Straw Bale & Solar Housing Article

STRAWBALE & SOLAR FOR A SUSTAINABLE EARTH

AN IDEAL MARRIAGE
 

 

THE PROBLEM 
 

     In the 1990’s the international community set goals for saving the world as we know it from destruction by “greenhouse” gases and global warming.  (Kyoto and other agreements.)  These goals are not being met.  The destruction of the vast tropical and subarctic forests through timbering and drought-enhanced fires continues.  Antarctica, glaciers worldwide, and the polar ice cap are melting.  Petroleum and other non-renewable carbon-based fuels are being used up.  They become ever more expensive, hurting the poorer countries catastrophically and leading to conflict and war in many parts of the world. 

     Our own desires for comfort and convenience are reflected throughout the world.  One point three billion Chinese want to be warm in winter and cool in summer.  A billion Indians desperately need to be cool in summer as global warming makes sustained temperatures above 100 degrees f (38 degrees C)  a frequent occurrence.  Even in the US, sustained high summer temperatures have killed hundreds of people annually in recent years.

     Solar technology, both active and passive, can stop the burning of much fuel and save us from the greenhouse gases and acid rain thereby produced.  This information has been fairly well publicized.  Since manufacturers (at least in developed countries) can potentially make money by promoting active solar, this technology will gain ever-increasing exposure.  The same is true for wind power as can be seen especially in Europe.  British Petroleum (BP) has already “seen the light” and is actively promoting their Solar Division’s products.  Unfortunately, American oil companies are not so far-sighted.  We should be conserving as much oil and coal as possible for their useful chemical properties.  What will we use for industrial chemicals a hundred years from now if we empty the Alaskan National Wildlife Reserve’s petroleum deposits now, instead of when we truly have an emergency?  We must also reduce our dependence on foreign oil and the potential political instability thereby created.

     What has not received so much attention is the amazing potential of straw bale construction.  Strawbale (SB) homes, schools and other buildings can range from the primitive to the sophisticated, but their production remains in the hands of home owners (often the actual builders), farmers (the bale producers), and architects (the designers of higher-end SB).  Since major corporations have fewer incentives to become involved it is up to us, the people, to spread the word and knowledge of this world-saving approach to home building.

   

A SOLUTION 
 

     History – First let us look at what strawbale construction is, and then at what could be saved.  Modern SB construction originated about 100 years ago in the Sand Hills area of Nebraska which lacked timber, but had quality hay.  The recent invention of horse or steam powered baling machines made possible good compressed hay or straw for wire or string tied rectangular blocks called bales  (Modern bales are typically 2 or 3 string tied—polypropylene twine is best—and roughly 36” x 18”  x 14”, or 46” x 23” x 16”.)  Nebraska settlers desperate for housing before severe winters set in, would use the bales like giant bricks for temporary walls, often resting pole and sod roofs directly on the bales.  When they discovered how comfortable these homes were in the extremes of winter and summer, they were often plastered and adapted as permanent dwellings.  This “load-bearing” type, resting the roof supports directly on the bales was the norm for decades.

     Load-bearing construction is good for one-story buildings, but in 1938 a mansion using 2,200 wheat-straw bales was built in Huntsville, Alabama.  It is now the Burritt Museum.  This “non-loadbearing” type of building used the infill bale technique in which a frame (often barn style post and beam) and roof are built first and the bales set in the open spaces.  Two or more stories are possible with this second major type of bale structure, but technical help with design may be needed.

     There are also hybrid and other methods for using bales in larger structures.  Bales can be used to retrofit commercial metal or pole-building kit structures, such as farm sheds, warehouses and workshops.  Other existing buildings can be wrapped with bales, the roofs extended and doors and windows modified.

    

     Benefits of Change – Straw is the waste stems from harvested wheat, rice, rye, oats, barley, etc.  Unlike hay which is used for animal feed and has rodent attracting seeds, straw is a waste product.  It is hard to get rid of except by burning causing greenhouse gases (carbon monoxide and nitrous oxide), and health-harming air pollution.  Rice straw with its high silica content may be the worst.  Rotting straw releases the greenhouse gas methane.  Some straw is useful for soil conditioning, erosion control and animal bedding.  Matts Myhrman says that if all US post-harvest straw were bales, 5 million 2,000 sq. ft. homes could be built annually  (Annual conventional housing starts are about 1 million.)

