ECONEST: Creating Sustainable Sanctuaries of Clay, Straw and Timber by Paula Baker-Laporte and Robert Laporte.
Light clay, straw / clay, light earth or leichtlehm is a natural building material consisting of straw and clay, as you might suspect from the name. The straw is tossed like salad in a mixture of creamy clay slip. It is then stuffed in wall cavities surrounded by forms. As one coarse is filled and tamped the form work, usually a 4 x 8 piece of ply wood is removed and leap-frogged above the next ply. At the end of the day the forms are removed and the wall is allowed to dry, sometimes for as long as a year. When dry the walls are covered with an earthen plaster or wooden cladding. This material is used as an infill only; it is not a load bearing material. It is a great material to use in combination with timber-framing as Robert and Paula have illustrated in the EcoNest designs.