HOUSE of STRAW
Contrary to what preconceived notions you might have about building a house of straw, straw bale homes are well-insulated, affordable, environmentally friendly with a small carbon footprint, and can be aesthetically pleasing.
The bales themselves have low embodied energy from being an agricultural byproduct, and compared with conventional building materials, they take far less energy and time to produce and transport.
Building with the bales is conceptually easy-to-learn and can be a relatively simple process, since straw itself is flexible and quite forgiving, and it can be sculpted to fit desired designs and styles.
Although it seems counterintuitive, straw bale construction is far more fire-resistant than conventional stick-frame homes, since the densely packed bales severely limit the flow of oxygen, and the plastering in the construction process renders fire risk even lower.
Photo by TTFC
The view from inside (top) and in from outside a house in progress.
As far as starting materials go, the only primary needs are compacted straw bales for the structure and insulation, clay or other plaster to seal and surface the walls, and roofing materials.
From there, the home itself will be effectively built and all that is left is to fill it in — windows, doorways, other architectural touches, all of which can be easily done with a knife or chainsaw.
Although there are contractors who specialize in such construction, the concept and procedure of building with straw bale can be understood by novice homebuilders, who can then assist in the process with a supervisor.
This way, the homeowner can save some expenses with the occasional hand from friends and family.
Photo by Kayla M.
Some useful tips and things to keep in mind:
• Bale quality is critical. Look for bales just after harvest around September, and see that they are densely packed, ideally long straw fibers that are tied with rot-resistant polypropylene twine.
• Direct contact with the ground is essential to maintaining cool temperatures in the summer and heating the home in the winter.
• Pests are always a consideration with any home — except these. Holes, nests, and food are the main requirements for pests, and plastered bale homes provide none of these. Even termites don't like straw!
• Small voids in the walls, which are inevitable, are easily filled with a dry straw and clay, with a plaster finish.
Photo by Cadmon
Photo by G. Grimm
Adding clay plaster to the exterior of a straw bale home.
In straw bale homes, function meets beauty.
Photo by Kayla M.
Most importantly, with effective R-values of 40 to 60, straw bale insulation is most effective in Wyoming’s climate, where keeping the house comfortably warm or cool is critical.
The characteristically thick walls carry a passive solar building effect of absorbing energy and storing it for future release. This means that indoor temperatures remain more comfortable in winter and summer.
Best of all, straw bale homes go up rather quickly, so the payoff is that much sweeter.
Photo by SLT
USEFUL REFERENCES
Stories and an insightful guide for a DIY straw bale home from a senior couple who built their own home for under $30,000.
The Last Straw is an international journal of straw bale and natural construction that includes diverse articles about projects and up-to-date techniques, "written by and about those who design and build with natural materials, research them, live with them—and just plain love them."