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Straw Bale Structures

Unstuccoed straw bale walls and roof framing in Urbana, Illinois home

Why straw bale construction?

  • Energy Efficiency: The natural insulating properties of straw offer a minimum R-35 value in the walls. Once stucco and plaster are applied to each side, the value is estimated to be as high as R-50.
  • Fire Resistance: Because there are no “hollow” walls in straw bale buildings, they are very resistant to fire.
  • Insect Resistance: While properly finished walls still allow vapor transference, the 2-inch “skin” of stucco and plaster on each side prevents access by insects and other pests.
  • Earthquake Resistance: The shock-absorbing quality of straw, combined with the width-to-height ratio of the walls, allows straw bale structures to perform better than frame construction during earthquakes or tremors.
  • Wind Resistance: When a bale wall is plastered and stuccoed, it has extremely high lateral and compressive load capabilities. These walls have tested at 100 pounds per lineal foot for lateral strength and 4,000 pounds per square foot for compressive strength. Current code requirements in our area specify only 20 pounds per lineal foot for lateral strength.
  • Cost Effectiveness: For all of its energy and safety advantages, straw bale construction typically costs only about 10% more than standard methods.