In Anaheim, a detached ADU can be up to 1,200 square feet and 18 feet tall (plus 2 feet for roof pitch), with 4-foot side and rear setbacks. A detached ADU over 800 square feet has to be 10 feet from the main house. Studio ADUs need no parking, and ADUs with a bedroom need one space unless a state exemption applies. Those standards are in Anaheim Municipal Code § 18.38.015.
Anaheim is Orange County’s second-busiest ADU city. It finaled 226 ADUs in 2025 and 866 since 2005, behind only Garden Grove, according to Cal State Fullerton’s ADU report. That volume means good comps and builders who know plan check. It also means a lot of older back units with permit questions. Here’s what I check before an Anaheim buyer writes an offer.
Anaheim ADU Rules at a Glance
| Rule | What Anaheim allows |
|---|---|
| Units on a single-family lot | Up to 4 total: main home, 1 conversion ADU, 1 detached ADU and 1 JADU |
| Units on a multifamily lot | Conversions up to 25% of existing units (min. 1), plus up to 8 detached ADUs, never more than existing units |
| Detached ADU size | Up to 1,200 sq ft |
| Attached ADU size | State minimum of 850 sq ft (1,000 with 2+ bedrooms), or 50% of the home |
| JADU size | Up to 500 sq ft |
| Detached height | 18 ft + 2 ft for roof pitch, or the main home’s height if taller |
| Side and rear setbacks | 4 ft; none for conversions |
| Front setback | No closer than the main home’s front wall; garage conversions can stay put |
| Separation from main home | 10 ft, only for detached ADUs over 800 sq ft |
| Parking | 0 for studios, 1 for 1+ bedroom ADUs, 0 for JADUs; no replacement for converted garages |
| Impact fees | None at 750 sq ft or less |
| Approval | Ministerial building permit, decided within 60 days of a complete application |
Confirm with Anaheim Planning before you buy. The state rules every city must follow are on the California HCD ADU page.
The 10-Foot Separation Rule
This is the Anaheim rule that kills the most backyard plans. A detached ADU over 800 square feet must sit 10 feet from the main house. At 800 square feet or less, the state minimums apply instead. On a shallow lot, that 10 feet can be the difference between a 2-bed and a 1-bed.
I walk through real lot layouts in Anaheim ADU Permits: The 10-Foot Separation Rule Explained.
Anaheim-Specific Checks Buyers Miss
- Sewer capacity. Anaheim requires written sewer-capacity verification before plan check, and ADUs are prohibited where the City Council has found the sewer insufficient. Ask early.
- SB 9 plus ADU. You can’t add an ADU or JADU on a parcel that has permits for both an SB 9 two-unit development and an urban lot split. If you’re planning SB 9, read Anaheim’s SB 9 owner-occupancy covenant and the self-certification form first.
- Historic districts. Properties in Anaheim’s historic neighborhoods have to follow the city’s architectural style guide.
- Permit history. In my October report, several listings showed “unknown” permits for some rooms or units. Pull the permit file before you remove contingencies. An unpermitted unit gets little or no value at appraisal, as I explain in How an Unpermitted ADU Gets Treated at Appraisal. My escrow checklist is in How to Verify ADU Potential While You’re in Escrow.
What Anaheim ADU Homes Cost and Rent For
From my October 2026 Anaheim ADU report:
| Data point | Anaheim, October 2026 |
|---|---|
| ADU homes for sale | 8 |
| Asking price range | $968,000 to $1,840,000 |
| Median asking price | About $1,449,500 |
| Median days on market | About 49 |
| Homes with a price cut | 4 of 9 still being marketed |
| 2-bed ADU rents on current listings | $2,800 to $3,450 |
Homes are sitting about two months, so buyers have more room to negotiate than they’ve had in a while. Anaheim ranks third on my list of the best cities to buy a home and add an ADU, behind Garden Grove and Lakewood.
The Payment Math on an Anaheim ADU Home
I compare the total monthly payment (principal, interest, taxes and insurance) with total rent.
Example: 1641 W Buena Vista, listed at $1,475,000 with an 800 square foot ADU already renting for $3,450. I used $1,450,000 as a negotiated price and estimated the main house at about $4,500 a month. Rate is 7.75% for an investment loan, taxes at about 1.15%, and $200 a month for insurance.
| 25% down ($362,500) | 50% down ($725,000) | |
|---|---|---|
| Monthly payment (PITI) | About $9,380 | About $6,780 |
| Total rent | About $7,950 | About $7,950 |
| Monthly difference | About -$1,430 | About +$1,170 |
At 25% down it’s a hold for appreciation. At 50% down it cash flows. If you live in the main house and rent the ADU, your out-of-pocket cost drops to about $5,900 a month at 25% down. I show the house-hacking side in How Much of the Mortgage Does ADU Rent Cover?
Frequently Asked Questions
How big can an ADU be in Anaheim?
Up to 1,200 square feet detached. A JADU can be up to 500 square feet.
Does Anaheim require parking for an ADU?
Studios need none. ADUs with one or more bedrooms need one space, unless the property is within half a mile of transit or meets another state exemption. Converting a garage never requires replacement parking.
What is Anaheim’s 10-foot rule?
A detached ADU over 800 square feet must be 10 feet from the main house. ADUs of 800 square feet or less and conversions are exempt.
How many ADUs can I build in Anaheim?
On a single-family lot, one conversion ADU, one detached ADU and one JADU, for up to four homes total. AB 956 adds a second detached ADU option starting January 1, 2027.
What does an ADU rent for in Anaheim?
Two-bed ADUs on current Anaheim listings rent for $2,800 to $3,450 a month.
Tour Anaheim Homes With Real ADU Potential
I’ll show you which Anaheim homes clear the separation rule and the sewer check, with projected rents and build costs for each one, before you write an offer.
👉 Book a buyer ADU consult call to go through your options with Dylan
Prefer to talk now? Call Dylan Serna, ADU Realtor at 714-860-2868.
Dylan Serna | The ADU Realtor | eXp Realty | DRE #02217359
This post is general information, not legal, tax or financial advice. Rents and payments are estimates; confirm rules for any specific property with the city.
