Monterey Park, CA Accessory Structures: ADU Rules (2026)

Monterey Park's ADU chapter, Chapter 21.50 of the Municipal Code, was rewritten by Ordinance 2261 on April 16, 2025, replacing the city's 2020 ADU ordinance (Ord. 2192). Section 21.50.010 defines the terms that drive the rest of the chapter: a "primary dwelling" is the residential structure on the parcel that first received a valid certificate of occupancy, or the largest residential structure if that history is unclear, and "tandem parking" means two or more cars parked one behind the other. Section 21.50.020(A) sets the sequencing rule at the center of enforcement: the Building Official cannot issue a final certificate of occupancy for an ADU or JADU until the primary dwelling on the lot already has one, and before any ADU/JADU final, the owner must record a covenant running with the land at the County Recorder's office.

Section 21.50.020(B) requires the City Attorney to approve that covenant's form before it is recorded. A related requirement sits in Section 21.50.030: any ADU or JADU with its own exterior entrance or a separate utility connection must have an address number application submitted, with the number posted where it is visible from the street, and the Fire Chief can require additional address markers to speed emergency response to the unit. Because Chapter 21.50 sits under Title 21 (Zoning), a violation is generally treated as an infraction rather than a straight misdemeanor under the city's general penalty scheme.