His ADU Permit Took 3 Years. Now the City Can Be Sued for It.

A backyard accessory dwelling unit, photographed for the state's ADU program page. Photo via California Department of Housing and Community Development.

Wei Shi applied for an ADU permit in Palos Verdes Estates in 2020 and says the city answered with a conditional use permit demand, discretionary review, and a homeowners association art jury before approving it in 2023. On October 23, 2026, a California appeals court ruled that a city that breaks its mandatory duty to approve an ADU permit ministerially can be sued for damages, reviving Shi's claim of more than $1 million in losses.

The short version:

• In Shi v. City of Palos Verdes Estates (B350195), the Second Appellate District held that ADU permit applicants are the direct and intended beneficiaries of the state's ministerial approval duty, so they can sue under Government Code Section 815.6 when a city breaches it.
• The opinion is certified for publication, which makes it binding on trial courts across California, not only in Los Angeles County.
• Nothing has been awarded yet. The ruling reverses a dismissal, and Shi still has to prove the delay and the losses back in trial court.

From the text

The case turned on one question: when the Legislature told cities to approve ADU permits ministerially and on a clock, whom was it protecting? The city said the public at large, in the form of more housing. The court said the person holding the application.

Significantly, section 66317 does not place a duty upon local agencies to alleviate the housing crisis. Rather, section 66317 places a duty on local governments to consider and approve permits ministerially. Thus, as we explained above, permit seekers are the direct and intended beneficiaries of the relevant duty.

Shi v. City of Palos Verdes Estates (Cal. Ct. App., Oct. 23, 2026) B350195, slip op. at p. 10

What changed

California's ADU statutes have always told cities what to do and never said what happens when they do not. Government Code Section 66317 says an ADU application "shall be considered and approved ministerially without discretionary review or a hearing," and that the city "shall either approve or deny the application" within 60 days of receiving a completed one when a home already stands on the lot. It also bars any local rule other than a compliant ADU ordinance from being "the basis for the delay or denial" of the permit. What it does not contain is a penalty.

Shi did not need one. He sued under Section 815.6 of the Government Claims Act, which makes a public entity liable when it fails a mandatory duty that an enactment imposes "to protect against the risk of a particular kind of injury." The court put it plainly, borrowing from the state Supreme Court: it is Section 815.6, not the ADU statute, that creates the right to sue. The ADU law only has to supply the duty, and the court held it does.

Translate the timeline and it gets uncomfortable fast. Roughly three years is about 18 back-to-back 60-day clocks. Shi's complaint lists what that cost him: lost use of the property, higher construction costs, interest, design fees, and diminished value. Those are allegations, not findings. The city's demurrer did not dispute that the duty was mandatory or that the delay caused the harm, so the appeal never reached those questions.

Two limits keep this from being a blank check. First, Section 815.6 lets a city escape liability if it shows it "exercised reasonable diligence to discharge the duty," so a city that was genuinely working the file is in a different spot from one that invented hurdles. Second, the 60-day clock only starts on a completed application, and admitting an application is complete is not what permit counters do best. That is why the completeness step, which SB 543 now puts on its own 15-business-day timeline, matters as much as the approval step.

Who wins and who loses

Homeowners with a stalled file. If you're a first-time ADU client whose application has sat past the clock while the city asks for things the statute forbids, such as a use permit, a design board, or a hearing, you now have a damages theory alongside the old remedy. Before this ruling, the trial court had pointed applicants to a writ of mandate, the route that worked in Riddick v. City of Malibu (2024): a court order forcing approval. A writ gets you the permit. It does not pay for the three years.

Cities that treat the clock as advisory. The exposure is now money, not just a court order. UC Davis law professor Chris Elmendorf wrote, as HousingWire reported, that the same logic could reach other ministerial housing laws, listing SB 35, SB 423, AB 2011, SB 684, and SB 1123. That reach is his read, not the court's holding, but the opinion's reasoning does not depend on anything unique to ADUs.

Private review boards. Shi alleges the city sent him to the Palos Verdes Homes Association Art Jury. Section 66317 already said no local policy other than a compliant ADU ordinance can be the basis for delay. A city that routes ministerial files through a design jury is now taking a priced risk.

The cross-street check. Because this is a California published opinion, it reaches the Los Angeles, San Francisco, and San Diego reader alike; an SF owner on either the Waiver or the No-Waiver track, or a San Diego owner working the 30-day lane for pre-approved plans we mapped in July, now has a damages backstop if the city stalls a compliant file. It stops at the state line. Washington's HB 1337 and Oregon's SB 1051 tell cities what they must allow, but whether a Seattle or Portland homeowner could sue for delay depends on each state's own tort-claims law, and we have not seen a court in either state answer that. New York City is a different animal again: most ADU filings there go through DOB NOW with a licensed architect, and we know of no New York ruling that puts a dollar figure on a slow review. The open question for those markets is whether a statutory clock with no price attached is a clock at all.

Our read: the 60-day clock was always the law, and it was routinely treated as a suggestion because missing it cost a city nothing. This ruling puts a price on it, and we expect city attorneys, not planners, to start enforcing the clock internally, because the risk now shows up in their budget. That pressure will hit hardest where Shi's did, in places that kept a discretionary step in front of a ministerial permit.

What to watch

The city can still ask for rehearing or for California Supreme Court review, and the case goes back to the trial court either way. For your own project, the practical lesson is documentation. Keep the date the city accepted your application as complete, every written request for something beyond the ADU ordinance, and every invoice the delay added. The Government Claims Act also has its own claim-filing deadlines, and they are short, so talk to a lawyer before assuming you can wait. And if you would rather never test the clock at all, the fastest lane is still a plan the city already approved: as we covered when the 2026 code reset California's pre-approved catalogs, those plans carry a 30-day decision deadline, half the standard clock.

If you want to start from that faster lane, A-du's build marketplace lists pre-approved ADU plans from city and county catalogs and design firms, with an estimated build cost for each.

The next filing to watch is the trial court's: the first damages number a California court attaches to a missed ADU clock will tell every city exactly what the 60 days are worth.

Elsewhere on the ADU beat

• Montgomery County, Maryland's executive vowed to veto a bill that would drop the owner-occupancy rule for ADU rental licenses and waive some permit fees, Bethesda Magazine.
• Hancock, Maryland adopted an ADU ordinance to meet the state's October 1, 2026 deadline for allowing ADUs on single-family lots, The Hancock News.