Question: How are straw-bale homes built?
Answer: Because of seismic concerns, most builders in California use straw as insulation and not as a load-bearing material. Builders typically fill the walls of a post-and-beam framework with straw bales, skewer the bales with reinforcing bar to stabilize them and then cover the bales with chicken wire and clay, stucco or plaster.
Q: Are there other ways to build with straw?
A: In some homes, there is no load-bearing framework and straw-bale walls are used to support the roof.
Q: How big are straw bales?
A: Builders in California use three-string bales, which are 2 feet wide, 15 inches high and 4 feet long.
Q: How much do they weigh?
A: Sixty to 80 pounds each.
Q: How much do they cost?
A: About $3 each, including the delivery fee.
Q: How many bales are in the average home?
A: Three hundred to 400.
Q: What is straw?
A: Straw comes from the stems of cut and dried grasses and grains, such as rice, wheat, barley, rye and oats. Straw is left over after the grain is removed. It’s a waste material and should not be confused with hay, which is nutritious.
Q: Where does straw come from?
A: California is the nation’s second-largest rice straw producer.
Q: What do farmers do with leftover straw?
A: Burn it. But farmers here have been ordered by the state Legislature to stop burning up to 90% of their rice straw in the next few years.
Q: How much straw is available to build homes?
A: The U.S. Department of Agriculture estimates farmers harvest enough straw annually to build about 4 million 2,000-square-foot homes.
