Back in the old days, our fathers and grandfathers used to build their
houses using Mud mixed with Straw either with molds to make them look
like Bricks or just manually.
This method - no matter how premitive it was, proved to be energy
effecient and envornmentally friendly.
I was quite surprised to this techniques is back and many houses are
buildt this way. Here is a full article on Straw Bale Building
MEEF - Middle East Economic Engineering