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Straw Bale Building Goes Mainstream

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Building houses out of straw is as old as, well, as old as the medieval nursery story about the Three Little Pigs, and their houses; one of Bricks, one of Straw and something… it’s been a while.

Straw building has a long long history. It is a great natural insulator. But it’s not so easy for the average builder to access straw, these days.

You’ll not find straw insulation at your local hardware store.

Here’s a great solution for that. The US company Strawjet has designed machinery like the machine that makes Christmas trees easy to transport from the Christmas tree lot. Now we can simply wrap up our own straw bales so they can be handled as easily as sheets of plywood and sheet rock.

Any kind of waste grain stalks such as wheat and rice straw work well. You can also use tobacco stalks, hemp, sunflower, and Jerusalem artichoke, bamboo, palm fronds, river reeds, and wild grasses.

You can use anything for the binding cable; photo-degradable nylon or natural strings such as hemp, jute, or cotton. You can use the bales single file within prefab metal as here, or you can use it traditional style in larger packs.

The three major benefits of the system:

1. By reusing waste you avoid the carbon emissions of burning it.
2. This replaces materials that take more energy to manufacture.
3. No glues and resins need to be added. The material is environmentally pure.
4. The resulting building saves energy long-term because straw is a great insulator.

It’s a flexible system. The machine can turn out the straw bales in different formations, to simply fill in single-file between lightweight metal studs for climates that don’t need that much insulation or in various thicker multiple packed bundles. Curved walls are also possible, according to the company.

Oh, and the three pigs story? I think of it as an ancient “best practices” warning about fire safety; a kind of primeval building code enshrined in fable.

Straw bale construction should be used as insulation under adobe, as in the American Southwest. Then straw compares favorably with wood for fire safety.

Images from Strawjet
Via Inhabitat