Accessory Structures in Orange County, CA (2026)

5 county-level rules, plus city-specific rules for 10 cities in Orange County, California.

Verified from official government sources

Note: These county rules apply to unincorporated areas of Orange County. If you live within an incorporated city, that city's own rules apply: see the city list below.

ADU Rules

Unincorporated Orange County allows ADUs and JADUs through a ministerial permit under Section 7-9-90, capping detached units at 1,200 square feet, or 800 square feet within setback areas, with a 16-foot height limit and 4-foot setbacks.

Orange County ADU Permits: Size and Setback Rules

Some Restrictions

Orange County Codified Ordinances § 7-9-90

...the property owner may establish through a ministerial permit process an attached or detached accessory dwelling unit and/or a junior accessory dwelling unit... A newly constructed attached or detached accessory dwelling unit, located within the building site area, shall not exceed twelve hundred (1,200) square feet in size.

Full ordinance details →Official source ↗

ADU Owner Occupancy

Unincorporated Orange County requires the building site's owner to occupy a dwelling unit whenever a junior accessory dwelling unit is built there.

Orange County JADU Owner-Occupancy Rule

Some Restrictions

Orange County Codified Ordinances § 7-9-90

(3)A property owner may establish one (1) junior accessory dwelling unit proposed within an existing or proposed primary dwelling...b.A junior accessory dwelling unit shall not exceed five hundred (500) square feet in size.c.The building site's owner shall occupy a dwelling unit on the building site.d.The junior accessory dwelling unit shall comply with Government Code Section 65852.22, as may ...

Full ordinance details →Official source ↗

ADU Rental Restrictions

Accessory dwelling units and junior ADUs in unincorporated Orange County may only be rented long-term, for stays of 30 days or more; renting either as a short-term rental under 30 days is prohibited under the county zoning code.

Orange County ADU Short-Term Rental Ban

Significant Restrictions

Orange County Codified Ordinances § 7-9-90(c)(5)

The accessory or junior accessory dwelling unit is not intended for sale separate from the primary dwelling but may be rented as a long-term rental (more than thirty (30) days). The accessory or junior accessory dwelling unit(s) shall not be used as a short-term rental (less than thirty (30) days).

Full ordinance details →Official source ↗

Shed & Carport Rules

In unincorporated Orange County, garages and carports must meet the same setback lines as the main house, unless placed along an alley or within the interior side or rear yard under specific exceptions in the zoning code.

Orange County Carport Setback Rules

Some Restrictions

Orange County Codified Ordinances § 7-9-70.3(d)

(d)Garages and carports. The placement or construction of garages and carports on any building site used for residential purpose...shall comply with the setback requirements for a main building except as otherwise specified as follows...(3)Detached garages and carports...may be placed or constructed any place within the required rear or interior side setback area except within those areas where...

Full ordinance details →Official source ↗

Garage Conversions

Converting a required garage parking space into living area in unincorporated Orange County is allowed only under a new-construction permit, and the owner must replace the removed parking space elsewhere on site.

Orange County Garage Conversion Parking Rules

Some Restrictions

Orange County Codified Ordinances § 7-9-70.3

Note: For purposes of this section this is only applicable for permits deemed as new construction; however, the conversion of a required parking space to living area will require replacing the removed parking space:

Full ordinance details →Official source ↗