There are modern alternatives to concrete and wood which are cheaper. A house built of expanded polystyrene - basically a denser version of styrofoam with a ha

There are modern alternatives to concrete and wood which are cheaper. A house built of expanded polystyrene - basically a denser version of styrofoam with a hard shell over it - can be had for a materials cost of about $30K http://manolohome.com/2008/08/11/the-habitat-for-the-21st-century/ http://manolohome.com/2008/08/11/the-habitat-for-the-21st-ce... I could easily see something like this becoming ultra-cheap with economies of scale. Make them in a factory and ship them in a few truckloads, then snap them together almost like legos. This is not the only alternative to wood and concrete. If you look around, a lot of people are working on modern (or not so modern) alternatives.