They are using nothing but earth, water, sand bags and barbed wire (and 10% cement in CA to meet regulations) to make homes in 22 countries throughout the world. They have been tested and were so earthquake safe that they broke the machines used to test buildings. And while the ones the kids are standing in front of here are more like huts than homes, we saw some that were amazing; kitchens, bathrooms, garage, the works. One was bigger than our house. The smaller ones can be built in a day and they are incredibly inexpensive to make. If I remember right, the largest one only cost 5grand and my family could live in it very comfortably. My children were asking if we could move in! (I wish I had taken a picture of it!)
This is how it is done. They take long sand bags and fill them with a mud mixture then tamp it down until it is hard. Lay barbed wire over the top and then another bag. Then when the building is complete it can be covered with a mixture of earth and water to give it a smooth finish.
This is the inside of one of the buildings left without the finish to show how it is done. It's like a giant coil pot!
The children were allowed to climb all over them afterward and let me tell you they thought that was the coolest thing ever. "You mean we can climb on the buildings?"
It was so much fun to see some of the things we have been learning about, domes, arches, etc, put to a practical and worthwhile use!