Earth is one of the simplest construction materials, and all earth buildings have the same basic constituent parts: soil from the ground, and water. These are mixed together and formed into shapes, and then the water evaporates to leave an earthen structure. Other materials can be added to the mixture, either to help with production, or to improve the mechanical properties of the finished product. Soil types, construction techniques and building traditions vary greatly across the world, and many techniques are variations and combinations of those described.
There are many ways to form earth into structures, this website deals with techniques where earth is the major constituent material. The techniques are split into two classes: those in which independent units are constructed, dried, then transported and laid to form a structure – namely adobe and compressed earth blocks; and those where homogeneous monolithic constructions are produced in situ, such as cob and rammed earth.