What makes rammed earth sustainable?

From an environmental impact and sustainability point of view rammed earth can have many advantages over other current building practices.  When appropriately designed and constructed, a building made of rammed earth should have a functional lifetime greatly exceeding that of most contemporary structures.  Rammed earth’s performance characteristics will lead to lower energy usage in heating and cooling costs. 

Rammed earth outperforms concrete from an environmental viewpoint.  With similar structural characteristics rammed earth contains 6% portland cement compared to concrete’s 20 to 30%.  Portland cement is an excellent structural material, however its production is very energy intensive and its use should be minimized whenever possible.