Burdensome regulations stymie backyard cottage production, UC Berkeley study finds

Building new backyard cottages - called accessory dwelling units - is a critical part of fixing California's housing crisis, says Karen Chapple, chair of UC Berkeley's city and regional planning program. (Photo courtesy of UC Berkeley. Despite numerous California state legislative wins in support of Accessory Dwelling Units (ADUs) in the last three years, local regulations still limit their production, UC Berkeley researchers have found. UC Berkeley's Center for Community Innovation graded local ADU ordinances throughout the state on a scale of A-F on their friendliness to ADU construction. Researchers reviewed over 200 ordinances based on 16 equally weighted criteria assessing their consistency with state law and user-friendliness for homeowners. Cities received extra credit for relaxed parking requirements for ADUs and maximum size requirements for attached and detached ADUs. "Making it easy to build ADUs is a critical piece of the comprehensive approach to housing needed to solve California's affordability crisis," said Karen Chapple, faculty director of the center and professor and chair of the Department of City and Regional Planning.