Accessory Dwelling Units

California Department of Housing & Community Development
ADUs have been known by many names: granny flats, in-law units, backyard cottages, secondary units and more. HCD is the state’s leader on local ADU ordinances, which — while optional — have grown exponentially in number as more cities, counties, and homeowners become interested in ADUs as one solution to increasing the supply of affordable housing.

Download HCD's Accessory Dwelling Unit Handbook (January 2025)