The startup, called Oby (“our backyard”), a spinoff of a company called CoEverything, is taking a new approach to affordable housing: It finds homeowners who are willing to share their backyards, then builds a tiny backyard house, which it rent at rates well below market rate. By making an agreement that lasts even when the main house on the property is later sold, the business model is designed to help create a long-term solution to the area’s housing crisis. “With our company, we’re always looking at what the alternative models are that we can utilize to help build more affordable, accessible, sustainable housing,” says Declan Keefe, cofounder of CoEverything, which focuses on how to bring better practices to architecture and development. Backyard cottages are already relatively common in California. But they usually rent at market rate—something that’s out of reach for someone working as a barista, or, say, an elementary school teacher.