California Appeals Court Says Homeowners Can Challenge Delays in ADU Permits

A California appeals court has strengthened homeowners’ ability to challenge lengthy delays in accessory dwelling unit (ADU) permitting, ruling that state law’s requirements for timely, ministerial approval are intended to protect permit applicants—not just advance the state’s broader housing goals.

In an Oct. 23, 2026, published decision in Shi v. City of Palos Verdes Estates, the California Second District Court of Appeal unanimously reversed a lower court ruling in favor of the city. The decision allows homeowner Wei Shi’s claim over a multiyear permitting delay to proceed. It does not, however, establish that every delayed application automatically entitles a homeowner to damages.

What the Court Decided

Shi applied in 2020 for permission to build an ADU on his property in Palos Verdes Estates. According to his lawsuit, the city required additional reviews and approvals that were inconsistent with state law, delaying the permit until 2023.

Shi alleged that the delay caused financial harm, including higher construction costs, interest expenses, professional fees and lost use of the property. He estimated that his damages exceeded $1 million.

The trial court had ruled that California’s ADU laws were intended primarily to increase the state’s housing supply, rather than protect individual homeowners from financial losses caused by permitting delays.

The appeals court disagreed. Justice Nicholas Daum wrote the opinion, joined by Presiding Justice Audrey B. Zukin and Justice Maurice Sanchez. The court concluded that homeowners seeking ADU permits are direct beneficiaries of the state’s requirement for ministerial approval.

The judges ruled that Shi had adequately stated a claim under California’s Government Claims Act, which can make a public entity liable for harm caused by its failure to carry out a mandatory legal duty. The court reversed the lower court’s judgment, allowing the case to continue; it did not decide the final amount of any damages or establish that the city is liable for every loss Shi alleged.

What Ministerial ADU Approval Means

Ministerial approval generally means that officials evaluate an application against established, objective requirements rather than making a discretionary policy decision or holding a public hearing on whether the project should be allowed.

California law generally requires qualifying ADU applications to be reviewed under this process. Under Government Code Section 66317, a permitting agency generally must determine whether an application is complete within 15 business days of receipt and approve or deny a completed application within 60 days when an existing home is already on the lot. Exceptions can apply, including when an applicant requests a delay or when an ADU application is submitted alongside an application for a new primary dwelling.

The law does not eliminate applicable building, safety, zoning or objective design standards. Instead, it limits the ability of local agencies to use inconsistent local rules or discretionary procedures to delay or deny an otherwise qualifying application.

What the Decision Could Mean for Homeowners and Real Estate

For homeowners planning to add an ADU, the decision underscores the importance of understanding state permitting requirements and keeping records of application submissions, completeness notices, agency requests and communications with planning staff.

ADUs can provide additional living space for relatives, create potential rental income or offer flexibility for changing household needs. However, the court ruling does not guarantee faster approval in every case, nor does it guarantee that adding an ADU will increase a property’s market value. Results depend on the property, local market conditions, project costs and applicable rules.

For buyers, an existing ADU or a property with realistic potential for a secondary unit may be worth evaluating as part of a purchase decision. Buyers should verify that existing units were properly permitted and that any proposed addition is feasible under local requirements.

Sellers and investors may also want to review the permitting history of properties with ADU projects. The decision could give homeowners another legal avenue to challenge certain unlawful delays, but litigation can be costly and outcomes remain case-specific.

Potential Implications for Other Housing Laws

The ruling may also attract attention from developers and property owners working under other California housing laws that require ministerial approval. Measures such as Senate Bill 423 and Assembly Bill 2011 establish separate pathways for qualifying housing projects.

However, the court decided a dispute involving California’s ADU statutes and a claim under the Government Claims Act. It did not rule directly on SB 423 or AB 2011. Whether the reasoning affects disputes under those laws will depend on their specific provisions and future court decisions.

Practical Takeaway

Homeowners considering an ADU should submit a complete application, review California’s current ADU requirements and keep a detailed written record of the permitting process. If a city appears to be imposing procedures or delays that conflict with state law, an ADU specialist or California land-use attorney can help assess the available options.

The ruling is a significant reminder that state housing laws can create enforceable duties for local governments. But homeowners should not assume that a delayed permit automatically means their project is approved or that damages are guaranteed. The applicable statute, application status, reason for the delay and facts of each case still matter.

For official guidance, homeowners can consult the California Department of Housing and Community Development’s ADU resources and review Government Code Section 66317.