Earth Architecture
Buildings made with earth are economical, energy-saving, environmentally-friendly, and sustainable. Earth architecture includes adobe, cob, straw, and compressed earth blocks.
Compressed Earth Block
Compressed Earth Blocks, or CEBs, are construction blocks made with clay, sand, and a stabilizing ingredient such as lime or Portland cement. The earth mixture is poured into a hydraulic press machine. Since they are machine-made, compressed earth blocks are uniform in size and shape.
Cob Houses
Cob houses are made of clay-like lumps of soil, sand, and straw. Unlike adobe and straw bale construction, cob does not use bricks or blocks. Instead, wall surfaces can be sculpted into smooth, sinuous forms. A cob home may have sloping walls, arches and lots of wall niches. They are one of the most durable types of earth architecture. Because the mud mixture is porous, cob can withstand long periods of rain without weakening. They are suitable for the desert or for very cold climates.
Earth Sheltered
Earth sheltered, or underground, houses lie mostly beneath the ground surface. The surrounding soil provides natural insulation, making these houses inexpensive to heat and cool. The best location for an earth sheltered house is on a well-drained hillside. Windows facing the south or an overhead skylight will fill the interior with sunshine. Earth sheltered homes are typically made of concrete. Construction costs can run 10% higher than that of a conventional house.
Straw Bale
In the African prairies, houses have been made of straw since the Paleolithic times. Straw construction became popular in the American Midwest when pioneers discovered that no amount of huffing and puffing would blow down hefty bales of straw and grass. Modern day “pioneers” who are building and living in these homes say that building with straw instead of conventional materials cuts the construction costs by as much as half.
Rammed Earth
Rammed earth construction resembles adobe construction, but since adobe requires dry weather so that the bricks can harden enough to build walls, in rainy parts of the world, builders developed “rammed earth” construction. A mixture of soil and cement are compacted into forms. Later, the forms are removed and solid earth walls remain. Rammed earth buildings are environmentally-friendly and fire and termite resistant.
Adobe
Adobe is a term widely used in the southwestern United States and Spanish speaking countries. Although the word is often used to describe an architectural style, adobe is actually a building material. Adobe “bricks” are usually made with tightly compacted earth, clay, and straw. However, construction methods and the composition of the adobe will vary according to climate and local customs.
