It's been a long time but honest to goodness mud is once again being recognised as a highly efficient and sustainable building material. For Rob Hopkins it's less about mud huts and more about exploring an eco-friendly way of living.

Originally from Bristol, England, Hopkins has lived in West Cork for the last four years and is now building a mud-brick home of his own. "Earth is seen as a poor man's building material and I don't think it's been used much here for the last 100 years, whereas in Europe, earth has been rediscovered as a cutting edge material," he says. "The beauty of earth is when you dig out your foundations you then have free building materials."

Earth construction is an ancient technique practised all over the world, which these days involves knowledge of soil science, engineering and building construction. There are four basic techniques: mud bricks, rammed earth, cob building and wattle and daub structures. Hopkins has decided on the cob method for his new home. Starting with a stone plinth foundation of about two feet, the idea is to build in much the same way as you would a play dough house. "The material is very soft and warm," he says, "and you can create all kinds of niches and alcoves to literally hand sculpt your own home." The mixture itself is very sticky and you make what he calls "loaves" which are moulded one on top of the other.

In order to protect the walls from the elements, the outer walls are rendered with lime; the roof should ideally have an overhang of about two feet. In the right conditions, a cob brick structure could be built over a four-month period.

The French have already built an entire mud town called Domaine de Terre and in South Yemen, the town of Sana'a has mud buildings up to 11 storeys high which are deemed safe. At the Centre for Alternative Technologies in Wales, the UK's first rammed earth structure has recently been completed and is open to the public.

The reason earth buildings are so popular is that they are believed to be cheaper to build and naturally insulated. Their design and thick walls make interior temperatures quite stable: in summer, the walls of the house are cooled at night, and in winter, the walls are heated by the sun during the day, releasing heat during the night. As sustainable development becomes more and more popular, countries like Denmark, Holland and the USA are leading the field in mud-building. At the moment there are over 400 mud buildings a year going up across America.

Hopkins is currently planning workshops on building with mud to follow up a successful five-day workshop he held at his farm in Enniskean before Christmas. Lecturers and architects came from the UK to discuss earth-building, and participants were invited to have hands-on experience in the four main fields of construction so popular abroad.

Participants built a six ft by six ft structure using a different technique for each wall.

Contact Rob Hopkins at The Hollies, Enniskean, West Cork, 023 47001