Straw bale construction, a re-emerging non-toxic building technique, uses bundles of tightly compressed straw as structural insulation for homes and commercial buildings. Straw bales are derived from dried, leftover stalks or husks of harvested grains, such as barley, rice, wheat, or rye. Straw is hollow, slow to decay, and a durable agricultural by-product often used for animal bedding and landscaping. In the late 1800s, straw bale homes first became popular in farming regions with limited timber supplies, such as Nebraska. Since then, legitimate use has expanded with the establishment of building codes for straw bale in the 1990s.
Today, contractors or homeowners can buy compressed, rectangular blocks of straw from farmers. The Consumer Energy Center estimates that the United States generates 200 million tons of straw waste annually. Rather than wasting this straw, we should use it for building. The two most common forms of design are the non-load bearing infill and the load-bearing straw bale constructions. Infill designs place straw bales in between a structural wood frame while load-bearing construction interlocks bales to form free-standing walls. Straw bales bond well with the environmentally-friendly stucco or plaster used to finish and seal interior and exterior walls. “Unlike most manufactured building materials…a straw bale home blends energy efficiency and aesthetics with a healthy indoor environment,” says Catherine Wanek, author of The New Strawbale Home.
Straw bale construction reduces air pollution and CO2 emissions by circumventing the burning of straw waste. Bale thickness, ranging from 14 to 24-inches, offers a high degree of insulation, increasing energy efficiency. This method is sustainable because straw is plentiful and easily replenished by industrial agriculture. Contrary to popular belief, straw bale structures are highly fire resistant. Straw compression limits oxygen availability and fuel combustion. If walls are kept moisture-free, buildings can last indefinitely. Straw bale homes built 200 years ago are still standing.
Even with their long life span, there are a few concerns to consider when building with straw. Wanek says total costs are more or less equal to conventional construction methods. The biggest constraints tend to be the extensive time and energy required for proper construction and the risk of moisture exposure, according to Building Green authors Clark Snell and Tim Callahan. Where straw bale constructions are concerned, the metaphorical big bad wolf tends to be water. Bales must have 20% or lower moisture readings or they become susceptible to fungus and mold. So could a straw bale building be viable in the humid, temperate climates of New York State?
If designed properly, a straw bale building is feasible in any environment. A local example of this is the straw bale home of farmers, Amy Yahna and Brian Musician of Lebanon, NY. The couple built their home in two years using 20-inch straw bales with lime and earthen plaster. Local natural contractors specifically designed the home for continuous moisture. “It’s solid. It’s like a brick wall,” Yahna reported to the Post Standard. Maybe someone should have told the three little pigs about proper straw bale construction; they could have saved some hassle.