I like the post and beam idea. it is one of the oldest structural formats for built structures. I would hope that we could move away from either wood or metal as primary structural members, however.
There are structural components availble made from recycled plastic that have been used to buil bridges and railroads.
Such composite materials were used to build a bridge at Ft. Bragg NC that supported loads (Abrams tank) of 70 tons.
http://finance.yahoo.com/news/Axion-International-Announces-bw-3739724932.html?x=0
http://igsfederal.com/thermoplastic-composite-tank-bridge-dedication.html
I have an e-mail in Axion requesting info on products that might apply to post and beam residential construction.
Buildings with Underground components ordinarily require waterproofing systems. Such systems are readily available but they are not always 'green friendly'.
I'll see what I can find.
James Ball wrote:All homes in the desert should be a least partially underground. It is the coolest place to be!
With regard to Axion recycled Structural Composite Plastics, I had e-mail back from marketing guy who says that, while their products are readily usable in exterior residential applicattions - shade structures, bridges, deckings-, they do not currently have structural products available that would meet the shear/expansion/contraction co-efficients involved in residential structral wall installations. there could also be connection/attachment issues with other structural components or substrates.
there is another residential structural application similar to post and beam that uses 16" wide I-joists that has been used in passivehaus construction. i will see what i can find out about that structural application.