Realtor® of the Week
Chantal Christin
Affiliated Real Estate Agent
groupe sutton - synergie inc.
Terrebonne, Quebec
A House of Straw
A house made of straw makes most people think of the unfortunate porcine homeowner in the children’s story, The Three Little Pigs, who had his house destroyed by a windy wolf. While that fictitious pig lived in straw home of dubious quality, in reality, people in many countries reside in well-built straw houses, and have done so for more than a century in North America.
The history of straw homes began in the 1800’s in the sandhills region of Nebraska. While settlers to the area found very few trees to use for lumber, there was plenty of land on which to grow crops like wheat, oats, and barley. Once the crops were harvested, the remaining stalks were cut down, gathered, compressed, and formed into blocks. The settlers used the straw bales to build shelters for themselves and their animals that were durable and provided protection from the elements. They found that straw bale buildings retained heat very well in the winter and stayed cool during the summer, two of the main reasons why people today build straw bale homes.
In the 20th century, straw bale construction declined because other building materials became readily available. It was rediscovered a generation ago in the U.S. southwest, where the hot climate and concern for the environment caused people to search for a building material that had excellent thermal insulation and was strong, durable, and “green”. The solution was straw bale construction, and during the 1980’s and ‘90’s, hundreds of straw bale homes and other structures were built.
How energy efficient are straw bale houses? According to the Canada Mortgage and Housing Corporation, they are 25 to 40 percent more energy efficient than homes built using lumber, bricks, fibreglass insulation, etc. The greater energy efficiency means significantly lower heating costs, and many straw bale homeowners have found that they do not require air conditioning. Other advantages of using straw bales in home construction are wide availability, low cost, excellent sound insulation, low environmental impact, durability, and convenient size for handling.
A straw bale house looks like a home made from more conventional materials. Both types have concrete foundations, a roof, doors and windows, electrical wiring, lighting, etc. As well, both types last for decades with proper maintenance - there are straw bale houses in very good condition that are more than a century old. Many people are surprised to learn that straw bale houses are not limited to a single-story; 2- and 3-storey homes exist in various countries.
One of the noticeable differences between straw bale houses and other types of homes is the greater thickness of the walls in the former. The common bale width is 18 inches, with a thermal insulation rating (R-value) of forty-eight. Fibreglass batting or foam insulation used in exterior house walls have an R-value of between 12 and 20. R-value is a measure of how well a material resists heat passing through it. The higher the R-value, the more effective the insulation is in keeping the home warm in winter and cool in summer.
The most common type of straw bale wall used in home construction is “post-and-beam”. A wood framework (steel or concrete is sometimes used) is erected, and straw bales placed between the vertical supports as insulation. In some jurisdictions, straw bales alone are allowed for load-bearing walls. A top-plate is laid above the bale wall and secured to the foundation by metal rods and/or strapping. The roof is then attached to the top plate. In either type of wall, the bales are stacked and pinned with rebar, wood, or bamboo stakes. For added strength, chicken wire is often wrapped inside and out, and sewn tight to the bales. An earth plaster or cement stucco is applied as a finish (bales will also hold plaster without wire mesh). Natural, non-toxic paints are recommended for surfaces.
Indoor air quality is very good in straw bale homes because the bales and natural plaster allow the walls to “breathe”, allowing a gradual transfer of air through the wall. Straw bale walls block out so much exterior noise that one Nebraska pioneer family was found playing cards in their kitchen, oblivious to the roar of the tornado that had gone through the area!
What about the potential effects of fire, insects, and moisture on straw bale homes? Individual stalks of straw burn, but when compressed into bales, they actually resist combustion. Plastered straw bale walls have easily passed two-hour fire laboratory tests, a building code requirement. Anecdotal evidence indicates no problem with bugs. Concerning moisture, with a proper foundation, roof, and finish plaster, straw bale walls resist dampness very well, as century-old homes in the U.S. prove. However, in areas with a high amount of annual rainfall like coastal British Columbia, other types of materials for exterior home walls will require less monitoring and maintenance than those made with straw bales.
As with other types of houses, straw bale homes must conform to local building codes. Contact the engineering department of your municipal government for more information. Several jurisdictions in North America have building codes for straw bale houses. Also, find out from your insurer if you can obtain home insurance for a straw bale residence; a number of large insurance companies provide coverage.
