What are my rights under CA State ADU Law?
Building a New ADU
Parking requirements have been reduced or waived entirely, homeowners are allowed to convert existing buildings and multifamily property owners are allowed to convert existing unused space.
ADUs are allowed in all residential and multifamily zones with limited exceptions for public safety, traffic, and water. Homeowners Associations cannot ban ADUs and multifamily properties can add detached ADUs.
State law has also created an opportunity for homeowners to bring ADUs built without permits into compliance, including allowing building officials to apply building standards that were in place during the time the ADUs were constructed and a five-year amnesty period.
Converting Existing Space into an ADU
State law now allows homeowners and multifamily property owners the right to convert many types of existing space into ADUs.
If residential uses are allowed where your property is located and it was built legally, you can convert garages, pool houses or other out-buildings to ADUs.
The structure must be located in a residential zone.
The structure must have been built legally initially.
The ADU must have a door that provides direct access to the outside. (This door can be added during construction if it is not there in the existing building.)
The existing house must be far enough away from the property line to not be a fire hazard. Discuss specifics with your city.
Fees
Cities cannot charge impact fees for ADUs under 750 square feet and must charge reduced fees for larger ones. (They still can charge inspection fees, but these are usually less.) In addition, water or sewer providers are not allowed to charge a connection fee when converting existing space into an ADU.
Owner Occupancy
In the past, some cities had rules that required owners to live on a property if there was an ADU. These rules have been banned for any ADUs built between 2020 and 2025; however, this requirement still applies to JADUs. The owner may live in the JADU or in the main part of the dwelling.
About Casita Coalition
Casita Coalition is the only statewide, multi-sector organization that brings together all key players to remove policy barriers, making a big impact through small homes. Working through our Board, Advisory Committee, and Working Groups, we draw on the diversity of expertise and experience of our members to make it easier to build small homes in all neighborhoods across California. Visit www.casitacoalition.org to learn more.