Often, yes. As of October 2026, state law bars a city from denying a permit for an unpermitted ADU built before January 1, 2020, only because it breaks building standards or ADU rules. The exceptions are corrections needed to protect health and safety, or a building found substandard. Most legalizations still involve some repair work.
What does state law protect?
Government Code §66311.7 says a local agency cannot deny a permit for an unpermitted ADU built before January 1, 2020, solely because it violates building standards or does not meet state or local ADU rules.
Government Code §66322(b) also limits denials over nonconforming zoning or code issues that do not threaten health and safety and are not affected by the ADU.
When can the city still require changes?
When it finds that a correction is needed to protect public health and safety, or when the building is substandard under Health and Safety Code §17920.3.
Agencies must publish a checklist of substandard conditions and information on confidential third-party inspections.
What if the unit was built after 2019?
The pre-2020 protection does not apply. The unit is reviewed like a new ADU, so it must meet current codes and ADU standards.
What does legalizing usually involve?
- Measured drawings of the unit as it stands.
- An inspection of wiring, plumbing, gas, smoke and carbon monoxide alarms, and exits.
- Opening walls where the inspector needs to see framing or connections.
- Repairs for any health and safety items, then permit sign-off.
Is a converted garage without permits common?
It is a frequent case. A garage converted years ago without permits can often be brought into the system rather than torn out, if it meets health and safety standards.
See garage conversions for the upgrades involved.
When is legalizing harder than it sounds?
It depends on what is behind the walls and when it was built. Proving a pre-2020 build date, dealing with unsafe wiring or a missing exit, or finding a sewer line run without permits can add work. A confidential third-party inspection can show the scope before you involve the city. We can walk the unit and tell you what we see.
Related
Sources, as of October 2026: California Government Code §§66311.7 and 66322; Health and Safety Code §17920.3; HCD ADU Handbook (March 2026). General information, not legal advice.
Updated October 2026