Everything homeowners ask about building an ADU in Anaheim — answered with 2026 data.
Yes, ADUs are allowed in Our zone list is incomplete — it omits the three RH hillside zones and RM-3.5. The code permits ADUs and JADUs in all areas zoned to allow single-family or multiple-family residential use. Single-family zones: RH-1, RH-2, RH-3, RS-1, RS-2, RS-3, RS-4. Multiple-family zones: RM-1, RM-2, RM-3, RM-3.5, RM-4. Two absolute local exclusions we do not mention at all: no ADU or JADU on any parcel that has obtained a permit for an SB 9 Two-Unit Development or Urban Lot Split, and none in any area the City Council designates by resolution as having insufficient sewer infrastructure. in Anaheim, CA. The maximum size for a detached ADU is 1,200 sq ft headline cap, but expressly 'subject to 18.04.080.020', which caps the cumulative floor area of ALL enclosed detached accessory structures at the underlying zone's minimum livable floor area (1,700 sq ft in RH-1, RH-2, RH-3 and RS-1; 1,225 sq ft in RS-2, RS-3, RS-4) and further provides it 'shall not exceed the square footage of the main dwelling'. So on a modest primary home the detached ADU is limited to the size of that home. State law still guarantees at least 800 sq ft regardless.. Attached ADUs can be up to The LESSER of 50% of the main dwelling or 1,200 sq ft — but never reduced below 850 sq ft for a studio or one-bedroom unit, or 1,000 sq ft for a unit with two or more bedrooms. Our current wording omits both 'whichever is less' and the 850/1,000 sq ft floor, so it reads as more generous than the code for large houses and stricter than the code for small ones.. Anaheim has an ADU-friendliness score of 7/10. Check our full Anaheim ADU rules page for complete zoning details.
ADU construction in Anaheim typically costs $130,000-$290,000. The cost per square foot averages $195-$350. Garage conversions are more affordable at $75,000-$165,000, while prefab ADUs cost $100,000-$235,000. Permit fees add $3,500-$12,000 to your budget. See our detailed Anaheim ADU cost guide.
Detached ADUs in Anaheim can be up to 1,200 sq ft headline cap, but expressly 'subject to 18.04.080.020', which caps the cumulative floor area of ALL enclosed detached accessory structures at the underlying zone's minimum livable floor area. Attached ADUs are limited to The LESSER of 50% of the main dwelling or 1,200 sq ft — but never reduced below 850 sq ft for a studio or one-bedroom unit, or 1,000 sq ft for a unit with two or more bedrooms. Our current wording omits both 'whichever is less' and the 850/1,000 sq ft floor, so it reads as more generous than the code for large houses and stricter than the code for small ones.. Junior ADUs (JADUs) have a cap of 500 sq ft (unchanged, and correct). Minimum unit size 150 sq ft. Up to 150 sq ft may be added to an existing main dwelling to accommodate ingress or egress, but the overall unit must still not exceed 500 sq ft. Anaheim adopts the state maximum exactly.. Maximum height is MORE GENEROUS than state law and our current value is wrong. Detached ADU, on any residential lot: 18 ft plus an additional 2 ft for a roof pitch, or the height of the main dwelling unit, whichever is GREATER. This applies to both the sub-800 sq ft and over-800 sq ft categories and is not conditioned on transit proximity or a multifamily lot. Attached ADUs and JADUs: the height standards of the underlying zone. On a multifamily lot, detached ADUs are likewise 18 ft plus 2 ft for roof pitch.. You are allowed up to MORE GENEROUS than we state. On a single-family zoned lot Anaheim allows, in combination: one ADU within the existing or proposed space of the house or an accessory structure on a qualifying lot.
Rear setback: 4 ft (unchanged, and correct — Anaheim adopts the state minimum verbatim in Table 38-A). Worth adding: conversions of legally permitted existing structures are exempt from structural setbacks entirely, and a legally established accessory structure may be demolished and rebuilt as an ADU in the same location and dimension without additional setbacks. Eaves/roof overhang must stay at least 12 inches from the property line.. Side setback: 4 ft (unchanged, and correct — Anaheim adopts the state minimum). Same conversion exemption and 12-inch eave rule as the rear setback.. Front setback: Underlying zone, PLUS a local placement rule our page omits: a detached ADU may be no closer to the front property line than the front-most building wall of the main dwelling, except where the ADU results from converting an existing garage, carport or covered parking structure. An attached ADU above an existing nonconforming structure in the front setback is exempt if it keeps the same location and dimension. The Planning and Building Director may permit a modified front setback where the standard would prevent creation of an 800 sq ft unit — a built-in safety valve that is probably what keeps this rule from being preempted.. Note that garage conversions may be exempt from setback requirements if the existing structure is already within the setback area.
