Guide · unpermitted ADUs
If your unpermitted ADU or JADU was built before January 1, 2020, a California city cannot deny it a permit over building standard violations unless they pose a genuine health and safety threat, and it cannot charge you impact fees or utility connection or capacity charges for legalizing it. That is Gov. Code § 66311.7. Until January 2026 it was numbered § 66332, so most of what you will read about it, including some city handouts, cites a section that no longer exists.
Three protections, each of which changes the economics of coming clean:
Denial is off the table for ordinary code issues. The agency may not deny the legalization permit for violations of building standards that do not present a health and safety threat. A pre-2020 unit built to older practice does not have to meet today's code line by line to be permitted.
No impact fees, no connection charges. The homeowner shall not be required to pay impact fees or utility connection or capacity charges to legalize the unit, with narrow statutory exceptions. For a unit that already exists, the usual five-figure fee stack largely disappears.
A confidential inspection first. The statute lets you commission a third-party code inspection, confidentially, before you file anything. You learn what the deficiencies are and what fixing them costs while the city still knows nothing, which converts the scariest unknown in the process into a priced list. Read § 66311.7 →
“shall not deny an application for a permit to create an accessory dwelling unit due to the correction of nonconforming zoning conditions, building code violations, or unpermitted structures that do not present a threat to public health and safety”
Gov. Code § 66322(b) · verified against leginfo
This closes the classic trap: you apply to legalize the unit, and the city responds with a list of everything else on the parcel. Unless an item is a health and safety threat, it is not a lawful ground for denial.
You cannot legally rent it, an appraiser cannot count it, an insurer can decline the claim that involves it, and a buyer's lender can force the question at the worst possible moment, in escrow. The legalization statute exists because the state wants these units on the books; the leverage it hands homeowners is real, but it only helps the ones who use it.
SB 543 renumbered this part of the ADU chapter effective January 1, 2026: § 66332 became § 66311.7. An earlier recodification in 2024 moved the whole chapter out of § 65852.2. Any guide, city handout, or AI answer citing the old numbers was written against text that has since moved, and may be stale in other ways too. Paste any citation into the citation checker to see whether it still resolves, or read what SB 543 changed.
Units built on or after January 1, 2020 get no protection from this section. Genuine health and safety threats, structural, fire egress, electrical, must be corrected regardless, and that work is yours to fund. And the section governs the permit decision, not taxes: expect the assessor to learn the unit exists.
The rules above are the statewide floor. What you can build also depends on your jurisdiction's compliance status and your lot. The feasibility check resolves both and returns a size range with the governing section for every figure.