How Many Bales Does It Take to Build a Home?

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.