Building in earth is one of the world’s oldest technologies, and traces of buildings constructed in earth 4000 years ago still survive in the arid regions of the Middle East and China. Its versatility (earth can be formed into building materials in at least half a dozen different ways), its durability, and its economy have ensured its survival as a vernacular building system in many parts of the world. The same qualities led to its revival in the 20th century in those parts of the world where the availability of suitable soils, the prevalence of arid-zone climatic conditions, the high cost of industrialized building materials or components, or the survival of a culture of building in earth have favored the introduction of earth-based building materials and systems. Of the several different ways of building in earth, monolithic earth construction, where hand-formed balls of wet clay, with or without natural additives, are built up in courses and left to dry and set, is probably the olde...