Everything homeowners need to know about building an accessory dwelling unit in Anaheim - size limits, setbacks, permits, and how the city's own standards layer on top of California's statewide ADU law.
Last verified: August 2026
8/10 · ADU-friendly
1,200 sq ft*
Max ADU size
18 ft*
Max height
Not required
Owner-occupancy
By-right
Permit type
This page summarizes Anaheim Municipal Code Section 18.38.015 (Accessory Dwelling Units and Accessory Dwelling Units - Junior), together with California's statewide ADU law (Government Code Section 65852.2), for general reference - it is not legal advice. Regulations change; always confirm current requirements with the Anaheim Planning and Building Department before designing or applying for permits. See sources below.
Zoning & size requirements
What you're allowed to build
ADU type
Max size
Max height
Notes
Detached (new construction)
Up to 1,200 sq ft, but also capped by the underlying zone's minimum livable floor area (roughly 1,700 sq ft in the RH zones and 1,225 sq ft in the RS-2 through RS-4 zones) and cannot exceed the primary dwelling's own square footage
18 ft, plus 2 ft for a roof pitch matching the primary dwelling, or the height of the primary dwelling, whichever is greater
4 ft side/rear setback; eaves must stay at least 12 inches from the property line
Attached (new addition)
The lesser of 50% of the primary dwelling or 1,200 sq ft, with floor minimums of 850 sq ft (studio/one-bedroom) or 1,000 sq ft (two+ bedrooms)
Underlying zone standards
Can't sit closer to the street than the primary dwelling's front wall, except for garage conversions
Junior ADU (JADU)
500 sq ft maximum (150 sq ft minimum, plus up to 150 sq ft for a separate entrance)
Within existing primary structure
Owner-occupancy required only if the JADU shares sanitation facilities with the house; a covenant must be recorded with the Orange County Recorder before permit issuance
Allowed zoning districts
Single-family residential zones (RH-1, RH-2, RH-3, RS-1, RS-2, RS-3, RS-4) and multifamily zones citywide. Multifamily properties can add up to 8 detached ADUs on an existing lot, plus interior conversions of up to 25% of existing units. Confirm your parcel's zoning district with Anaheim Planning.
Additional standards
Setbacks, parking & other rules
Setbacks
4 ft from side and rear property lines for new construction; conversions of existing structures are exempt from structural setback requirements
Parking
No parking required for a studio ADU or a JADU; 1 space required for a one-bedroom-or-larger ADU, waived entirely if the ADU is within a half mile of a transit stop or meets other state-listed exemptions
Units per lot
A single-family lot can generally add one ADU plus one JADU in addition to the primary home; multifamily lots allow more. Exact stacking depends on your lot and any prior lot-split entitlements - confirm with Anaheim Planning.
Owner-occupancy
Not required for a standard ADU, under statewide law (AB 976, effective January 1, 2024). JADUs require it only when sanitation facilities are shared with the primary home.
Building code
Must meet the California Residential Code as locally adopted by Anaheim (2025 California Building Standards Code, effective January 1, 2026)
Rental rules
No separate ADU-specific rental license is required by the city; standard California landlord-tenant law applies. Confirm any short-term rental rules separately if that's the plan.
Ordinance history
How Anaheim's ADU rules got here
2017Statewide by-right ADU law takes effect. California Government Code Section 65852.2 begins requiring cities, including Anaheim, to approve most ADUs ministerially, and Anaheim starts updating its zoning code in response.
2020Ordinance No. 6483 adopted. Received by the state Department of Housing and Community Development on July 28, 2020, the ordinance implemented AB 68 and related 2019 state legislation, including ministerial approval of Junior ADUs.
2023Ordinance No. 6555 adopted. Adopted April 4, 2023, amending related chapters of the Anaheim Municipal Code's building and zoning titles.
2024Ordinance No. 6570 adopted, alongside statewide changes. Anaheim adopted a further local ADU ordinance update on March 19, 2024, the same year statewide AB 976 eliminated owner-occupancy requirements and SB 1211 allowed up to 8 detached ADUs on multifamily lots.
2025State review flags a compliance gap. An HCD review in March 2025 found provisions restricting ADUs on parcels with a prior two-unit development or urban lot split approval conflicted with state law, and required Anaheim to amend its ordinance to defer to state standards.
Worth knowing: Anaheim has become the most active jurisdiction in Orange County for AB 1033, the state law letting homeowners sell a detached ADU separately as a condominium, according to regional reporting. Orange County as a whole saw ADU permits climb from roughly 1,367 in 2024 to about 1,916 in 2025, a sign the local market keeps expanding even as Anaheim's added local size caps make some projects a bit more constrained than the state's blanket standards alone would allow.
Permit process
How Anaheim ADU permitting works
1
Pre-application eligibility check
Confirm your zone and the underlying floor-area cap that applies to detached accessory structures on your lot with Anaheim Planning before you design.
2
Prepare your plan set (or use ADU Express)
Standard applications need a site plan, floor plans and elevations for the ADU, and existing floor plans of the primary home; an expedited "ADU Express" review option exists for eligible projects.
3
Submit to the Planning and Building Department
The city issues a completeness determination within 15 business days of submittal.
