County directory

Orange County ADU rules

Each place name links to that city or county's own ADU page. Places with a 'See our rules summary' button also have our plain-language summary of the local ADU rules, with sources. Each place below says whether we show local rules or California state rules.

Places in Orange County

Aliso Viejo (opens the government site in a new tab)See our rules summary
Showing California state rules, plus Aliso Viejo details
The size, setback, height, and parking figures are California state rules. The Aliso Viejo section lists the local details we have on file, like plans, forms, and contacts.
Anaheim (opens the government site in a new tab)See our rules summary
Showing California state rules because Anaheim's local rules may conflict with state law or are being challenged
The size, setback, height, and parking figures are California state rules. The Anaheim section lists the local details we have on file, like plans, forms, and contacts.
Where a Anaheim rule may conflict with state law or is being challenged, we show the California state rule instead. This covers owner-occupancy rules for junior ADUs.
Brea (opens the government site in a new tab)See our rules summary
Showing Brea city rules
These are Brea's own ADU rules on file, shown with the California state rules they build on. Each item says which is which.
Where a Brea rule may conflict with state law or is being challenged, we show the California state rule instead. This covers a 10-foot separation between a detached ADU and the main home, and a rule that a detached ADU may not sit closer to the street than the front wall of the main home.
Buena Park (opens the government site in a new tab)
Showing California state rules
We couldn't read this city's ADU code yet, so we're showing California state rules. Check with the city before you plan.
City ADU page: https://www.buenapark.com/city_departments/community_development/planning_division/Accessory_Dwelling_Unit_ADU/Junior_Accessory_Dwelling_Unit_(JADU)_Regulations.php
Costa Mesa (opens the government site in a new tab)See our rules summary
Showing Costa Mesa city rules
These are Costa Mesa's own ADU rules on file, shown with the California state rules they build on. Each item says which is which.
Where a Costa Mesa rule may conflict with state law or is being challenged, we show the California state rule instead. This covers owner-occupancy rules for junior ADUs, a rule that keeps most new ADUs on the first floor unless extra conditions are met, and a 6-foot building separation.
Cypress (planning page) (opens the government site in a new tab)
Showing California state rules because Cypress's local rules may conflict with state law or are being challenged
We show the state rules for an ADU ordinance on file from 2023 that state housing department letters from May 2025 and May 2026 say may not meet current state law. Check with Cypress about how it handles this today.
Dana Point (planning page) (opens the government site in a new tab)
Showing California state rules
We couldn't read this city's ADU code yet, so we're showing California state rules. Check with the city before you plan.
Planning page: https://www.danapoint.org/City-Government/Community-Development/Planning
Fountain Valley (opens the government site in a new tab)
Showing California state rules because a local rule change is pending
A local rule change is pending. The City says changes to its ADU rules are pending, after a December 2024 state housing department letter on its 2023 rules. We'll add the new local rules after they take effect and we've reviewed them.
Fullerton (opens the government site in a new tab)See our rules summary
Showing Fullerton city rules
These are Fullerton's own ADU rules on file, shown with the California state rules they build on. Each item says which is which.
Where a Fullerton rule may conflict with state law or is being challenged, we show the California state rule instead. This covers a one-ADU-and-one-junior-ADU limit on most single-family lots and owner-occupancy rules for junior ADUs.
Garden Grove (opens the government site in a new tab)See our rules summary
Showing California state rules, plus Garden Grove details
The size, setback, height, and parking figures are California state rules. The Garden Grove section lists the local details we have on file, like plans, forms, and contacts.
Huntington Beach (opens the government site in a new tab)
Showing California state rules because Huntington Beach's local rules may conflict with state law or are being challenged
We show the state rules for its ADU rules, which are part of an ongoing dispute with the state over housing laws (the City says its zoning code ADU section is no longer in effect), and a coastal development permit for Coastal Zone ADUs. Check with Huntington Beach about how it handles this today.
Irvine (planning page) (opens the government site in a new tab)See our rules summary
Showing California state rules, plus Irvine details
The size, setback, height, and parking figures are California state rules. The Irvine section lists the local details we have on file, like plans, forms, and contacts.
La Habra (opens the government site in a new tab)
Showing California state rules because La Habra's local rules may conflict with state law or are being challenged
We show the state rules for a one-ADU-and-one-junior-ADU limit on single-family lots and a two-detached-ADU limit on multifamily lots. Check with La Habra about how it handles this today.
La Palma (planning page) (opens the government site in a new tab)
Showing California state rules because La Palma's local rules may conflict with state law or are being challenged
We show the state rules for an ADU ordinance on file from 2023 that a May 2026 state housing department letter says may be outdated. Check with La Palma about how it handles this today.
Laguna Beach (opens the government site in a new tab)
Showing California state rules because a local rule change is pending
A local rule change is pending. Laguna Beach's ADU rules are a temporary (urgency) ordinance that leaves out some recent state law changes until the California Coastal Commission approves a permanent ordinance. We'll add the new local rules after they take effect and we've reviewed them.
Laguna Hills (opens the government site in a new tab)See our rules summary
Showing California state rules, plus Laguna Hills details
The size, setback, height, and parking figures are California state rules. The Laguna Hills section lists the local details we have on file, like plans, forms, and contacts.
Laguna Niguel (opens the government site in a new tab)
Showing California state rules because Laguna Niguel's local rules may conflict with state law or are being challenged
