ADU Application Deadlines in California: SB 543

Since January 1, 2026, Senate Bill 543 (Chapter 520, Statutes of 2025) sets the clock on accessory dwelling unit and junior accessory dwelling unit applications in California. It amended the ADU chapter of the Government Code (sections 66310 and following). It does not change the general Permit Streamlining Act; it applies to ADU and JADU applications.

The agency has 15 business days from submittal to determine in writing whether the application is complete and, if it is not, to list what is missing. If the agency does not act within 15 business days, the application is deemed complete.

On resubmittal, the review is limited to the items the agency listed. New completeness items cannot be added later.

The agency has 60 days from a complete application to approve or deny it; that rule predates SB 543. If it does neither, the application is deemed approved.

An applicant whose application is found incomplete may appeal in writing, and the agency owes a final written determination within 60 business days.

The applicant may ask to pause the clock. An ADU submitted together with a new single-family home may wait for the decision on the home.

Date-stamp the submittal and calendar the fifteenth business day and the sixtieth day. When a date passes with no written determination, say so to the planner in writing, with the section. A correction that raises a new completeness item after the fifteenth business day, or a code item the city’s own ordinance does not support, is the thing to answer in writing rather than redraw.

Source: Senate Bill 543 (2025), Chapter 520, effective January 1, 2026, as read in October 2026. Confirm the current text before relying on it.