Substantively right but the CITATION IS WRONG — this comes from AMC 18.42.030.070, not 18.38.015 (which merely cross-references it). Studio ADU: 0 spaces. ADU with one or more bedrooms: 1 space. JADU: 0, always. Parking is waived entirely where the ADU is within a half-mile walking distance of a transit stop, in an architecturally and historically significant historic district, part of the existing/proposed primary residence or an existing accessory structure, where on-street parking permits are required but not offered to the occupant, where a car-share station is within one block, or where a garage/carport is demolished or converted for the ADU. No replacement parking is ever required for a demolished or converted garage. Any required space must be exclusive to the ADU if shared in the main garage.. Many cities and states have been relaxing ADU parking requirements in recent years. In California, no additional parking is required for ADUs near transit.
Our JADU half is incomplete and currently misleads. No owner-occupancy requirement for an ADU. For a JADU, owner-occupancy applies ONLY where the JADU SHARES sanitation facilities with the primary residence — a JADU with its own bathroom carries no owner-occupancy requirement at all. Where it does apply: a covenant must be recorded with the Orange County Recorder before the building permit issues, the unit not occupied by the owner may only be rented for 30 or more consecutive days, and the requirement is waived where the owner is a governmental agency, land trust or housing organization. Anaheim tracks Gov. Code 66333(b)/AB 1154 exactly.. Note that owner-occupancy rules vary by state law — California and several other states have eliminated this requirement for standard ADUs.
The ADU permit review timeline in Anaheim is typically '60 days' alone is incomplete. The code sets a two-stage clock: the city must determine whether the application is complete within 15 BUSINESS days, and every resubmittal is subject to the same 15-business-day review period; once deemed complete, the permit must be approved or denied within 60 days. Where the ADU application is filed together with an application for a new primary dwelling, the city may defer the ADU decision until the primary is decided. Separately, via ADU Express the city advertises the review completed in 1-3 days with the building permit issued in as little as one day — but be honest that the city also says the eligibility screening beforehand 'can take a few weeks to complete'.. Plan check: Standard city review. Pre-approved plans availability: Badly understated — this is the most commercially valuable fact on the page. Anaheim publishes a Pre-Approved Plan Catalogue of four detached ADU plans, each listed 'Free': Plan 001 studio, 224 sq ft; Plan 002 one bedroom / one bathroom, 499 sq ft; Plan 003 two bedroom / two bathroom, 990 sq ft; Plan 004 three bedroom / three bathroom, 1,199 sq ft. Plans include Building Code requirements effective 1 July 2024 and the city says it keeps adding plans. Two ways to use them: in the standard review process, or through ADU Express, an accelerated track for qualified single-family properties where the plans may NOT be modified. ADU Express steps include a free 400-amp multi-meter 'meter spot' from Anaheim Public Utilities (usually within three business days), an in-person site-plan meeting at City Hall, then payment of impact and school fees, after which the permit issues. Eligibility is checked by address through the city's ADU Express Eligibility Tool. Caveat to publish honestly: some catalogue plans still require the owner to hire a design professional for the site plan, Title 24, structural details and soils report..
Average ADU rental income in Anaheim: 1-bedroom units rent for $1,700-$2,300/month, 2-bedroom units for $2,000-$2,800/month. Short-term rentals: Strict STR regulations; limited to certain areas. Expected ROI: 7-10% annual return.
The minimum lot size for an ADU in Anaheim is No minimum (unchanged, and correct). I read the complete development standards table and Anaheim imposes no minimum lot size for an ADU or JADU. Worth adding what the table does say: lot coverage is expressly 'Not Applicable' to an ADU of 800 sq ft or less; for an ADU over 800 sq ft, and for a JADU, the underlying zone's lot coverage standards apply.. This applies to detached ADUs — garage conversions and JADUs may have different or no lot size requirements.
Garage conversions are one of the most popular and affordable ADU options. In Anaheim, a garage conversion typically costs $75,000-$165,000. The key advantages are lower cost (no foundation work), potential setback exemptions, and faster permitting. Read our complete garage conversion guide.
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