ADU Rules in Anaheim (2026): What You Can Build

An accessory dwelling unit (ADU) is a second, self-contained home on a residential lot with its own kitchen, bathroom and entrance. Anaheim permits ADUs and junior ADUs under California state law (Government Code 66310–66342) and its own ordinance, Anaheim Municipal Code Section 18.38.015, which allows a detached ADU of up to 1,200 sq ft on a single-family lot. Green Design and Build is a licensed general contractor (CSLB #1110975) serving homeowners across Los Angeles County, Orange County, Ventura County, western Riverside County and western San Bernardino County; this page sets out what Anaheim lets you build and how its process runs.

Who we are

Green Design and Build is led by Dekel Sofer; we have completed hundreds of projects and hold a 4.7-star rating across 146 Yelp reviews. We are a full-service residential general contractor and design-build remodeler, not an ADU specialist: ADUs and garage conversions are one part of what we build alongside kitchens, bathrooms, additions and whole-home renovations, as our Anaheim page shows.

ADU rules in Anaheim at a glance

Rule	Anaheim (AMC 18.38.015 and 18.42.030, amended January 2026)
Detached ADU, max size	1,200 sq ft
Attached ADU, max size	50% of the main house or 1,200 sq ft, whichever is less; never less than 850 sq ft (studio or one-bedroom) or 1,000 sq ft (two-plus bedrooms)
Minimum size	150 sq ft
Junior ADU (JADU)	Up to 500 sq ft inside the walls of the house; owner-occupancy required if it shares a bathroom with the house
Height, detached	18 ft plus 2 ft for a pitched roof, or the height of the main house, whichever is greater (state floor: 16 ft; 18 ft near transit)
Height, attached	Underlying zone; the city may not impose less than 25 ft or the main house’s limit, whichever is lower
Setbacks	4 ft side and rear; no closer to the street than the front wall of the house (garage conversions excepted); 10 ft from the main house; conversions exempt from setbacks, height, lot coverage and separation
Parking	Studio: none. One or more bedrooms: 1 space, waived within a half-mile walk of transit, in a historic district, for conversions, for JADUs, and when a garage is demolished or converted. No replacement parking for a converted garage
Owner-occupancy	Not required for an ADU (state law); required for a JADU sharing sanitation with the house, by recorded covenant
Units on a single-family lot	One ADU converted from existing space, one new-construction ADU and one JADU; four units maximum including the house
Short-term rental	Not allowed; 30 consecutive days minimum
Impact fees	None under 750 sq ft; proportional above
Review timeline	15 business days to confirm completeness, then 60 days to approve or deny, ministerially
Where to apply	Planning and Building Department, City Hall, 200 S. Anaheim Blvd., Suite 162, Anaheim, CA 92805, (714) 765-5139; plans, fees and inspections through the Anaheim NEXT portal (Anaheim.net/Next)

Size, height and setbacks

The 1,200 sq ft detached limit matches the ceiling state law sets, and state law also guarantees that a new ADU of at least 800 sq ft with 4 ft side and rear setbacks cannot be blocked by lot coverage, floor-area ratio, open-space or front-setback rules, which matters on the 6,000–7,500 sq ft tract lots that make up most of Anaheim. Anaheim’s detached height limit is more generous than the 16 ft state minimum: 18 ft, plus 2 ft for a pitched roof, or as tall as the main house if the house is taller, enough for a two-story unit over a garage. Setbacks are the state-standard 4 ft, with two local placement rules: a detached ADU cannot sit closer to the street than the front wall of the house (a converted garage is the exception) and must keep 10 ft from the main house.

Three local twists shape the design. In the Anaheim Colony Historic District, an ADU on a lot with a National or California Register listing or a Mills Act contract must match character-defining features such as cladding, roof form, windows, porches and door types, and Mills Act properties must meet the Secretary of the Interior’s Standards. In Anaheim Hills, HOA architectural review comes before the city, though Civil Code 4751 voids any HOA rule that effectively prohibits or unreasonably restricts an ADU; the slopes add engineered foundations, and lots in the Very High Fire Hazard Severity Zones east of the 55 build to Chapter 7A with Class A roofing. Citywide, the ordinance lets the City Council exclude areas with insufficient sewer capacity, which is why a sewer deficiency verification from Public Works is the first item on the submittal checklist.

Garage conversions and JADUs in Anaheim

A garage conversion is the simplest ADU in Anaheim: conversions of legally permitted structures are exempt from setbacks, height, lot coverage and building separation, and the footprint may grow by up to 150 sq ft solely for ingress and egress. No replacement parking is required when the garage is converted or demolished, and the converted unit needs none of its own. Fire sprinklers are not required if the main house does not require them, which covers most of Anaheim’s 1950s–60s ranch houses, and state law bars the city from requiring a separate utility connection for a conversion. See our garage conversion page for the construction side.

A junior ADU is a unit of no more than 500 sq ft inside the walls of the house, with its own outside entrance and an efficiency kitchen. It may share a bathroom with the house, and when it does, the owner must live in either the house or the JADU; Anaheim records that as a covenant drafted by the City Attorney and recorded with the Orange County Clerk-Recorder before the permit issues, and asks for a recent title report and the grant deed with the application. A lot can have a JADU and an ADU at the same time, up to the four-unit cap.

Pre-approved plans, fees and utilities

Anaheim runs an ADU Express program with a free Pre-Approved Plan Catalogue: Plan 001, a 224 sq ft studio; Plan 002, a 499 sq ft one-bed, one-bath; Plan 003, a 990 sq ft two-bed, two-bath; and Plan 004, a 1,199 sq ft three-bed, three-bath, all drawn to the building code in effect since July 1, 2024. Eligibility is address-based, checked through the city’s online lookup tool. If the lot qualifies, staff meet with you to produce the site plan and take the upload, and once school and impact fees are paid the city says the permit can issue within a day; the screening before that meeting can take a few weeks. Custom designs go through the standard process. (The City of Los Angeles runs a similar, much larger Standard Plan Program.)

