What is an earthbag? Well, simply put.. it's a bag filled with dirt, sand, gravel, or any number of other readily available materials you might find lying around outside. Although this may sound like a primitive way of constructing a home, the simplicity of this technique brings with it a number of advantages which make it an idea worth spending some time on..
For a long time, bags of earth have been used by the military to create durable, weather, earthquake and bullet resistant barriers to protect soldiers in times of war, but were now beginning to understand the power of earth to provide us with sustainable and efficient shelter which can protect us from the elements of nature in our daily lives.
One aspect of earthbag homes which particularly stands out is the fact that the bags can be stacked in virtually any arrangement, including a dome form; this is important because in areas where wood or metal beams may be hard to come by, a fully enclosed and structurally sound building can easily be constructed without the support of any internal tensile materials, and with very little building skill. Earthbags, depending on what materials they're filled with, also have the potential to either insulate a structure, or provide thermal mass which can effectively store heat and stabilize the internal climate of a building.
I came across a non-profit organization called Cal-Earth (www.calearth.org) who specializes in educating people on how to build earthbag homes, and even offers courses which teach the fundamentals of this innovative approach to sustainable architecture. The video below gives a glimpse into the construction process involved in building one of these homes, and also offers some insight into the philosophy behind the Cal-Earth organization.