Additional insulation is usually not required. The virtually maintenance free walls require no energy intensive or toxic sealants, cement plasters, paints, sheet rock, or fire brick veneer to make them more attractive. Rammed earth walls are formed in place by pounding damp soil into movable, reusable frames with manual or machine-powered pneumatic tampers. Rammed earth has potential even in the coldest and wettest places in the United States, and because of the strength of the walls is great for multi-storied buildings. Plastered Straw Bale Plastered straw bale houses were developed in the late 1800's in the Nebraska Sandhills, a vast grassland area with limited trees.
Straw bales are an excellent building material.
Buildings almost one hundred years old are still in great condition. The energy efficiency of straw bale is two or three times greater than that of conventional housing. Straw bale houses are structurally sound, safe and economical. Recent fire studies from Canada, Arizona and New Mexico show that straw bale houses are more fire resistant than conventional wood frame houses. The plastered bales hold enough air to provide good insulation, but are firmly compacted and do not hold enough air to allow combustion.