Among the green building solutions available to homeowners today is the straw-bale house. Many buyers shy aware from this economical solution based on misconceptions and misunderstandings. Here are a few of the common arguments for and against straw-bale construction:
Myth: Straw-bale homes catch fire more easily than stick built homes.
Fact: While straw in a field is highly combustible, the straw bales are tightly compacted making fire less likely. Since straw bales contain very little air they will not easily combust. Bales covered with plaster or stucco are fire-resistant and provide even greater insulation. Other siding materials such as wood or aluminum are less desirable since any gaps allow more air along the straw-bale surface and increase the risk of fire.
Myth: Rodents and wood-eating insects are a risk.
Fact: Hay provides food value to animals and insects, straw does not. Straw is used to build houses because it does not attract rodents, termites or other insects. Actually, a conventional, stick-built house is more likely to suffer a termite infestation than a straw-bale house.
As with any home, with proper maintenance and repair of any holes your straw-bale home will provide many years of comfort and safety.
Myth: Straw-bale homes trap humidity.
Fact: Because the straw bales are porous, they "breathe" allowing humidity to circulate out of the walls. Because of this, moisture content hovers at less than 20%, similar to most other types of homes in the same area. In humid environments, builders recommend using lime-based plasters.
Myth: Straw-bale homes rot in areas of high rainfall.
Fact: Rainfall is not a problem in properly constructed homes. Waterproof barriers and properly engineered ground and roof drainage systems will mitigate any risk of rot.
Myth: Straw is organic so it will decompose.
Fact: Yes, straw is an organic material but in order for it to decompose both air and water are required. If your home is properly built to reduce air pockets and humidity, the straw will not decompose. Rice straw is a particularly decay-resistant building material.
Myth: Straw stinks.
Fact: Since straw is a natural material it will not out-gas chemicals or "cut" you like fiberglass insulation. However, straw will provide a greater insulation value than fiberglass and have zero VOC meaning it is greener for you and for the environment.
Myth: Bales are bulky and limit my design creativity.
Fact: Bales provide interesting architectural nooks and ledges. Spend some time perusing the many creative designs available and you will easily see your creative options are unlimited.
Myth: Stick-built homes are just as "green" as straw-bale homes.
Fact: Straw is a sustainable, inexpensive resource. According the California Energy Commission, over 200 million tons of straw is generated in the U.S. every year. Rather than burning straw and producing tons of environmentally destructive carbon dioxide, straw can be converted into a home that lasts for hundreds of years. It takes less energy to heat and cool a straw home than a stick-built home. The R-value of straw-bale wall is between R-32 and R-42, two to three times better than the walls of most conventional homes. The bales also provide a highly effective sound barrier.
Builders and property owners interested in reducing their carbon footprint, using renewable and sustainable building materials, and reducing costs to heat and cool their structures will find straw-bale structures to be a worthy option for consideration.
Photo credit: Nancy Wicks/Round Mountain Institute. This house is for sale!