Fee amounts depend on unit size and address, so confirm them with the city. The categories are plan check and building permit fees; development impact fees, waived under 750 sq ft and prorated above; school district developer fees on ADUs larger than 500 sq ft (six districts serve parts of Anaheim); a new-address application; and any utility connection or capacity charges, which state law requires to be proportionate to the ADU’s burden.

Utilities are where Anaheim differs from most of Orange County: electricity and water come from Anaheim Public Utilities (APU), the city-owned utility, not Southern California Edison. Any ADU that adds, upgrades or relocates an electric meter needs an APU meter spot report first, requested at Anaheim.net/3472 or (714) 765-6847 and usually returned in two to three business days; APU’s ADU Express instructions ask for a 400-amp multi-meter location. Separate metering is allowed but not required for a conversion.

The permit process in Anaheim, step by step

1. Confirm the address. Colony Historic District and Mills Act status, Anaheim Hills HOA, fire hazard zone, and ADU Express eligibility.
2. Pre-submittal items. Sewer deficiency verification from Public Works (PWPermits@anaheim.net, up to four days), the APU meter spot, and a new address from Business Assistance at 200 S. Anaheim Blvd., Suite 162 (by 11 AM for same-day processing).
3. Design and engineering. Site plan, floor plans and elevations, structural calculations, Title 24 energy compliance; soils work in Anaheim Hills; historic conformance in the Colony.
4. Submit through Anaheim NEXT. The Planning and Building Department has 15 business days to confirm completeness and then 60 days to approve or deny, with no hearing and no discretionary conditions.
5. Plan check corrections from Planning, Building, Public Works and Fire, answered and resubmitted until the set is clean.
6. Fees and permit. School fees go to the district first; impact fees, if any, at issuance; JADU covenants are recorded before release.
7. Construction and inspections through final, scheduled through Anaheim.net/Next; APU sets the meter.
8. Certificate of occupancy, after which the unit can be occupied or rented for 30 days or longer.

Design, permitting and construction together typically run six months to a year in Anaheim; the 60-day clock starts only once the application is complete, and the pre-submittal items and correction rounds sit outside it.

What an ADU costs in Anaheim

Our published Los Angeles-area budgeting ranges apply in Anaheim, and they are ranges, not a quote:

ADU type	Typical all-in budget
Garage conversion ADU	$100,000–$200,000
Detached ADU, about 500 sq ft	$180,000–$260,000
Detached ADU, 700–800 sq ft	$225,000–$350,000
Detached ADU, 1,000 sq ft	$300,000–$450,000+
Rule of thumb	$300–$450 per sq ft all-in; $500+ per sq ft on difficult lots

The Anaheim-specific drivers are an APU service upgrade or multi-meter panel, an Anaheim Hills lot needing a soils report, engineered footings and Chapter 7A exterior materials, and historic design conformance in the Colony. Flat tract lots sit at the low end of each range. Our guides on how much it costs to build an ADU and why ADU quotes vary so much between contractors walk through a real budget line by line.

Frequently asked questions

How big of an ADU can I build in Anaheim?

Anaheim allows a detached ADU of up to 1,200 sq ft on a single-family lot. An attached ADU is limited to 50% of the main house or 1,200 sq ft, whichever is less, but never less than 850 sq ft for a studio or one-bedroom or 1,000 sq ft for two or more bedrooms. A junior ADU inside the house is capped at 500 sq ft.

How tall can a detached ADU be in Anaheim?

Anaheim allows a detached ADU up to 18 feet, plus 2 feet for a pitched roof, or the height of the main house if that is taller. That is above the 16-foot minimum state law requires and is enough for a two-story unit or an ADU above a garage. Attached ADUs follow the height limit of the underlying zone.

Does an ADU in Anaheim need a parking space?

An Anaheim ADU with one or more bedrooms needs one parking space unless an exemption applies; a studio needs none. The exemptions cover most lots: within a half-mile walk of transit, in a historic district, any conversion, any JADU, and any project where a garage is demolished or converted. Replacement parking for a converted garage is never required.

Do I have to live on the property to build an ADU in Anaheim?

No. Anaheim does not impose an owner-occupancy requirement on ADUs, and state law prohibits cities from doing so. The exception is a junior ADU that shares a bathroom with the main house, which requires the owner to live in either the house or the JADU under a covenant recorded before the permit is issued.

How long does it take to get an ADU permit in Anaheim?

Anaheim has 15 business days to confirm an ADU application is complete and then 60 days to approve or deny it, with no public hearing. Pre-submittal items and plan check corrections add time outside that clock, and ADU Express projects on a pre-approved plan move faster. Design, permitting and construction together usually take six months to a year.

Does Anaheim have pre-approved ADU plans?

Yes. Anaheim’s ADU Express program offers a free Pre-Approved Plan Catalogue with four plans: a 224 sq ft studio, a 499 sq ft one-bedroom, a 990 sq ft two-bedroom and a 1,199 sq ft three-bedroom. Eligibility is address-based and checked through the city’s online lookup tool, and the city says a permit can issue within a day once the site plan is done and fees are paid.

Ready to see what fits on your Anaheim lot?

Run your address through our [ADU rules calculator](/adu-rules-calculator/) for the state-law floor, then let us confirm the Anaheim specifics, the APU meter, the sewer check and any Colony or Anaheim Hills review, on a free site visit. We build [ADUs](/adu/) throughout [Orange County](/service-areas/orange-county/), and our [ADU rules by city](/adu-rules/) hub covers the neighboring jurisdictions.