Pre-Approved ADU Plans
AB 1332: Accessory dwelling units: preapproved plans


As is an annual tradition in the California legislature, elected officials passed a new law regarding Accessory Dwelling Units (ADU) in California in 2023.  In our final installment of this year’s “Guide to Changes in State Law”, we cover a significant bill that CALBO actively worked on through the legislative session to address California’s housing crisis, while maintaining local control.  AB 1332 by Assemblymember Juan Carrillo a former city planner and the new chair of the Assembly Local Government committee, requires local jurisdictions to adopt a program for the preapproval of ADUs. Before we get to the specifics, don’t forget to read our previous installments of this year’s articles for AB 548, AB 358, and AB 42.  In the next sections, we cover the specific aspects of the bill, but first, it’s story time.

AB 1332 was written with consultation from CALBO’s Legislative Team as the author’s office approached us early in the legislative session with the proposal.  Originally, the bill was going to require 6 permit-ready ADU plans established by the local government, but with CALBO’s assistance and the author’s willingness to work with us, the bill pivoted to focusing on a preapproval program for ADUs. We sincerely appreciate the efforts of Assemblymember Carrillo’s team to work through the details with us in the bill.  As with any policy in Sacramento, some compromises were reached but in all this bill should provide a great benefit to our members and allow local governments to help streamline their efforts in California. Below are the specifics of the bill.

AB 1332 requires all local agencies by January 1, 2025, to develop a program for the preapproval of accessory dwelling unit plans.  CALBO’s understanding is this can mean either an online database of plans that the jurisdictions have preapproved or a PDF on your local website that provides examples of floor plans that your jurisdiction has given the green light to.  The bill specifies that the local jurisdiction decides what kind of ADU floor plans are permitted for preapproval. In other words, an architect or nonprofit organization may come to your jurisdiction and request their floor plans to be considered for preapproval, and building departments can decide whether to accept the plans or not in the program.

According to the new law, the preapproval program must comply with the following requirements: local agencies must accept accessory dwelling unit plan submissions for preapproval, may not restrict who is submitting plans to the program, and the local agency must approve or deny an application for preapproval based on public health and safety.  Additionally, local jurisdictions must post the plans approved for the program online on the agency’s website and include the contact information of the author/designer for the preapproved ADU plan. Finally, local building departments are allowed to charge the same permitting fees that a local agency would charge for an applicant seeking approval for the same-sized ADU when reviewing the permits for the ADU plans in the preapproval program. This was an important aspect of CALBO’s work on this bill.

A second requirement that is important to know with the bill is that the bill requires a local agency to approve or deny an application for a detached ADU within 30 days of receiving the application if the applicant uses either a preapproved ADU plan (as determined by the local agency) or is identical to a plan approved by the local agency during the current triennial code cycle.  Although the latter part of the bill is concerning, it is important to recognize that locally you may have to prioritize these applications as you still can deny an application for public health and safety concerns.

When establishing your preapproval program by January 2025, it is important to understand that the bill allows your agency to use either plans that have been developed and deemed qualified for preapproval by your agency or you can use plans that have been preapproved by other agencies in the state to comply with the bill.  For example, if you are a smaller jurisdiction, you can use plans that have been preapproved in larger cities such as Los Angeles or San Jose to comply with the bill if it fits your community’s needs.  CALBO has established some examples of preapproved programs already established in California which can be found here.

CALBO is optimistic the new law will provide a more efficient approach to ADU development in California while streamlining local building departments’ jobs on the ground for this kind of housing.  Although unfunded mandates, a shot clock on permits, and new requirements for local enforcement agencies are nonstarters for CALBO’s advocacy efforts, this bill provides a balance of prudent, feasible policy, while granting local government control of what is best for their respective communities. 

If your jurisdiction would like to be included in the document for an approved preapproval program, please contact and let me know that your jurisdiction’s plan would like to be added online.  Should you have any questions or concerns, please feel free to reach out.