     In 1991 Calif. Agr. Mag., vol. 45, no. 4, compared annual carbon monoxide production in that state by straw burning and power plants as follows: 
 

          Source of CO                  Tons Burned                    Tons CO Produced 
 

          Power plants                                                                     25,000

          Rice  straw                        1,000,000                                56,000

          Wheat straw                           97,000                                 5,000 
 

As you can see, that year straw burning produced more than twice as much CO as did power plants.  A state crackdown on burning may be helping, but there is still the disposal problem.  Ken Williams at a SB building seminar reported that California produces enough straw per year to build 45,000 homes.

     It boggles the mind to imagine how many SB homes could be built of rice straw in China and Japan, or wheat and rye straw in Russia, the central Asian steppes and parts of Pakistan and north India.  Simple adobe stucco can be hand applied inside and out to finish the kind of small homes and farm buildings that peasants and villagers might build.

     Fiberglass insulation ratings for a standard wall of 2” x 4” studs is R-11, and for 2” x 6” walls it is R-19.  Walls of standard bales have about an R-50 insulation rating.  If a sandwich roof with straw infill is used, the R rating for the dwelling can be much higher—perhaps R-80 or R-90. Thus, heating and cooling costs are lowered greatly.  In less developed countries forest destruction for both timber and firewood would be vastly reduced.  In densely populated areas health destroying air pollution would be greatly lessened. 
 

     Other benefits include: 
 

1. The light weight of bales, their flexibility and ease of reinforcement with bamboo, metal, or wood pins provides excellent earthquake resistance and lifesaving potential compared with the heavy stone, adobe, or earth blocks used in 80% of the world's homes.
2. People, including women and children, are empowered and given pride by building something lasting that involves all their participation.
3. In overpopulated river valleys far less scarce agricultural soil is needed for coating SB structures than for making solid adobe or earthen blocks.
4. The dense walls block noise pollution, promoting tranquility and peace, especially beneficial in crowded communities, multi-unit buildings and windy lands.
5. Use of plaster/stucco construction permits “painting” with incorporated dry natural pigments or whitewash, reducing use of toxic paints and solvents.
6. Fast growing bamboo, common in many heavily populated countries can be used with SB for roofing and other structural purposes.
7. Fewer or no toxic components results in a healthy house that “breathes”.
8. Strawbale walls are bullet proof.

 
 

CONCLUSION 
 

     Each of the above-mentioned technologies—solar, wind power, and strawbale—if widely used—has the potential to significantly reduce greenhouse gas emissions.  However, if solar or wind power were combined with SB structures, the savings could be doubled, tripled or quadrupled.

     By way of example, Spain has a goal of producing 20% of national energy using wind power within 10 years.  If Spain were to combine this power with significant use of SB construction, perhaps wind power could provide 30 to 50% of national energy needs.

      After Hurricanes Katrina and Rita, Americans are finally becoming aware of how interconnected the world is where energy is concerned.  We can see how energy use in China and India with a combined population roughly eight times our own is bound to greatly increase our energy costs, even without intervening disasters. If just these two countries could be helped to introduce SB housing on a massive scale it would greatly improve the future world-wide energy picture.

As pointed out earlier, there is much less incentive for large corporations to be interested in promoting SB technology as compared to solar and wind energy products.  Therefore, if the major energy saving potential of SB construction is to be realized, it is important for governments overseas, nationally, statewide and locally to become involved in promotion.  In the long run, government funding for demonstration projects, technical education and training in the US and overseas would be far cheaper than the high cost of energy. The current disaster areas in the American Gulf Coast and in Pakistan might be good places for experimental or demonstration projects using this technology.

     These costs will impact us in ways we are only beginning to see.  They will affect the economy leading either to higher prices or less economic activity, and potential loss of tax revenues.  Government costs to assist the poor with their energy needs promises to be very high.  After this winter, we will have a clearer picture of just how high. 
 
 

SOURCES 
 

MacDonald, S.O. & Myhrman, M.:  Build it with Bales, Out on Bale, Tucson, AZ, 1995. 
 

Steen, A.S., Steen, B. & Bainbridge, D. (with D. Eisenberg):  The Straw Bale House, Chelsea Green Publishing Co., White River Junction, VT, 1994. 
 

Williams, K.:  Personal communication
 
 
 
 

© Lee Aikin, Oct. 2005. Updated June 2006.