Part of the Walipini build is the design. This plan is not an instruction manual, just the measurements and general layout to be followed during construction. If you’re looking for a resource about all the ins and outs of earthbag building, avail yourself of Earthbag Building: The Tools, Tricks and Techniques (Hunter and Kiffmeyer, 2004), which you can find on Amazon or in pdf for free here.
This design shows the relative size and shape of the structure. Corner to corner measures 15 × 8 ft, but each wall bows about 1–2 ft to take the lateral pressure of the bermed earth. It is dug down 2 1/2 ft. The excavated soil will form the berm around the structure as well as the fill for the bags. It will require about 500 55-lb poly bags. Each outside wall is surrounded with clear 4-mil poly to keep moisture on the outside. Additionally, most of the bags contain an inner plastic liner to further isolate the fill from moisture. As we’re using an unusual mix of clay and straw, we’d like to keep the fill’s moisture content as constant as possible.
The roof is built of 2-×-6-in rafters secured to a top plate and braced with earthbags between them. The rafters will be covered with corrugated clear poly sheeting to protect the inner glass layer — attached to the underside of the rafters — from hail. This creates an air space for additional insulation. A gutter on the low side will move water away from the structure.
At the southern end is a 1-ft-deep cold sink, which allows the coldest air to, well, sink away from plants on the upper floor. This is a design feature of igloos and other cold-weather architecture.