Dr. Owen Geiger did an article on the recycled plastic blocks in Mother Earth News.  http://www.motherearthnews.com/hands-on-and-how-to/recycled-plastic-block-houses.aspx  He put the same article up on his Earthbag blog  http://earthbagbuilding.wordpress.com/

If the name Dr. Owen Geiger sounds familiar it’s because it should be.   His passion and expertise is sustainable housing.  http://www.motherearthnews.com/Green-Homes-Expert-Owen-Geiger.aspx  http://www.grisb.org/