Two ADU pathways stack: the state list isn't your ceiling

You're a homeowner or designer mapping out an ADU, and someone hands you "the state list" — the units California says a city has to approve ministerially. You read it as the ceiling. One ADU and one JADU inside the single-family footprint, maybe a detached unit with four-foot setbacks, and that's the box. So you design to it. And if a converted-garage ADU already sits on the lot, you assume the door is closed on anything else.

Here's the thing: the state list is a floor, not a ceiling — and HCD has told city after city in 2026 that a second, separate pathway stacks on top of it.

Two pathways, not one

California ADU law runs on two tracks. Government Code section 66323 is the mandatory list — the units a local agency "shall ministerially approve" in a residential or mixed-use zone, in any combination (the converted ADU, detached ADU, and JADU most people picture). Section 66314 is the other track: at least one ADU built to the city's own objective development standards, in any format — attached, converted, or detached.

HCD's position is that these two are cumulative. A city can't count a 66314 unit toward the 66323 list, and it can't close the 66323 list just because a 66314 unit already exists. You get the full 66323 allotment and at least one 66314 unit — on single-family and multifamily lots alike.

Larkspur drew the bright line

Larkspur's ordinance capped a lot at "two (2) total ADUs and one (1) JADU," blocked a new attached ADU where a detached or converted ADU already existed, and funneled multifamily parcels into section 66323 review only. HCD found all of that out of step with state law. The language HCD used is the clearest statement of the rule on record:

"These two allowances are not mutually exclusive and must be authorized and combined to result in a cumulative maximum. This is true for both single-family primary dwellings and multifamily primary dwellings."

HCD's directive: amend the ordinance "to allow, on any lot with any primary dwelling, the full allotment of section 66323 units with at least one unit of any format authorized by section 66314."

Verified against HCD's Larkspur ADU Ordinance Findings Letter, dated July 7, 2026.

Not one city — a 2026 pattern

Larkspur isn't alone. Across the spring and summer of 2026, HCD made the same finding in ordinance review letters to jurisdiction after jurisdiction:

• Thousand Oaks (June 1, 2026): the ordinance made a 66314 unit "count toward the allowances provided for in section 66323," HCD found — so the city must "allow the full allotment of 66323 units and at least one unit described under section 66314."
• El Monte (June 24, 2026): HCD directed the city to "allow the full allotment of 66323 units and at least one 66314 unit."
• Martinez (July 14, 2026): a cap of "no more than two ADUs and one JADU" drew the finding that the city must "allow at least one ADU under section 66314 as well as all applicable ADUs under section 66323."
• Amador County (April 28, 2026): HCD's words — "Section 66323 units must also be combined, in any order, with at least one unit created subject to local development standards per section 66314."

Same defect, four more times: an ordinance that treats the state list as the whole story.

What it means for your lot

If a city hands you a unit count that stops at the 66323 list — or tells you a converted-garage ADU on the lot bars anything else — HCD's position is that the count is short by at least one 66314 unit. That's a barrier that may not be enforceable.

One caution, stated plainly: an HCD ordinance findings letter is HCD's interpretive position, not settled law. Courts are the final arbiter, and a city can respond with its own findings rather than amend. Treat these letters as a strong signal of enforcement risk, read your own ordinance against sections 66314 and 66323, and verify your specific lot with your jurisdiction and your own counsel before you rely on any of it. None of this is legal advice.

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.