Sonora grows over a million acres in wheat a year, and typically instead of baling it, the fields are burned to dispose of the remaining stalks-straw. Inspiration for alternatives. Save the Children's first straw bale structure. First straw bale house in Cd. Obregon. Straw filled in boxes adds insulation to the standard heavy-cement roofs. Save the Children started a project of building a dozen straw bale houses in Aves de Castillo. Unfortunately, the peso devalued overnight and the cost of cement doubled. Many of the houses started were never finished. Low income housing - 400 sq ft. block rooms for $20,000 US dollars. Low income housing. Like ants, children are a great labor force. Sand bags filled with gravel and dirt keep the bales off the ground. Clay slip is mixed with lots of straw to create a thick base coat that adheres directly to the bales. Athena and Juanita apply mud plaster. Oso (4 yrs) helps Athena level gravel for an earthen floor. As an experiment, external bamboo pins were run diagonally for increased strength. Bill Steen Teodoro Lopez A straw-clay mix was then put on top of the reeds and plastered with lime.