For the design of building foundations that we will use for CEB construction, we are building on the work documented by Dancing Rabbit Ecovillage. These people are in the same state and climate zone as we are, so their designs are directly relevant.
Rubble Trench Foundation
Dancing rabbit goes through a discussion of the rubble trench foundation, a design which minimizes the use of concrete, goes below the frost line, and uses no insulation:
Frost-Protected Shallow Foundation
The next evolution of simplified foundations is the frost protected shallow foundation. This technique is much more conservative in the use of foundation material - thereby reducing cost and effort requirements - by utilizing insulation on the outside foundation wall. In this example, the depth of the foundation required is halved - down to about 20 inches, from the typical 3 feet required in northern Missouri. The effectiveness of this method relies on the insulation keeping the heat in, and the house transfering the heat from an earthen floor - such that the foundation is kept above freezing.
Factor e Foundation of Freedom
Here Factor e Farm builds on the above and modifies the use of Rastra block to the use of CEB block.