While scrolling around the net I came across the most interesting article about houses made of dirt. Take a look and see that I'm not talking about your average mud hut!
This type of construction is know as "cob" and has been around since the 11th century. It has recently seen a surge in popularity and considering costs for lumber and other construction materials, I can see why.
To read more about these interesting homes, please visit: http://www.environmentalgraffiti.com/featured/buildings-dirt-and-straw/3739 and read the article by Kelly Taylor.