A group of builders in Wales are setting out to prove that some of the best technologies are waiting to be re-discovered rather than be invented in a laboratory by scientists.

Charles Rhodes visits the straw building site in Wales

Amongst the foothills of Snowdonia they are using a building technique that dates back to the Stone Age.

The timber-framed straw theatre will be completed in July, and packed with exhibits showing visitors how to adopt a sustainable lifestyle.

Bale frenzy

They call it bale frenzy when a group of straw balers start building. The bales are made from the dead stalks and unwanted waste left by grain crops. Twine and hazel hoops hold them in place.

They call it bale frenzy

Development director Paul Allen explains that the building was started as a response to people's questions.

"People would ring us up and say, we've heard about straw bale technology - does it work in Wales?

"So rather than do an academic study, and look at lots of straw in lots of detail, what we actually do is build a building. Then we can monitor the costs, how long the building lasts, the moisture levels - and we will be able to tell people based on practical, real advice whether it works here."

Straw: waste product or prime building material?

The supporters of straw as a building material say the walls won't burn, or become home to unwanted pests, because they are covered in render once they are constructed.

"The bales don't burn because there's no oxygen," says Mr Allen.

"The straw is so densely packed that you can spray it with a blow torch and it won't catch fire. And on top of that, it is covered in a lime render two inches thick."

They also say the buildings offer twice the insulation value required by British building regulations - not a bad use for something farmers used to burn.

Fashionable building material

In the United States, straw has become a fashionable building material, and builders have been using it for years.

The finished product: animal shelters in the UK have been made of straw for years

It all started in Nebraska, where settlers had few trees to chop down. They turned to straw to build their homes - reviving an ancient skill that is now used to build offices, homes and factories.

Farmers in Britain have long used straw bales to construct temporary animal shelters.