Affordable and Sustainable DIY Earthbag Homes
Earthbag construction (sometimes called sandbag construction) is undoubtedly one of the most practical and lowest-cost construction methods. First used by the military for building sustainable, bullet- and blast-resistant structures, this construction method has recently seen a surge of interest among DIY builders. Today, there are an estimated 1,000 to 1,500 earthbag structures, including homes, offices, shops, schools, temples, clinics, orphanages, and even ecovillages.
One of the strongest selling points is affordability. A simple earthbag dome, for example, using recycled grain sacks and dirt can be built for around $ 100. A larger and more comfortable house can be built for around $ 500 to $ 1000. The EarthDome House in Terrasante Village in Tucson, Arizona is just one example.
Dirt bags are ideal for homeowner-builders. The skills required for each construction step can be learned in a few minutes. It comes down to simply filling the bags with an appropriate fill material (usually subsoil or gravel) and tamping them solid. There is nothing simpler than that. Also, few tools are required: shovels, buckets, garden hose. The few additional tools required (tamper, slider) can be manufactured cheaply and easily.
Buildings with bags of soil are sustainable as they are made primarily of soil from or near the construction site. Earthbag domes require no wood, reducing pressure on our forests. Expensive concrete foundations are not required if you use bags filled with gravel. Additionally, these structures are safe, quiet, non-toxic, rodent-proof, and resistant to fire, hurricanes, and floods.
Energy efficiency is another great advantage in favor of building with bags. Huge earthen walls stabilize interior temperatures in hot climates. In hot and cold climates, soil bags can be filled with an insulating material, such as lava rock, pumice, vermiculite, or perlite. Some builders are experimenting with rice husks for insulation, which are often free to use. In general, lightweight insulating materials (such as those just mentioned) require much less work than rammed earth and provide comfort during the harshest winters or hottest summers.
Soil bags can also be used to create structures underground (root / storm cellars, etc.) or with earth berms, retaining and privacy walls, planters, furniture (recessed benches, etc.) and many other uses. Dirt bags are highly adaptable and work just as well for domes as they are for structures with vertical walls. They also excel at creating curved free-form structures.
As the construction of bags of soil grows by leaps and bounds, NGOs and other organizations are exploring their use as emergency shelters. Millions of victims of wars and natural disasters need low-cost housing and temporary shelter. More durable than tarps and more comfortable than tents, dirt bags work perfectly, as even unskilled workers can build their own shelters, all without destroying local resources.
