Earth USA 2011
One hundred twenty participants came from fourteen countries and presented papers on various aspects of earthen construction. At the conclusion of the Conference participants worked collectively to prepare this message summarizing information, opinions and conclusions:
Earthen materials are globally available. Usually it is the dry climates that are bring to mind Adobe, Cob, Sod, Rammed Earth and Compressed Earth Blocks. However new locations for earthen buildings are always being reported. This year the surprise came from Norway where historical adobe homes are located near Oslo. Other reports came from China, Bulgaria, England, Oklahoma and Texas. Often these reports are of a few, isolated instances of earthen buildings. Germany, however, has long been known to have at least two million earthen homes.
Earthen homes are appropriate across the spectrum of building costs. Homes are built at zero cost in some countries while in places like New Mexico and Saudi Arabia contemporary adobe is considered the premium building material for homes and monumental buildings. Several papers at the Conference dealt with innovations that can reduce building costs in those areas where labor is expensive. In other parts of the world, labor is less expensive and employment is a sought after opportunity for citizens. Working with earth can create new jobs for young and old. It is richly intergenerational and educational in nature.
Materials costs are not tied closely to the petrochemical industry. In New Mexico, the cost of an adobe brick has doubled in thirty years while the cost of a 2 x 4 wood stud for frame construction has increased five-fold in the same period.
It must always be remembered that of all building materials, those of earth have the least embodied energy; their carbon footprint can be almost zero; and they are the most easily recycled, reused, repurposed or just plain returned to dust. Brown is the original green, the original back to nature.
Other authors reported on the efforts to codify the use of earthen materials in construction: There is much collaborative effort across the globe which also includes educating code writers and enforcers. Germans lead the way with thoroughly embedded building construction norms in their national codes which will soon be inserted into the European Union standards. Australia, New Zealand and the United States follow right behind. In the USA, adobe is now part of the 2009 International Building Code beginning with 2102.1 where it is defined. There is also The American Society for Testing Materials ASTM E2392, Standard Guide for Design of Earthen Wall Building Systems. Adobe is included in the Construction Specifications Institute system as 04 24 00, Adobe Unit Masonry with two subcategories, 04 24 13 Site Cast and 04 24 16 Manufactured. This means that earthen materials are now mainstreamed in the eyes of codes and standards.
Participants noted that earthen materials have cultural connotations. They are simply part of the lives of many cultures. While abandoned in many areas, there is a growing interest on the part of youth. New communities using earth as the basic building material are being created in Australia, New Zealand, Saudi Arabia and the United States. Most of the world requires great effort on the part of proponents of earth materials to preserve buildings from destruction in the face of modern development. Saudi Arabia has banned the further destruction of any earthen buildings of antiquity as a fine example to the rest of the world.
Architects, builders and dwellers have long had spiritual connections with the material and there are those who feel it creates living structures, certainly healthy structures without any of the chemicals often found in the modern home. The walls stabilize temperature and humidity through their thermal mass and porosity which promotes breathability and even phase change action as moisture moves in and out of walls.
Earthquake resistance is always a concern. Correct and careful building techniques go a long way to make any building safer. Age-old and new techniques can be incorporated in the design or retrofit to existing structures to increase their safety. Earthen structures are adept at resisting cyclones, tornadoes, hurricanes, fires, bugs and even bullets.
While all this is as old as dirt, it is as new as the next idea. Architects, designers and youth should be encouraged to create new shapes, forms and methods to create structures of wider appeal to more people. It need not be limited to the warm, round, brown buildings often brought to mind by the Santa Fe/Taos/Pueblo style; thoughtful, good design can increase its appeal while still maintaining timelessness.
After all, this is Planet Earth.