There are many sources of information about straw bale homes including books, videos, workshops and the Internet. The Last Straw’s website (http://www.strawhomes.com) has links to Canadian architects and contractors who specialize in straw bale home construction. If you are interested in contacting a straw bale home owner/builder, try Glen Hunter via his website (http://www.glenhunter.ca). Glen graciously provided information for this article. As he will attest, building and living in a house of straw can be a great experience!
The history of straw homes began in the 1800’s in the sandhills region of Nebraska. While settlers to the area found very few trees to use for lumber, there was plenty of land on which to grow crops like wheat, oats, and barley. Once the crops were harvested, the remaining stalks were cut down, gathered, compressed, and formed into blocks. The settlers used the straw bales to build shelters for themselves and their animals that were durable and provided protection from the elements. They found that straw bale buildings retained heat very well in the winter and stayed cool during the summer, two of the main reasons why people today build straw bale homes.
In the 20th century, straw bale construction declined because other building materials became readily available. It was rediscovered a generation ago in the U.S. southwest, where the hot climate and concern for the environment caused people to search for a building material that had excellent thermal insulation and was strong, durable, and “green”. The solution was straw bale construction, and during the 1980’s and ‘90’s, hundreds of straw bale homes and other structures were built.
How energy efficient are straw bale houses? According to the Canada Mortgage and Housing Corporation, they are 25 to 40 percent more energy efficient than homes built using lumber, bricks, fibreglass insulation, etc. The greater energy efficiency means significantly lower heating costs, and many straw bale homeowners have found that they do not require air conditioning. Other advantages of using straw bales in home construction are wide availability, low cost, excellent sound insulation, low environmental impact, durability, and convenient size for handling.
A straw bale house looks like a home made from more conventional materials. Both types have concrete foundations, a roof, doors and windows, electrical wiring, lighting, etc. As well, both types last for decades with proper maintenance - there are straw bale houses in very good condition that are more than a century old. Many people are surprised to learn that straw bale houses are not limited to a single-story; 2- and 3-storey homes exist in various countries.
One of the noticeable differences between straw bale houses and other types of homes is the greater thickness of the walls in the former. The common bale width is 18 inches, with a thermal insulation rating (R-value) of forty-eight. Fibreglass batting or foam insulation used in exterior house walls have an R-value of between 12 and 20. R-value is a measure of how well a material resists heat passing through it. The higher the R-value, the more effective the insulation is in keeping the home warm in winter and cool in summer.
The most common type of straw bale wall used in home construction is “post-and-beam”. A wood framework (steel or concrete is sometimes used) is erected, and straw bales placed between the vertical supports as insulation. In some jurisdictions, straw bales alone are allowed for load-bearing walls. A top-plate is laid above the bale wall and secured to the foundation by metal rods and/or strapping. The roof is then attached to the top plate. In either type of wall, the bales are stacked and pinned with rebar, wood, or bamboo stakes. For added strength, chicken wire is often wrapped inside and out, and sewn tight to the bales. An earth plaster or cement stucco is applied as a finish (bales will also hold plaster without wire mesh). Natural, non-toxic paints are recommended for surfaces.
Indoor air quality is very good in straw bale homes because the bales and natural plaster allow the walls to “breathe”, allowing a gradual transfer of air through the wall. Straw bale walls block out so much exterior noise that one Nebraska pioneer family was found playing cards in their kitchen, oblivious to the roar of the tornado that had gone through the area!
What about the potential effects of fire, insects, and moisture on straw bale homes? Individual stalks of straw burn, but when compressed into bales, they actually resist combustion. Plastered straw bale walls have easily passed two-hour fire laboratory tests, a building code requirement. Anecdotal evidence indicates no problem with bugs. Concerning moisture, with a proper foundation, roof, and finish plaster, straw bale walls resist dampness very well, as century-old homes in the U.S. prove. However, in areas with a high amount of annual rainfall like coastal British Columbia, other types of materials for exterior home walls will require less monitoring and maintenance than those made with straw bales.
As with other types of houses, straw bale homes must conform to local building codes. Contact the engineering department of your municipal government for more information. Several jurisdictions in North America have building codes for straw bale houses. Also, find out from your insurer if you can obtain home insurance for a straw bale residence; a number of large insurance companies provide coverage.
There are many sources of information about straw bale homes including books, videos, workshops and the Internet. The Last Straw’s website (http://www.strawhomes.com) has links to Canadian architects and contractors who specialize in straw bale home construction. If you are interested in contacting a straw bale home owner/builder, try Glen Hunter via his website (http://www.glenhunter.ca). Glen graciously provided information for this article. As he will attest, building and living in a house of straw can be a great experience!