Our blog has quite a few free emergency shelters for various purposes. All designs can be found on this blog using the built-in the search engine. Free detailed plans for these shelters are on our Free House Plans page. I’ll add this latest design there if it proves popular. Leave a comment below if you’re interested in building this earthbag shelter.
This emergency earthbag shelter is designed for those who need temporary shelter, such as those who have suddenly lost their job and home. You may not need something like this now, but it’s always good to have backup plans just in case. This earthbag shelter is also suitable for developing regions, as a storm shelter, root cellar, seed storage, tool shed, quiet space, etc. It can be built in two or three weeks by one person, and is extremely low cost. The diameter and height can be adjusted to suit your needs. Almost no purchased materials are necessary. As one example, I suggest recycled feed bags from farmers or feed stores, or mesh produce bags from farmers markets. You can use galvanized wire for tying bags closed (about $2 for small quantity), salvaged rebar from a recycling center (cost varies), and 6 mil poly sheeting for waterproofing. Gravel or sand/gravel mix for lower courses could be obtained from a nearby gully or stream bed. Your mileage may vary, but I estimate the cost at around $200-$400 using the tips outlined here.
Roof: The reciprocal roof (more details below) consists of round poles (free from a forest) or rafters of milled lumber covered with decking material such as rough sawn lumber from a local sawmill, pallet wood (free) or small poles (free). The top is covered with several layers of 6 mil black poly plastic sheeting that extends beyond the walls about 8 feet or so to direct water away from the building, and then soil and plants added to create a living roof.
Bond beam: Emergency shelters with low walls such as this don’t need bond beams. The earth berm around the sides and vertical rebar pinning that secures roof poles would prevent the walls from spreading outward.
Soil for the earthbags, berm and living roof: I would build on a naturally occurring high spot. This would minimize excavation work and/or transport of soil, which is the hardest part. (I’m assuming the shelter will be built in a roadless area where trucks can’t get in.) Dig out the center and use the excavated soil in the earthbags and for the living roof. If trucks can get into the area, then great. It’s far easier to work with loose soil than dig it out of the ground by hand. Dump the soil next to the building site in 2-3 piles to reduce labor.
Other advantages of this earthbag shelter:
- Almost completely invisible once built.
- Small enough to be built under a tree canopy to help avoid detection.
- Extremely energy and resource efficient. Add some scrap foam board insulation around the outside of the earthbags in cold climates.
- This shelter could be heated with a tiny fuel efficient stove such as a rocket stove. (See Small Wood Stoves for Small Homes)
- Low cost floor options include tamped earth, gravel or pallet flooring. Don’t laugh, but a few layers of corrugated cardboard on top of pallets would work great. Our dog had puppies two weeks ago and we improvised a very cozy shelter out of cardboard. I stuck my hand inside early in the morning to check the temperature and was surprised at how warm it was with the dogs inside.
- Arched doorway is strong and requires no lintel. Use tires or a barrel for forming the arch.
- Use large enough diameter roof poles and you could add 1-2 feet of soil on top to survive most anything that might come your way.
- There are no windows, so you’ll want to build a cupola with screened openings for light and fresh air. Run the stove pipe out through the cupola.
What is a reciprocal roof?
“A reciprocal roof is a beautiful and simple self-supporting structure that can be composed of as few as three rafters, and up to any imaginable quantity (within reason, of course). Reciprocal roofs require no center support, they are quick to construct, and they can be built using round poles or dimensional lumber (perhaps with some creative notching). They are extremely strong, perfect for round buildings, and very appropriate for living roofs, as well. The reciprocal roof design was developed by Graham Brown in 1987.”
Source: Check out Ziggy’s Year of Mud Blog – How to Build a Reciprocal Roof