4
Ministerial plan review
No public hearing is required. State law requires a decision within 60 days of a complete application, though local reporting suggests full review often runs closer to 10-14 weeks in practice once resubmittals are factored in.
5
Pay permit and applicable impact fees
ADUs of 750 sq ft or less are exempt from most local impact fees under state law; larger units and applicable school fees may add cost - confirm current amounts with the city.
6
Building permit & inspections
Once your building permit is issued, schedule the standard framing, plumbing, electrical, and final inspections as construction proceeds.
Fees and timelines are approximate and can vary by project type - confirm current figures with the Anaheim Planning and Building Department.
Budgeting
What it costs to build an ADU in Anaheim
Garage conversion
Roughly $70,000-$180,000, the least expensive path since the shell already exists
Basement conversion
Basements are uncommon in California construction generally, so this is a smaller category locally; where they exist, conversions run roughly $100,000-$220,000 based on regional contractor estimates
New detached ADU
Roughly $150,000-$350,000+ for a code-compliant, freestanding unit
City permit fees
Reported at roughly $3,500-$12,000 depending on project scope, plus applicable school and utility fees on units above the state's impact-fee exemption thresholds
Impact fees
ADUs of 750 sq ft or less are exempt from most local impact fees under state law (Government Code Section 66311.5); larger ADUs may owe proportional fees, and school fees can apply above 500 sq ft of livable area
These are general ranges from local contractor estimates and regional reporting, not quotes - actual cost depends heavily on lot conditions, finishes, and whether your detached ADU bumps into Anaheim's underlying zone floor-area cap, which can force a smaller, less efficient footprint on some lots.
Before you apply
Tips for a smooth approval
Check the underlying zone's floor-area cap before you finalize a size. Anaheim ties the maximum detached ADU size to the minimum livable floor area of your zone, which can land below the 1,200 sq ft headline number on some lots.
Ask about ADU Express if you want a faster review. Eligible projects can move through plan check much faster than a standard application, though eligibility screening itself can take a few weeks.
Budget extra time beyond the 60-day statutory clock. Real-world review commonly runs 10-14 weeks once resubmittals are factored in, so build that into your construction schedule.
If your property recently went through a lot split or two-unit development approval, check ADU eligibility carefully. This is an area the state flagged for a local compliance fix in 2025, so confirm the current rule with Anaheim Planning.
Keep new construction at or under 750 sq ft if avoiding impact fees matters to you. Crossing that threshold can trigger proportional local impact fees and, above 500 sq ft, school fees.
FAQ
Common questions
Do I need to live on the property to build an ADU in Anaheim?
No. California law (AB 976, effective January 1, 2024) permanently bars cities from requiring owner-occupancy for standard ADUs. A Junior ADU still requires owner-occupancy if it shares sanitation facilities with the primary home.
How many ADUs can I build on one lot in Anaheim?
A single-family lot can generally add one ADU plus one JADU in addition to the primary home. Multifamily properties can add up to 8 detached ADUs plus interior conversions of up to 25% of existing units. Exact stacking depends on your lot - confirm with Anaheim Planning.
Do I need extra parking for an ADU?
Only sometimes. Studio ADUs and JADUs need no parking. A one-bedroom-or-larger ADU needs 1 space, but that requirement is waived entirely if you're within a half mile of a transit stop or meet other state-listed exemptions.
How long does the permit process take?
The city must issue a completeness determination within 15 business days and a final decision within 60 days of a complete application. In practice, local reporting suggests full review often runs closer to 10-14 weeks once resubmittals are factored in.
What's the maximum size for a detached ADU in Anaheim?
Up to 1,200 sq ft, but Anaheim also caps detached accessory structures at the underlying zone's minimum livable floor area (roughly 1,700 sq ft in the RH zones or 1,225 sq ft in the RS-2 through RS-4 zones) and the ADU can't exceed the primary dwelling's own square footage. State law guarantees at least an 800 sq ft ADU regardless.
How much does an ADU cost to build in Anaheim?
Garage conversions tend to run roughly $70,000-$180,000, basement conversions (less common in California) roughly $100,000-$220,000, and new detached units $150,000-$350,000 or more, based on local contractor estimates and regional reporting. City permit fees are reported at roughly $3,500-$12,000 on top of construction cost.
Can I sell my ADU separately from my house?
In some cases, yes. Statewide AB 1033 allows an ADU to be sold as a separate condominium unit if a city opts in, and regional reporting identifies Anaheim as the most active jurisdiction in Orange County for this program. Confirm current eligibility and process with the city.
Are there fees specifically for ADUs in Anaheim?
ADUs of 750 sq ft or less are exempt from most local impact fees under state law. Larger ADUs may owe proportional impact fees, and school fees can apply above 500 sq ft of livable area. City permit fees are reported at roughly $3,500-$12,000 depending on project scope.
Can I add multiple ADUs if I own a multifamily property in Anaheim?
Yes. Under statewide SB 1211 (2024), owners of existing multifamily properties can add up to 8 detached ADUs on one lot, plus interior conversions of up to 25% of existing units, subject to Anaheim's standards.
