Placentia, CA Accessory Structures: Garage Conversions (2026)
Garage conversion rules in Placentia, CA, sometimes called garage-to-ADU or accessory living unit conversions, govern permits, ceiling height, egress, and parking replacement.
Key Facts
- Approval standard
- Ministerial approval for space within existing structure
- Expansion for ingress and egress
- Up to 150 square feet in an accessory structure
- Required access
- Exterior access separate from the main dwelling
- Replacement parking when garage is converted
- None required for the primary structure
- Junior ADU size limit
- 500 interior livable square feet
- Multifamily garages and storage areas
- Up to 25 percent of units, at least one
Summary
In the City of Placentia, California, Section 23.73.080 requires ministerial approval of an accessory or junior dwelling unit built within the existing space of a single-family dwelling or accessory structure, which covers a garage. The conversion needs separate exterior access, fire-safe side and rear setbacks, and allows up to 150 square feet of expansion for ingress and egress.
(1) Notwithstanding any other provision of this chapter, the city shall ministerially approve an application for any of the following accessory dwelling units within a residential or mixed-use zone: (A) A junior and/or accessory dwelling unit within the existing or proposed space of a single-family dwelling or accessory structure. (i) An expansion of up to one hundred fifty (150) square feet shall be allowed in an accessory structure solely for the purposes of accommodating ingress and egress. (ii) The junior or accessory dwelling unit shall have exterior access separate from the existing or proposed single-family dwelling. (iii) The side and rear setbacks shall be sufficient for fire and safety. ... (C) On a lot with a multifamily dwelling structure, up to twenty-five (25) percent of the total multifamily dwelling units, but no less than one (1) unit, shall be allowed within the portions of the existing structure that are not used as livable space, including, but not limited to, storage rooms, boiler rooms, passageways, attics, basements, or garages, provided that each unit complies with state building standards for dwellings.
Full Breakdown
The Placentia Municipal Code does not have a stand-alone garage conversion chapter. A garage becomes living space through Chapter 23.73 as an accessory dwelling unit or junior accessory dwelling unit. Section 23.73.080(1)(A) says the city shall ministerially approve a junior and/or accessory dwelling unit within the existing or proposed space of a single-family dwelling or accessory structure. Up to 150 square feet of expansion is allowed in an accessory structure solely to accommodate ingress and egress. The unit needs exterior access separate from the single-family dwelling, and the side and rear setbacks must be sufficient for fire and safety. A junior unit must also meet Section 23.73.090, which allows one junior unit of up to 500 interior livable square feet within the footprint of a single-family dwelling, including an attached garage.
Section 23.73.060(2)(N) relaxes the standards for a unit entirely within a lawfully existing accessory structure that has independent exterior access: it need not meet lot coverage, maximum height or parking requirements, and the setback is only what fire safety standards require. Section 23.73.060(2)(B)(iii) says a unit built in the same location and to the same dimensions as an existing garage needs no setback beyond what the garage already has. The 10 foot separation between buildings does not apply to existing structures converted to an ADU.
Parking is the question most owners ask. Under Section 23.73.060(2)(F), when a garage, carport or covered parking structure is demolished for an ADU or converted to one, no replacement parking for the primary structure is required. A detached garage that is replaced by an ADU gets its demolition permit reviewed with the ADU application and issued at the same time, under Sections 23.73.030(c)(4) and 23.73.070(6).
On a lot with a multifamily dwelling structure, Section 23.73.080(1)(C) allows up to 25 percent of the units, and no fewer than one, within garages and other non-livable portions, as long as each unit meets state building standards for dwellings.
Violations & Fines
Converting a garage without meeting Chapter 23.73 is a Title 23 violation that the city can charge as a misdemeanor or an infraction under Section 1.08.020, with infraction fines capped at $100, $200 and $500 for a first, second and each additional violation within one year. Under Section 23.73.070(5), until January 1, 2030, a correction notice for an ADU building violation must tell the owner they can apply to the development services department to delay enforcement five years if correction is not needed for health and safety.
Frequently Asked Questions
Can I convert my garage to an ADU in the City of Placentia?
Do I have to replace the parking spaces from a converted garage?
Can I add on when converting a detached garage?
What if I tear down a detached garage and build an ADU?
Sources & Official References
Other rules in Placentia
California rules heatmap·Compare Placentia to another location·View the California accessory structures overview
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Garage Conversions in Nearby Cities
How other cities in Orange County handle garage conversions.