Why use a rubble trench foundation? Because the production of cement accounts for around 7% of all greenhouse gasses. Because of this, it is important to reduce the amount of concrete while building a green home. The need to reduce the amount of concrete is made even more important because of the wide straw bale walls which require a wide foundations.

A rubble trench foundation reduced the amount of foundation concrete by over 50%. As shown in our how-to DVD, the foundation trench is dug below the frost line (about 18" deep in this area) and filled with 1 1/2" stone to just below grade level (see picture). The remaining 8" void is then filled with concrete. Pollution is reduced, money is saved, and the foundation is extremely strong.