Toward Sustainability: Straw Bale Houses
Reprinted from the Mensa Bulletin
By Mary Jo Ballator ©2004
When I tell people my house is made of straw bales, their first question, after they joke about the wolf blowing down the house is, “How long will it last?” I answer that I expect it to last as long as any conventionally built house.
Why did I build with straw?
The current straw bale revival had its roots in the Sand Hills of Nebraska just after the invention of the baler in the 1880s. As settlers moved into that area, they found that the soil was too sandy for building the temporary “soddies” that were used elsewhere. Wood was scarce and generally had to be imported from the east. Stacking the baled prairie grasses and improvising a roof to cover the bales afforded them quick and inexpensive shelter. As they discovered how comfortable these houses were in winter and summer, they plastered the walls to make them last. Many of those early houses are still standing and are well over 100 years old. Where the integrity of the plaster has been maintained over the years, the bales have remained protected from the elements, and the houses are as sound today as when they were built.
Straw bales are too tightly compressed to support combustion, and termites prefer eating other things.
The insulation factor of straw is superb. Studies vary from R33 to R60, depending on what kind of straw is used and how it is baled and stacked. The straw itself acts as a thermal mass, taking hours or days for outside heat or cold to move through the wall to the inside of the building. My house’s passive solar design warms it in winter. It takes two or three cold, cloudy winter days to cool the inside to the point of needing auxiliary heat. Even with snow on the ground, the sun coming through the south-facing windows will generally warm the house to an acceptable temperature.
Straw bale houses can be built in any style, from the most formal to the most organic. They can be inexpensive to build if the owner can do most of the work him/herself, or as expensive as any custom-built home. They can be load bearing (roof weight resting directly on the bales), or post and beam (roof weight resting on posts). Many states now have straw bale building codes. Insurance carriers are used to insuring these structures and the premiums are no more than for a conventional house.
Inside my house it is quiet, it feels solid, and it has the added benefit of using natural materials that do not release toxic gases into the indoor air.
Perhaps the most important reason I chose straw is its sustainability. Straw is an annually renewable resource, and except for use as animal bedding, it is largely a waste product left over from the growing of grains. Farmers are glad to find a market for it. Today, while many natural resources are in diminishing supply, straw remains inexpensive and abundant. Its use saves other resources directly and indirectly. In most areas of the world, there is a local supply, making it an excellent material for use in developing nations or in times of natural catastrophe for emergency housing. Living in a straw house makes me more aware of using precious natural resources. I use less without having to sacrifice my quality of life. For me, it has been a small step in the right direction.
If you would like to learn more about sustainable technology and practices, we hope you will plan to attend the next Mensa Colloquium: Earth in Mind: Fueling the Future in Tucson, Arizona, March 4 – 6, 2005. You may get additional information and register on line at http://colloquium.us.mensa.org/.
Mary Jo Ballator
Program Co-Chair
Colloquium 2005
2mjb at mindspring dot com
Copyright © 2004 Mary Jo Ballator. All rights reserved
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