When considering ecologically sound construction methods and materials, few if any have as many layers of redeeming value as straw-bale construction. The raw material is 100% waste of another industry, the growing of grain for food, and in many cases is otherwise burned, causing serious pollution. The material is packaged in a convenient and user-friendly form. The substitution of bales for lumber can relieve the pressure to log old-growth forests, preserving ecosystems for wildlife habitat, air-quality and soil-stabilization. Additionally, building with straw results in net-carbon sequestering, critical as we face growing carbon driven climate change.
Straw-bale construction is a proven durable method. Homesteaders in the Great Plains started building with bales in the late 1800’s, and many of these structures still stand today. Properly built and maintained, straw buildings can have a useful life span of at least 100 years.
Straw bale construction places all of the wall elements in the right location for high thermal performance: a protective layer on the outside, ample insulation at the center, and thermal mass to the interior. Unlike similar foam-based wall system, the bales are natural, healthy and rapidly renewable. When laid flat and stacked like bricks in a ‘running bond’ pattern, a plastered straw-bale wall is ±27" thick. Stacked ‘on edge’, with straw parallel to the plane of the wall, an R-30 insulation level is achieved in 25% less width (±18"). This is several times the value of typical insulated wood wall. The cost of construction with straw-bales is comparable or less than other thick-walled construction systems. When energy savings over time are factored in, straw-bale is the economical choice. One family in California's hot Central Valley was able to obtain a higher mortgage for their straw-bale home by showing that their cooling costs would be substantially less.
Straw-bale can have great aesthetic value, and lends itself to a variety of styles and finishes. The thick walls present opportunities for niches, deep windowsills and seating areas, and “truth windows”. And, as Matts Myhrman once said, "You can do anything with straw-bales, except have skinny walls!"