulation could be implemented effectively. This, of course, depends on the width requirement of the wall in order to do this, and the suitability of fabric formed concrete in this context. This is something I will have to research in my next entry.