What it changes for boards and managers

There are two entirely different duties here, and they land on two different kinds of association.

An existing board becomes a permitting gatekeeper. Under item 8, a member inside an existing association cannot get map approval without written authorisation from that association — approved at a duly noticed board meeting, and where required, by the membership.

That is a role most boards have never played, and it needs a process before the first request arrives: who receives the application, what the board is actually deciding, what record it keeps, and whether the governing documents require a membership vote.

What a board approves here carries consequences. Authorising a subdivision of a member's parcel into separately conveyable condominium units changes the association's membership count, its assessment base, its voting arithmetic and its insurance profile. It is a materially different decision from approving an ADU's construction — which, under Civil Code sections 714.3 and 4751, the association largely cannot refuse and cannot charge for.

And a new class of very small associations is being created by county permit. A homeowner who converts a garage and sells the ADU has, by the time the map records, formed a two-member common interest development with recorded CC&Rs, a dues obligation, an insurance obligation and a statutory governance regime.

Its first board is the homeowner and the person who bought the ADU. Neither is likely to know that they are now subject to the annual budget report requirements, the open meeting rules, the election statutes, the records inspection obligations, and the reserve study duty where major component replacement value reaches half the gross budget.

The section 4800 unincorporated route for three or fewer members reduces the corporate formalities. It does not exempt the association from the Davis-Stirling Act.

The tension with the rest of ADU law

Read alongside the statewide rules, the County's scheme sits in an interesting place.

The state has spent five years removing association control over ADUs. Sections 714.3 and 4751 void covenants that effectively prohibit or unreasonably restrict them, and AB 130 removed fees and other financial requirements from the definition of a reasonable restriction as of June 30, 2025. The Department of Housing and Community Development's March 2026 handbook says such CC&Rs, “including operating rules, are void and unenforceable.”

The County ordinance does not disturb any of that. What it regulates is the separate sale, which AB 1033 left to local option — and there the association's consent is required.

So a board in unincorporated San Diego County may not be able to stop a member building an ADU, and may nonetheless decline to authorise its separate conveyance. Those are different questions with different answers, and conflating them is a mistake.

AB 1033 remains opt-in, and most jurisdictions have not opted in

This is the part national coverage routinely gets wrong. AB 1033 authorises a local agency to adopt an ordinance permitting separate conveyance; it mandates nothing. Reporting identifies a small set of California jurisdictions that have adopted one — San Jose, the City of San Diego, Santa Monica, Santa Cruz, San Francisco, and now unincorporated San Diego County.

Everywhere else in California, an ADU cannot be sold apart from the primary dwelling, and a board asked about it should confirm its own jurisdiction's position rather than assume either answer.

What to watch next

Whether other counties copy the HOA-formation requirement. San Diego County's approach solves a real problem — two separately owned dwellings on one lot need a mechanism for shared roofs, driveways and insurance — and Davis-Stirling is the mechanism California already has.

Also worth watching: AB 956, on the Governor's desk, would raise from one to two the number of detached ADUs a local agency must ministerially approve on a lot with a proposed or existing single-family dwelling, while providing that ministerial approval of a junior ADU is not required where two detached ADUs already exist. A lot carrying a primary residence and two ADUs is a three-unit common interest development if the units are separately conveyed — which is where these two rules meet.