How to Build an Earthbag Roundhouse

How to Build an Earthbag Roundhouse


Due to the enormous popularity of my first earthbag instructable, I’ve added a new one about building roundhouses. This is the most comprehensive earthbag roundhouse information published anywhere on the Internet, with step-by-step directions and lots of photos.

“We built this earthbag roundhouse in 2010 as part of an earthbag workshop in Thailand, and finished it later that summer. Roundhouses are perhaps the simplest, fastest, easiest earthbag structure to build. We’re extremely pleased with the results, especially in terms of strength and cost. This is one of the strongest structures I’ve ever worked on in my 30-plus year construction career. The main impression is one of incredible fortresslike strength – massive walls with no sway. I’m sure it could easily withstand a direct hit by a speeding vehicle. This is no exaggeration. There’s been at least one incident where a drunk driver hit an earthbag wall and only chipped the plaster. (The vehicle was totaled.) Earthbags also excel at withstanding floods, hurricanes, tornadoes and earthquakes. Engineered plans are now available for whatever conditions you face. Earthbags are even bullet resistant, as explained in our highly popular blog post where compressed earth withstood 50 cal “BMG” 661 grain Full Metal Jacket rounds. Bullet Resistance of Compressed Earth.

The other key advantage of earthbag is cost. For our roundhouse, we wanted things to look nice, of course, but we didn’t want to spend a fortune. The final cost came out to $11.50/square foot. Most stick-built houses are $100/sq. ft. and up, so this roundhouse demonstrates how anyone can build their own home even on a very tight budget. We used a few basic, low cost methods to class up the roundhouse: rounded window and door openings (free), nice colors (no extra cost), curved bathroom wall and buttress (no extra cost to create curves), exposed wood and thatch roof (dirt cheap), earthen plaster on the interior (really dirt cheap), and lots of beautiful old windows for views, ventilation and to add a sense of spaciousness. In summary, build small — just what you need, use simple shapes, pay with cash, and add on later if needed.

Basic project information:
18’ exterior diameter; 15’ interior diameter; 177 sq. ft. interior floor space; total cost of materials: $2,045, which is about $11.50/square foot

You can read the entire step-by-step article free at Instructables.com.


Comments

Instructable: How to Build an Earthbag Roundhouse — 9 Comments

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    • That’s one of the best roof building methods. I haven’t built one yet but would love to try it. I would have built a reciprocal roof on our roundhouse except we don’t have lots of long straight poles. The compression ring that we used worked perfectly.

  3. Beautiful house. I was wondering where you sourced the compression ring? What is it made of and how do you know when it is strong enough? Thanks

    • I had it fabricated in a local metalworking shop. It’s easy to make with the right machines (which cost many thousands of dollars).

      Like most experienced builders, I can look at something and tell you if it’s strong enough. That approach works fine if there are no building codes. In code enforced areas, you’d have to get an engineer to analyze the loads.

      The compression ring is made with two pieces of steel. One is simply a 3″ wide strip of metal bent into a circle and welded at the end. The other piece flares out at angle just like a skirt. That’s the tricky part to make. Weld the two pieces together, drill holes and spray paint it. Total cost about $25 in Thailand.

  4. Wow, this is really amazing. The quality of information out there on DIY earthbag building is truly stunning. Thank you for yet another wonderful contribution!

    • Great! That’s what I want to hear. That’s why I’m making these Instructables. It breaks things down into clear steps so people are more likely to use the information. I’m working on an earthbag dome Instructable right now.

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