In Ciudad Obregon, Mexico, low-income families live in slapdash houses improvised out of cardboard, scrap wood, discarded sheet metal, and corrugated asphalt shingles. These desert homes are unbearably hot in summer and cold in winter. In 1994, Save the Children, a foundation dedicated to improving children’s lives, recognized the need for comfortable, inexpensive housing and asked for help from the nonprofit Canelo Project, created by Arizona-based builders, authors, and teachers Athena and Bill Steen.

The Steens, authors of The Straw Bale House (Chelsea Green, 1994) and The Beauty of Straw Bale Homes (Chelsea Green, 2001), traveled to Mexico and discovered that Ciudad Obregon is in the center of the largest wheat-producing area in Mexico. Straw is a ubiquitous waste product from wheat fields, and it can be had for free. The Steens worked with residents in one of the poorest neighborhoods to build several small straw bale houses. They used local clay instead of cement and brick. A bamboo-like reed called carrizo replaced rebar. The houses cost an average of $2 per square foot.

The residents were enthusiastic about the comfort and cost of their new homes—but not about the aesthetics. They associated clay and carrizo with poverty and preferred the straight walls and sharp right angles of concrete and brick construction. Then, in 1997, the peso was devalued dramatically and caused the price of concrete to double. Around the same time, a hurricane demolished many of the slapdash houses, but the straw bale structures weathered the storm. Suddenly, there was renewed interest in the Canelo Project’s techniques. The Steens returned to Mexico and worked with the local people to develop a straw/clay block that created more angular walls and took advantage of the local workers’ block-laying skills.