We show the state rules for a one-ADU-and-one-junior-ADU limit on single-family lots (part of the city is in the Coastal Zone, where coastal rules may also apply). Check with Laguna Niguel about how it handles this today.
Laguna Woods (planning page) (opens the government site in a new tab)
Showing California state rules because Laguna Woods's local rules may conflict with state law or are being challenged
We show the state rules for an ADU ordinance on file from 2020 that a December 2025 state housing department letter says may be outdated. Check with Laguna Woods about how it handles this today.
Lake Forest (planning page) (opens the government site in a new tab)See our rules summary
Showing Lake Forest city rules
These are Lake Forest's own ADU rules on file, shown with the California state rules they build on. Each item says which is which.
Los Alamitos (opens the government site in a new tab)See our rules summary
Showing California state rules, plus Los Alamitos details
The size, setback, height, and parking figures are California state rules. The Los Alamitos section lists the local details we have on file, like plans, forms, and contacts.
Mission Viejo (planning page) (opens the government site in a new tab)
Showing California state rules because Mission Viejo's local rules may conflict with state law or are being challenged
We show the state rules for owner-occupancy rules for junior ADUs, a deed restriction against selling any ADU, a 20-foot single-story limit for detached ADUs, architectural-compatibility rules, and a rule keeping detached ADUs in the rear half of the lot. Check with Mission Viejo about how it handles this today.
Newport Beach (opens the government site in a new tab)See our rules summary
Showing Newport Beach city rules
These are Newport Beach's own ADU rules on file, shown with the California state rules they build on. Each item says which is which.
Where a Newport Beach rule may conflict with state law or is being challenged, we show the California state rule instead. This covers owner-occupancy rules for junior ADUs, a two-detached-ADU limit on lots with existing multi-unit homes, and limits on where ADU parking can go.
Orange (code) (opens the government site in a new tab)See our rules summary
Showing Orange city rules
These are Orange's own ADU rules on file, shown with the California state rules they build on. Each item says which is which.
Where a Orange rule may conflict with state law or is being challenged, we show the California state rule instead. This covers a 50% size cap that the city applies to detached ADUs too.
Placentia (opens the government site in a new tab)See our rules summary
Showing Placentia city rules
These are Placentia's own ADU rules on file, shown with the California state rules they build on. Each item says which is which.
Where a Placentia rule may conflict with state law or is being challenged, we show the California state rule instead. This covers limits on combining ADU types, a size cap for attached ADUs without the state minimum, and design rules about architectural style and entrances.
Rancho Santa Margarita (planning page) (opens the government site in a new tab)
Showing California state rules
We couldn't read this city's ADU code yet, so we're showing California state rules. Check with the city before you plan.
Planning page: https://www.cityofrsm.org/197/Forms-Handouts
San Clemente (planning page) (opens the government site in a new tab)
Showing California state rules
We couldn't read this city's ADU code yet, so we're showing California state rules. Check with the city before you plan.
Planning page: https://www.sanclemente.gov/240/Planning-Services
San Juan Capistrano (opens the government site in a new tab)See our rules summary
Showing California state rules, plus San Juan Capistrano details
The size, setback, height, and parking figures are California state rules. The San Juan Capistrano section lists the local details we have on file, like plans, forms, and contacts.
Santa Ana (opens the government site in a new tab)See our rules summary
Showing Santa Ana city rules
These are Santa Ana's own ADU rules on file, shown with the California state rules they build on. Each item says which is which.
Seal Beach (opens the government site in a new tab)See our rules summary
Showing California state rules, plus Seal Beach details
The size, setback, height, and parking figures are California state rules. The Seal Beach section lists the local details we have on file, like plans, forms, and contacts.
Stanton (planning page) (opens the government site in a new tab)
Showing California state rules because Stanton's local rules may conflict with state law or are being challenged
We show the state rules for an ADU ordinance on file from 2023 that a May 2026 state housing department letter says may be outdated. Check with Stanton about how it handles this today.
Tustin (opens the government site in a new tab)
Showing California state rules because a local rule change is pending
A local rule change is pending. The City introduced a new ADU ordinance (Ordinance 1578) in July 2026, and the adopted text could not be confirmed when this research summary was prepared. We'll add the new local rules after they take effect and we've reviewed them.
Villa Park (planning page) (opens the government site in a new tab)
Showing California state rules
We couldn't read this city's ADU code yet, so we're showing California state rules. Check with the city before you plan.
Planning page: https://villapark.org/Departments/Planning
Westminster (opens the government site in a new tab)See our rules summary
Showing California state rules because Westminster's local rules may conflict with state law or are being challenged
The size, setback, height, and parking figures are California state rules. The Westminster section lists the local details we have on file, like plans, forms, and contacts.
Where a Westminster rule may conflict with state law or is being challenged, we show the California state rule instead. This covers owner-occupancy rules for junior ADUs and a separate water meter for every ADU.
Yorba Linda (opens the government site in a new tab)
Showing California state rules because Yorba Linda's local rules may conflict with state law or are being challenged
We show the state rules for an ADU ordinance on file from 2020 that a December 2025 state housing department letter says may be outdated. Check with Yorba Linda about how it handles this today.
Unincorporated Orange County (opens the government site in a new tab)See our rules summary
Showing Orange County rules
These are Orange County's own ADU rules on file, shown with the California state rules they build on. Each item says which is which.

All counties in the ADU directory