Earthbags and Grid Beams.
I am going to consider a root cellar and firepit area made from earthbags.
http://www.earthbagbuilding.com/projects/rootcellar.htm
http://www.earthbagbuilding.com/projects/firepit.htm
Then there is Grid Beam - Erector Sets for Big Kids!
http://www.green-trust.org/wordpress/2011/11/14/grid-beam-erector-sets-for-big-kids/
http://www.gridbeamnation.com/build-it/gridleys-workshop/
http://forums.makezine.com/comments.php?DiscussionID=5260
Modular, a lot of open source, a growing community…this sounds great! I am going to experiment with this for a deck, a garden/orchard cart/wheelbarrow and a dog house/platform. Maybe this will become the frame of a half-buried root cellar?
Maybe just found my first grid beam based project! Solar Hot Water: http://solarcities.blogspot.com/2008/10/solar-c3ities-solar-challenge.html
and someday after more research, a biogas digester:
http://solarcities.blogspot.com/2010/01/how-to-build-solar-cities-hdpe-bio.html
