From raw soil to finished construction

Depending on the composition of the soil and the required properties of various building elements, a wide range of earthen construction methods has developed over time. In some cases, soil materials are used almost directly. Loam, for example, can be applied to woven wooden frameworks in a technique known as daubed earth, or compacted layer by layer to form solid rammed earth walls. In other cases, soil materials are processed into bricks, roof tiles, or wall tiles. Clay-rich soils are shaped into bricks that are first air-dried and, in many cases, later fired to increase their durability. Sand and gravel are commonly used in foundations or mixed into concrete.

To improve the quality of locally available soils, builders traditionally adjusted the composition of loam by adding mineral or organic materials. Organic additives such as straw or other plant fibres were also commonly incorporated to stabilise the material, reduce cracking, and improve thermal insulation.

Earthen techniques can be broadly grouped into three categories: (i) monolithic construction, such as rammed earth walls formed by compacting moist soil; (ii) brick construction, using air-dried adobe bricks or fired clay bricks; and (iii) hybrid systems that combine loam with structural frameworks made from wood or other materials.