Although large population trends, such as the skyrocketing number of seniors in the United States, grab a lot of attention, the nation is also on the cusp of a smaller demographic boom. Between 2000 and 2008 the rate of autism diagnoses increased dramatically, up from 1 in 150 children to 1 in 88. Over the next decade, about 500,000 children with autism will reach adulthood, with no clear path to managing their lives on their own. “There's not a solution for where they're going to live long-term when their families are no longer able to take care of them,” says Marsha Maytum, principal of Leddy Maytum Stacy Architects (LMS).

In 2009, a group of parents and autism professionals began working on this problem. They formed a nonprofit, Sweetwater Spectrum, and bought a 2.8-acre urban infill site just off the old town square in Sonoma, California. The board of directors brought on LMS to conceive a new housing model grounded in the latest research. In addition to specific requirements—such as a legible, repetition-based site layout and interiors that reduce sensory stimulation—the board and the design team started with the premise that adults with autism should have the opportunity for self-determination.