ADUs are a fixture throughout Southern California. However, these little structures come with a big list of rules and regulations. Governor Newsom has signed a slate of new bills that reshape the ADU landscape, including who can build them and where. Read this article for a summary of the key changes taking effect as of January 1st, 2026.
Coastal Permits
ADUs built in certain coastal zones require a special coastal development. These permits are subject to appeals and longer timelines than regular permits for ADUs. However, starting in 2025, these permits will be required to be approved or denied within 60 days, dramatically shortening the current wait times which could stretch out to months or longer.
Another change related to occupancy rules after a natural disaster such as a wildfire. In disaster-affected areas, detached ADUs are able to obtain a certificate of occupancy before the main residence after a disaster if certain conditions are met.
JADU Owner Occupancy
Junior Accessory Dwelling Units, commonly known as JADUs, are smaller structures within a larger home. They are often converted bedrooms, garages or other portions of the main property. Under the new 2026 rules, the primary home no longer needs to be owner-occupied.
It’s important to note that the elimination of the owner-occupancy rule only pertains to JADUs with their own bathrooms. If the JADU shares a bathroom with the main house, then owner-occupancy is still required. Additionally, the law stipulates that JADUs are prohibited from being used as short-term rentals for under 30 days.
ADU Sizes, Fees, and Permits
SB 543 specifies size limits for ADUs and JADUs refer to inferior livable spaces. Furthermore, it clarifies that JADUs are defined as interior livable spaces under 500 square feet. Under this law, ADUs and JADUs will be excluded from certain fees, including development impact fees which are typically levied upon new development projects to help fund public infrastructure.
The permitting process for ADUs is also changing under SB 543. Starting in 2026, local Los Angeles agencies are required to provide a completeness determination within 15 business days for all ADU applications. If the application is found incomplete, the agency must provide a written list of items to fix so applicants can cure the errors and resubmit.
Tracking the Evolving ADU Landscape
The basic principle of the ADU stays the same: a small, safe dwelling attached to your property. However, the rules keep changing as California balances its housing needs with its goals for sustainability and economic growth. As the new laws come into play, Creative Innovation Developers stays on top of the changes to ensure your new construction ADU is fully compliant with all ordinances. Reach out to us today to get started on your ADU project.
