Calabasas Wanted Your ADU to Match the House. HCD Said No.

You've got the backyard ADU drawn up — floor plan, elevations, the works. Then the plan checker sends it back: the unit has to look like your main house. In Calabasas, that instruction wasn't one reviewer's preference. It was written into the city's ADU ordinance, which told homeowners the new unit's design had to "conform in general to the design of the primary dwelling."

HCD has now told Calabasas that rule can't stand — and it's one item on a long list.

Here's the thing: an ADU gets approved ministerially — no design board, no hearing, no judgment call. Because there's no room for judgment, the standards a city applies have to be objective: measurable against a fixed benchmark, not a reviewer's taste. A rule that asks whether your ADU "conforms in general" to the house is exactly the kind of subjective test HCD's position says state law doesn't allow.

What HCD told Calabasas about the design mandate

In its May 4, 2026 findings letter, HCD quoted the ordinance's design language — "The design of the unit shall conform in general to the design of the primary dwelling" — and held it up against the statute. State ADU Law lets a city "Impose objective standards on accessory dwelling units that include, but are not limited to, parking, height, setback, landscape, architectural review, maximum size of a unit" (Gov. Code § 66314). HCD, quoting the statutory definition, described an objective standard as one that involves "no personal or subjective judgment by a public official and are uniformly verifiable by reference to an external and uniform benchmark or criterion available and knowable by both the development applicant or proponent and the public official prior to submittal."

"Conform in general" doesn't clear that bar. HCD's finding was blunt: requiring the ADU's design to conform to the primary dwelling is "overreaching, ambiguous and subjective." In HCD's view, the city must strike the requirement.

Verified against HCD's ADU Ordinance Findings letter to the City of Calabasas, dated May 4, 2026 (Finding 8, Calabasas ADU Ordinance No. 2020-382, § 17.12.170 C.3).

The design rule was one of 20 numbered findings

The design mandate is the headline, but it's finding 8 of 20 numbered findings in the letter. Two more are worth knowing, because they hit ADU applicants before design ever comes up.

The zoning-clearance requirement. Calabasas's ordinance said a single ADU "may be allowed on a legal lot… subject to a zoning clearance." HCD's position: that extra step isn't allowed. Government Code § 66321, subdivision (b)(3) prohibits "Any requirement for a zoning clearance or separate zoning review," and a city has just 60 days to approve or deny an ADU application when there's an existing home on the lot. As HCD put it, "Requiring a separate zoning clearance or review is unauthorized by State ADU Law and would thwart the 60-day approval deadline."

The zone exclusion. The ordinance's land-use table left ADUs off the permitted list in two of the city's residential zones — REC and CMU. HCD found that a problem: state law requires a local agency to "ministerially approve an application for a building permit within a residential or mixed-use zone" to create an ADU (Gov. Code § 66323). Because "REC and CMU zones are residential zones," HCD told the city it "must amend the Ordinance to list ADUs as permitted uses in REC and CMU zones."

What this means for your project

If you're building in Calabasas — or anywhere a local ADU ordinance is still on the books unrevised — the rulebook at the counter may be out of step with state law. A "conform in general" or "match the house" design demand, a separate zoning clearance, a zone that quietly leaves ADUs off the permitted-use list: HCD has flagged all three here as things the city must fix. That doesn't mean nothing applies. Genuinely objective standards — a height limit, four-foot side and rear setbacks, a published materials list — still stand.

One caution: an HCD findings letter is HCD's interpretation of state law, not a court ruling. The city gets 30 days to respond and can either amend the ordinance or defend it, and courts have the final say. So confirm your jurisdiction's current ADU ordinance, and run your specific situation past your local planning department or an attorney. Treat this as background, not 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.