Why are most houses made of wood? Among other reasons, wood is inexpensive, durable, and readily available. But wait, lots of raw materials are inexpensive and durable and readily available. Rocks. Clay. Bamboo. And, in agricultural areas, straw.
Humans have been building houses out of straw for thousands of years. The material lost favor to wood as methods improved for felling and processing lumber, but now it’s trying to make a comeback. Strawbales can produce strong, durable walls with high shear strength, inherent insulation, and far better fire protection than lumber. (Surprised? A well-made strawbale is packed so tight that oxygen can’t pass through, meaning a fire can’t spread.) Best of all, straw is a byproduct of farming, thus making the bales friendly on both your wallet and the environment.
This website tells you all you ever wanted to know about building with strawbales. The author, Andrew Morrison, is something of a strawbale genius: he has dozens of builds under his belt and hosts instructional workshops around the world. I love the flexibility of the material and the casual curving shapes that are possible. With a plaster finish, the structures are totally watertight and can resemble adobe dwellings characteristic of the American Southwest.
Strawbale construction has serious limitations. You can’t span any appreciable distance with bales alone, so you’ll need to incorporate materials that work in bending to support a second floor or roof. (This engineer thinks a strawbale-only structure, using arches for pure compression, would be a fun design challenge.) More practical concerns, at least around here, are permitting and constructability. America abounds with carpenters, but few builders are familiar with strawbales, and few jurisdictions have adopted a code for this type of construction.
If you want a strawbale house, your best bet is to move somewhere that it’s legal, then take a class and learn how to build one yourself. This building method is no silver bullet, but it’s a very cool (and environmentally conscious) alternative.