By Mick Jensen
A sustainable “earthship” house made from recycled soil-rammed tyres – the first of its kind in the district – is taking shape at the edge of Ashburton.
Embracing the efficient, eco-friendly building method are self-builders Dawn and Lance Kirkland, who are stepping closer to the dream of living off the grid, off the land and into a life of low living expenses.
A building permit has just been granted to erect the 110m2 home on their 1ha lifestyle block.
The home will consist of three pod rooms and 800 recycled tyres will be stacked tightly like bricks and packed with soil to form monolithic walls.
With high insulation and flame retardant values, the walls will be 800cm wide and will be plastered with a pigment based mix that will keep future maintenance to a bare minimum.
The walls will be warmed by the sun and will release heat when it cools down.
The home’s angled glass front will reflect the sun’s heat away in summer, but will allow it to reach the back of the house in winter.
“Inside the whole building will breath at a fairly constant 18 deg. C,” Dawn said.
Cooling tubes would act as vents and would be angled into the house to bring in air.
There would also be light vents.
A one-off investment in 12 solar panels would have a pay back period of around 10 years, she said.
The panels sit next to an eco power room, built of bottles, cement and plaster, that houses the inverter.
Similar building methods had been employed by the couple to erect a chook house, two “keyhole gardens” and a soon-to-be completed holding tank that can store 6000 litres of water and is supplementary to two 10,000 litre tanks already on the property.
Water from the new home will be used and reused and filtered through exterior planters called botanical cells.
estimate that once the home is completed, they will be able to catch rain from a combined building area totalling 260m2, including 17m2 from the solar panels.
Lance Kirkland said the earthship house would be 14 tyres high, 2.2m high from the ground level and over 3m at the front.
“We’ll have a six-degree angle pitch on the roof, which will be made of iron and oregon beams.”
Mr Kirkland said the build project was expected to take six months and to cost around $150,000.
The couple are living in a caravan and sleeping in a cabin on site while they undertake the project.
A retired builder will offer guidance and lend a hand with construction and other trades people will be brought in as needed.
Mrs Kirkland said a similar sized conventional home would cost around $300,000 to build and would not have the same running costs or sustainability features that they wanted to embrace.
She said the couple had “sailed through” the building permit process because they had done their homework and had supplied all of the relevant information to Ashburton council.
It had more than met requirements around ventilation, light and insulation.
The home was a first in the district and one of only a handful that they knew about in the country.
“It’s just so exciting – we’re going to be off grid, off town water and sewerage and producing our own food – it’s a dream that’s now becoming a reality.”