On Thursday 2 July I drove to Stanmer Park just outside Brighton to visit the Brighton Earthship, arranged by the Sustainable Business Network on behalf of the University of Brighton’s Green Growth Platform.
Along with 10 other guests we met our lovely guide Jane Glenzinsko at 9.30 and trekked somewhat breathlessly up a track for 10 minutes to the site of the Earthship.
After a tour of the inside and outside of the construction Jane provided a detailed history and explanation of the project.
Earthships have evolved over the last thirty years from the pioneering work of Michael Reynolds, Earthship Biotecture and the residents of the 3 Earthship communities in Taos, New Mexico.
Earthships are ‘green’ buildings, constructed using waste car tyres and other recycled materials. They use the planets natural systems to provide all utilities – using the sun’s energy and rain to provide heat, power and water. They are buildings that heat and cool themselves, harvest their own water and use plants to treat their sewage.
The basic building block of the earthship walls are used car tyres. The UK throws away over 48 million of these annually and they are now banned from landfill. The preparation method is quite simple. Line the tyre with cardboard, fill it with earth and ram the earth down with a sledge hammer until the tyre is fully inflated.
All tyres are worked on in-situ, being pounded a course at a time and together with a 1m of rammed earth behind them they create thick walls of thermal mass. Finally the tyres are rendered over with mud, adobe or cement.
Another waste material used in the earthship are glass bottles, which are cut up and taped together to form glass bricks. The glass bricks are then laid in courses in cement to form a wall, which are finally rendered over and look like stained glass. The hall floor is made from reclaimed granite and marble off-cuts from a local monumental mason in Brighton.
The sun provides heating by using a dynamic combination of solar gain, thermal mass and super insulation. The walls act as a storage heater. Behind the tyres and earth is the thermal wrap or insulation blanket that separates the mass from the earth that is sheltering the building.
The structure is orientated towards the south, which maximizes the opportunity for solar gain. The front glass windows are angled to allow for maximum sunlight during the winter months when it is most needed, but reflects it during the summer months when the sun is higher in the sky. The heat from the sun is stored in the thick walls and is slowly released during the night and colder days and seasons – the same as the heat you can feel emanating from a stone wall in summer after a sunny day. The size of the thermal store enables heat to be stored inter-seasonally over a long time.
The earthship also generates 20kw from 4 renewable technologies – photo-voltaic panels and a wind turbine for electricity; and solar thermal panels and a wood pellet stove for water heating. The earthship is zero carbon and there are no utility bills.
Earthship Brighton harvests all the water it needs from the sky. All rain water is collected, used and treated on site, saving on infrastructure investment and not depleting the overstretched ground water in the drought stricken south-east of England. The area of the roof coupled with the average annual rainfall for Stanmer Park means that it can harvest around fifty thousand litres (50m3) of water per year.
The rainwater flows from the roof through two filters, including a vortex filter, into four underground water tanks. There is enough room to store twenty thousand litres of water, which is enough to supply the earthship for two to three months.
This was a thought provoking and entertaining tour and presentation – a visit is thoroughly recommended.