Rammed earth is  a process of tamping earth into forms to create stone-like structural walls.    Rammed earth has been used for millennia to create long-lasting structures.  Sections of the Great Wall of China, over 2000 years old and running for hundreds of kilometres, are constructed of rammed earth.   Modern rammed earth, stabilized with rebar and a small percentage of cement,  impervious to fire and able to withstand hurricanes, floods and earthquakes, should easily last hundreds of years.

Building with insulated rammed earth meets all of the criteria associated with sustainability:

• locally available, abundant material – appropriate subsoil is found everywhere; a very small (five acre) gravel pit would provide enough leftover material (after the gravel had been extracted) to build 5000 homes
• does not deplete any natural resources – we currently clearcut over a million acres every year in North America to build houses.
• non-toxic – there is nothing organic in rammed earth hence nothing for moulds to grow on and no need for chemicals to combat moulds or fungi in the building materials.  Nor are there any other chemicals needed: no paints, drywall compounds or plastics.
• beautiful in its unfinished state – if a building is not beautiful, no one will want to live in it but every added step of finishing with a traditional build requires more energy to process, transport and apply.
• durable – rammed earth has stood the test of time: the Great Wall of China is only one of many ancient examples from all over the world.  The technological improvements of modern rammed earth will allow is to easily outlast current building stock by centuries, and in the process eliminating the stream of waste as houses need repair and replacement.
• energy efficient –In the occupancy stage, representing the vast majority of a building’s energy use, rammed earth truly shines.  The enormous thermal mass of the walls allows them to absorb and retain solar energy from south facing windows.  The house will literally heat itself and, if properly insulated, will stay warm.  In the summer a large overhang ensures that the walls stay cool.  Add a few solar panels and the house is net zero energy, for its entire lifespan.  If every house on the planet were built of rammed earth we could cut our fossil fuel use in half.
• feeds the human spirit – there’s something about rammed earth that makes it very calming.  Perhaps it is the solidity of the 18” walls, the natural surface, the quiet of the building, or some less definable qualities. If architecture is going to improve the human condition, rammed earth is an excellent starting point.