Our roundhouse is nearly finished and so I wanted to share some results. The main impression is one of incredible fortresslike strength — massive walls with no sway. Our roundhouse and dome are probably the two strongest buildings I’ve ever worked on. Our earthbag dome, for instance, never budged as about 15 truckloads of soil were dumped on top (and remains in perfect shape in a rainy climate two years later).
It boggles the mind how flimsy stick-built houses meet code and yet some have doubts about earthbag building. Let’s briefly compare the two: A strong person could readily kick their way through pressed board siding and sheetrock (typical materials in stick framing) in about one or two minutes. The same person would probably be struggling an hour later trying to penetrate an earthbag wall, even with a sledge hammer, pick, shovel and crow bar.
I’m trying to find the best way to convey just how strong earthbag building is. There’s a good example on page 21 of Donald and Kaki’s book Earthbag Building: The Tools, Tricks and Techniques. They show photos of an earthbag privacy wall that was hit by a drunk driver. The wall was relatively undamaged except for some chipped plaster, while the car was totaled.