Why You Might Want to Build a House of Straw
Straw bales are cheap, easy to find and DIY-friendly. Get the basics on building with this renewable, ecofriendly material
I’ve often advised that to have a truly sustainable home, one must really understand the details of how a house works. As our knowledge about homes increases, so does our desire to get involved with the design and construction process. That’s where straw bale construction comes in.
The DIY aspect of straw bale is making it an increasingly popular construction material for family homes. The attraction, aside from the environmental and health benefits of the material itself, is that you can get your hands dirty and contribute to the construction of your own house together with your family. There’s something about being able to say, “I built this home with my own hands” that is incredibly satisfying.
The main benefits of straw as a construction material are: It’s cheap, it’s relatively easy to find, it has a low environmental impact, and it can contribute to healthier indoor air than many other materials.
It’s important to source your straw well. Remember that anything that straw was treated with may end up in your lungs. Truly sustainable straw is locally sourced from nearby fields that have not been treated with pesticides.
Before PhotoElectric Bowery
Straw that is suitable for construction can be harvested from a number of crops, so it is available in many geographic locations. Different kinds of straw have different properties. For example, rice straw is said to be more durable than wheat straw, because it has higher silica content.
The airtightness of your wall construction is of utmost importance. Leaks in the building envelope can cause warm humid air to seep into the walls, causing the straw to eventually rot. But remember, this danger is not only with straw bale homes. It’s a common problem in many standard homes, as seen in mold and condensation.
See more about indoor air quality
See more about indoor air quality
Before PhotoAMD Architecture
Depending on your local regulations, the bales themselves can be used as a load-bearing structure for the walls. Otherwise, you can use a wood or steel frame structure, with the straw acting as the insulation. In addition to the walls, straw can be used as insulation material for the roof.
The thickness of your wall will be determined by the baler machine that the farmer uses to collect the straw. Usually, the rectangular bales (circular ones won’t work for standard construction purposes) are about 18 inches (45 centimeters) thick. This makes straw bale construction particularly suitable to high-efficiency homes, and is even applicable in homes pursuing the Passive House standard.
While straw is a relatively good insulation material, beware that sometimes literature in favor of this technique tends to overestimate the quality of an average bale. Each and every bale should be inspected for consistency and integrity, and should be well dried out. That being said, a construction site full of dry straw can be quite a fire hazard. Particular attention needs to be paid to storage and access during the construction phase.
Once the finish is applied to the straw, whether it be in the form of drywall with a fireproofing layer or plaster, the danger is reduced and comparable to that with any other wooden home.
The type of finish you choose will make a pretty big difference as to the type of texture you’ll end up with in your house. Many choose to use clay plaster for the interiors, so that the organic and tactile nature of the straw comes through.
One of the aesthetic benefits of straw bale with clay plaster is its sculptural quality.
You can get inventive with shapes and forms of doorways …
… nooks …
… and niches in your walls.
With the plaster you can round off edges and create a very soft look while maintaining simple, clean, modern lines.
After its completion, it can be hard to tell that a house was constructed with straw, so many people leave a little window into one of the walls.
It’s a nice way to remind yourself of the work you put in, plus it’s a great conversation piece.
Most people who embark on this construction adventure agree that it’s fun and incredibly rewarding. It can be an activity shared by the family that really turns the construction of a house into the realization of your home.
See 114 more comments