Earthbag House in Austin

Louis Burns, a writer and former real estate agent, toured a newly completed Eco-dome in Austin and wrote an eye-opening assessment. Here are a few quotes from the article.

“The plans from Cal-Earth that they’re working from are designed for the desert climate. There, you have a significant temperature drop in the evenings which allow the day’s heat gain to be dissipated out. Here in Texas, it only drops 10-20 degrees in the evenings during the summer so once the house gets hot, it will stay hot. So those plans weren’t designed to be used in Texas.

Cal-Earth didn’t mention that fact nor that the plans they bought would have to be stamped again by a licensed architect/engineer in Texas. Turns out that not only were they not supposed to use those plans but those plans were for educational purposes, not actual building.

I don’t see how the bubble alcoves are going to work for bedrooms though. Maybe that’s why they’re labeled bedroom-niche on the eco-dome floor plan. To walk inside one, you feel there is a lot more space above your head than around you. I’m not sure even a twin bed would fit in one. They’ll definitely fit a half bath though.

I took a picture of one of the bubble alcoves but I couldn’t really get a good angle on it. It’s kind of like walking into an elevator with enough room to move to the side and then turn around and wait to get out.

Low arched doorway rebuilt to meet code
Low arched doorway rebuilt to meet code

Another planning issue was the doorways. To meet code here in Austin, they need 6’8″ rectangular passageways. The arches weren’t tall enough so he went back, knocked the top of them out and set concrete in them. He couldn’t build arches that tall because then you get into doors that don’t fit the slope.”

You can read the entire article at Austin Tiny House.
Earthbag House website

8 thoughts on “Earthbag House in Austin”

  1. I will be in Austin the weekend of March 10th and would love to be able to see the work you have done. I am in the design phase for a home in Oklahoma.

  2. I read the entire interview, and while I did not attend the open house, I can see, based on the interview, that they made some mistakes in the construction, but that they found some solutions to handle them. One thing I might suggest is that, due to the lack of extreme day/night temperature swings, that they find a way of insulating the outside of their bags. Preventing heat from reaching the thermal mass would be less expensive than adding refrigerated air conditioning.

    There are several ways of doing this insulation layer. The quickest way would be to spray expanding urethane foam on the outside, and then finding a way of coating it to prevent UV degradation. Another way would be to create another layer of bags filled with an insulating material, such as rice hulls, pumice, etc. These bags wouldn’t need to be as wide as the original layer of dirt/clay filled bags. These would also need to be plastered over.

    I noticed in the expanded review that they did not use barbed wire during construction of the domes. It was noted that this created a problem of bag slippage which was corrected by the use of rebar. Even though they do not live in an earthquake zone, the barbed wire is important.

    • Yes, insulating the exterior is a good idea in hot climates, especially domes since they are in direct sunlight (no protective roof).

      The story does a good job of getting people to think through their situation. Every job will have challenges.

      Building domes without barbed wire is risky. The larger the dome and the more rounded it is the greater the risk.

  3. This is an idea that many people have difficulty grasping about earth building. That there is is no one size fits all design. Each unique place in the world offers unique challenges and solutions. The CalEarth Ecodome was designed for Monks, whose needs are a bit different from the typical western family.

    I think the plans main use is as an example to show building inspectors that this building system works and has been approved in some of the toughest building codes in the country. It sets a precedent. For a person building in a code restricted area, use these plans as evidence, and if you need engineering done, is licensed in many states. Design for your climate and your needs. There will never be a stock plan that can truly fit to your lifestyle and needs. We are unique, and come in so many varying shapes and sizes, there really is not a one size fits all when it comes to clothes, or the buildings we live.

    The EcoDome is a beautiful and simplistic house, that could be functional for the right person. I don’t think it will be the new rage on the housing market, and it wasn’t meant to be. I know from having built one, that I’d rather be in an ecodome, warts and all, than most rectangular stick houses available.

  4. I’m in Texas, too, but not near Austin. I’m in the high desert in the far west. I’ve lived in the typical central/south Texas climate, though, and agree that, during the summer, the temperature drops at night are only 10 to 20 degrees and sometimes, it can be 85 degrees at midnight. Am I wrong to assume that open rooms with few or no interior walls will solve some of this temperature problem? And even though this is not a sustainable solution, couldn’t these Austinites run air conditioning or some form of cooling during those limited days and still save money and resources due to the building method?

    There are a few main reasons why we chose to go with an Earthbag dome (which, for the record, is only at the foundation stage until I can take off work and we can get back to our remote property). They are 1) ease of DIY building and low learning curve, 2) low cost of materials, 3) not having to haul wood and other non-sustainable materials to our homesite, which is an hour from pavement and over rugged country, 4) ability to use manual building methods with little or no machinery, 5) the flywheel effect, and 6) aesthetics – we think these buildings are beautiful.

    I hope you will comment on the Austin home reviews. Thanks.

    • Gwen, You’ve made lots of good points that I agree with. The author of that article was offering a critical review — pointing out some of the downsides — of one particular home. This is good information that can help prevent similar problems. But yes, in general, you’ll be far ahead in terms of comfort and saving money with earthbag instead of stick frame.


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