Foundation (engineering)
A foundation is the element of a structure which connects it to the ground, and transfers loads from the structure to the ground. Foundations are generally considered either shallow or deep. Foundation engineering is the application of soil mechanics and rock mechanics (Geotechnical engineering) in the design of foundation elements of structures.
Earthbag construction
Construction usually begins by digging a trench to undisturbed mineral subsoil, which is partially filled with stones and/or gravel to create a rubble trench foundation. In high seismic risk regions a reinforced concrete footing or grade beam may be recommended. Earthbag buildings can also be built on conventional concrete slabs (though this is more expensive and uses more embodied energy than a rubble trench foundation) and can have a bermed or underground "floating" foundation like an earthship as well.