“Earthen Hand Natural Building recently has created an 800 sf earthbag house on the Olympic Peninsula in Washington state. Passive Annual Heat Storage (PAHS) design features were used in this building, giving it the ability to heat and cool itself passively using the earth beneath the building and the walls themselves as a battery of heat. This technique has been around a long time and has produced some amazing results. This building will also incorporate a south-facing greenhouse, greywater system, and solar.
A standard rubble trench foundation with gravel-filled poly bags was used, and the mesh bags or ‘hyperadobe’ were used in the majority of the wall. We used individual bags and not continuous bag on this project. These bags are similar to onion bags and they allow the fill to squish out of the tiny holes so that the clay of one bag sticks to the others around it with considerable strength. The hyperadobe technique eliminates the need for using barb wire, and instead we added borax-soaked bamboo stakes in every bag for earthquake insurance.
PAHS design involves the addition of sloping underground sheets of plastic diverting all water away from the base of the building, which keeps the soil around and under the building dry. Because it is dry we can store the excess summertime heat in the soil to be released in winter. Two air tubes wind underneath the berm that is built around the house. The air is moved by convection and the tubes bring in cool fresh air in the summer and warm fresh air in the winter.”