Is Your City's ADU Ordinance Outdated? HCD Is Asking Cities to Repeal
HCD is telling cities with outdated ADU ordinances to repeal or amend them. Here's what changed since 2023 — and what applies now.
You're designing an ADU. You pull up your city's ADU ordinance for the rules — the size cap, the setbacks, the owner-occupancy line — and build your whole plan around what it says. Here's the problem nobody warns you about: that ordinance may be years out of date, and the rules printed in it may not be the ones that actually apply to your permit.
Here's the thing: State ADU Law has changed so fast that California has started writing to cities and asking them to repeal their own ADU ordinances.
What HCD is actually doing
On May 11, 2026, the California Department of Housing and Community Development (HCD) sent the City of Mountain View a Letter of Technical Assistance. The opening line is the whole story:
"The most recent ADU ordinance on file for the City of Mountain View with the California Department of Housing and Community Development (HCD) is from 2023."
The letter then lays out more than a dozen changes to State ADU Law across 2023, 2024, and 2025 — new size rules, impact-fee limits, completeness deadlines, owner-occupancy changes — and asks the city, by June 10, 2026, to either explain how its 2023 ordinance still complies or hand over a plan and timeline to repeal or amend it. HCD's recommendation is explicit:
"HCD recommends that a local jurisdiction with a noncompliant ADU ordinance repeal the ordinance to provide clarity for ADU applicants who may otherwise rely on the outdated ordinance."
That last clause — "applicants who may otherwise rely on the outdated ordinance" — is you.
Why "repeal," not just "amend"
Because of a rule written into the statute itself. HCD's position, stated in the letter, is that a noncompliant ordinance doesn't just need fixing — it stops controlling:
"If an existing ADU ordinance fails to meet the requirements of State ADU Law, the ordinance is 'null and void' and the local jurisdiction must apply the standards set forth in State ADU Law until it adopts an ordinance that complies with state law (Gov. Code, § 66316)."
And since 2025 there's a second trigger. If a city doesn't submit an adopted ordinance to HCD within 60 days, or doesn't answer HCD's findings within 30 days, the letter notes that the ordinance is null and void and the agency must apply State ADU Law when permitting ADUs (Gov. Code, § 66326, subd. (d)).
To be clear about what this one letter does and doesn't say: HCD did not declare Mountain View's ordinance void. It said the ordinance "may be outdated" and asked the city to respond. The null-and-void language is the general rule HCD is pointing to — not a finding against any one project.
It's not just one city
La Quinta shows the other side of it. The city actually did the work — it adopted a new ADU ordinance (No. 618) on December 3, 2024 — and HCD's June 24, 2026 findings letter still flagged problems. The first one is pure staleness:
"The Ordinance contains several references to code sections that were deleted by Senate Bill (SB) 477, effective March 25, 2024."
Those deleted sections — the old 65852.2 numbering — were relocated into Government Code §§ 66310–66342. Those deletions took effect in March 2024 — months before La Quinta adopted its ordinance that December — so a brand-new ordinance can already cite statutes that no longer exist.
HCD also found La Quinta's completeness clock was wrong. The ordinance gave the city up to 60 days to approve or deny; state law, HCD noted, requires written notice of a completeness determination not later than 15 business days after the agency receives the application (Gov. Code, § 66317). If your city sits on your "is it complete?" answer for weeks, that's the deadline to know.
Verified against HCD's Letter of Technical Assistance to the City of Mountain View (May 11, 2026) and HCD's Ordinance Findings Letter to the City of La Quinta (June 24, 2026).
What this means for your project
The practical takeaway: a rule in your city's printed ADU code that is stricter than current state law may not be enforceable against you. HCD's position — grounded in the statute — is that a noncompliant ordinance is void and the state standards apply instead, which can mean a larger allowed unit or a faster completeness answer than your local code implies.
One caution, and it matters: HCD's letters are the agency's enforcement position, not a court ruling, and courts are the final word on what the law requires. Before you rely on any of this, confirm the current state standard and your city's status with your building department or your attorney. This isn't legal advice — it's a reason to ask the question.
What CrossBeam does with it
When the letter lands on your desk, CrossBeam turns it around the same day: what each item is actually asking, the code or law behind it, and a written response you can hand to your team or your attorney — the back-and-forth that used to eat weeks, done in a couple of hours.