Building Your House from Straw
By adam bodendieck
June 23, 2010
I blame the three little pigs.
Whenever I’m discussing the concept of straw bale building with someone, they invariably bring up those famous pigs, and who am I to argue with fairy tale wisdom?
But here’s the thing: Straw bale building should not be confused with merely building a house out of straw anymore than building with lumber and timber should be equated with simply building out of sticks.
The basic idea of straw bale building is this: Instead of constructing houses from traditional materials, an efficient and environmentally friendly method can be employed in which straw bales finished with plaster and supported with timber or rebar frames serve as the walls of the house. And while many are hesitant to get onboard with the idea of building with straw (again, I blame the pigs), the benefits are both plentiful and obvious.
Not only is straw an abundantly available renewable resource, but straw bale houses can be built more affordably than traditional dwellings. In addition to material and labor being more affordable (provided you’re willing to put some sweat equity into the project), houses can be built in stages and added on to as resources allow—certainly a better option than taking out an overwhelming mortgage and racking up hundreds of thousands of dollars worth of debt. As a point of reference, and keeping in mind that building costs vary greatly across the country and can be much higher or lower depending on scale and the involvement of a contractor or paid laborers, one recent building project detailed its construction costs through every stage of the process and totaled $88,000. This included peripheral tasks, such as drilling a well, site preparation and septic tank installation. Also worth noting is that the house was built completely to code.
Another thoroughly documented project calculated total building costs at $51,450, or $37 per square foot based on exterior dimensions of 1,200 square feet. And while some claim it’s possible to build a home for $5-10 per square foot, many professionals disagree and assert that doing so would involve cutting many corners and would not be worth it in the long run.
There are even greater savings beyond the initial construction costs. Straw bale houses are marvels of energy efficiency, with well-designed houses capable of consuming approximately a quarter of the energy of conventional houses. Straw bale is a good temperature regulation system, able to retain heat during the day and release it at night. With the proper planning, it would be relatively easy to design a house in such a manner that the climate could be naturally controlled. According to Community Development and Sustainable Design professional Timberly Hund, a well-planned and constructed straw bale house can guarantee excellent performance over the years.
“People don’t build conventional houses because they’re interested in longevity or efficiency,” she says. “They build them because that’s what they’re familiar with and used to. People are scared of new ideas in architecture, but with a little bit of researching it becomes clear that straw bale building is perfectly viable, not so much a risk as just not yet common. The savings in heating and cooling alone can be phenomenal.”
One of the less tangible but no less important aspects of straw bale building is that, when all is said and done, what’s created is much more than just a living space. “It’s about more than just architecture. It’s about community,” Hund says. “Not many people are qualified to build a conventional house, but straw bale building invites everyone to participate. This is something you can do with your family, friends and neighbors, a way to create a real sense of community and ownership.”
Like with any major project, careful planning is required to ensure long-lasting success. However, most of the common concerns—such as the potential of fire, moisture and rot, and stability—can be easily assuaged.
Conventional wisdom would dictate straw is extremely flammable and therefore a poor building material. But controlled experiments have clearly shown that due to the tightly compacted nature of the straw bales, the walls are amazingly fire-resistant, withstanding 1,700 degree heat for more than two hours and surviving the subsequent hose-down. (For the record, that’s about three times the fire resistance of traditional houses.)
Moisture leading to mold and rot within the walls is a warranted concern, but also one that can easily be laid to rest. Straw is breathable, so even though the plaster used to complete the walls will absorb moisture, the walls are still able to breathe—meaning the moisture won’t sit and cause rot. As long as attention is paid to detail while building (including window trim, a good foundational slab and roof, and proper placement of the house to begin with), the risk of mold and rot is no worse than with any other type of wall construction.
That same diligent level of attention paid to detail will ensure a stable house. Provided you do some research and seek out the advice of a well-informed professional during the planning and construction stages, stability should not be an issue—even if a big, bad wolf tries to blow your house down.
There is one issue that can be slightly more problematic: zoning and code restrictions. It’s not a coincidence that most straw bale houses are built on their own land as opposed to in subdivisions. And while some states and counties are fairly lax in their building regulations, others are more restrictive and notably less progressive. (One of the more amusing scenarios involves a county in the Midwest that allows straw bale houses, but only so long as they’re registered as boat houses. It seems that the zoning commission is warming to the idea, but not quite there yet. What’s unclear is how many people have taken up residence in their alleged boat houses.) It’s important to be familiar with building regulations prior to beginning construction, and there are lots of resources available online for those looking to convince their local zoning committee that what they’re proposing is on the level and perfectly acceptable.
Straw bale building is not a new technique, but it’s one that’s just now starting to gain traction in mainstream circles. And as long as we can all come to terms with the fact the three little pigs’ woes stemmed more from shoddy construction and being neighbors with a wolf blessed with extraordinary lung capacity than with their choice of materials, the preference for this environmentally and socially responsible building method should only continue to grow.
“It strays from the norm,” Hund says. “But it’s about more than just architecture. It’s creative and engaging, it’s environmentally and socially responsible. More than anything else, it’s about quality of life.”