I've recently been living in Cloughjordan - home to Ireland's first ecovillage - http://www.thevillage.ie/ - and a diverse and interesting bunch of people. As well as constructing traditional looking houses and buildings in lime hemp, cob and other green materials, they're also interested in more unusual constructions - such as the hexayurt.
The hexayurt is a low cost emergency shelter designed to be built quickly and easily from locally available materials. The original design by Vinay Gupta is public domain and variations of the original design, like this H13 (using 13 sheets of ply or similar 8x4 sheets) continue to come from designers all over the world.
