ADU Rules in Huntington Beach, California

Complete guide to building an Accessory Dwelling Unit in Huntington Beach — zoning, setbacks, permits, costs, and more.

Max Size: Up to 1,200 sq ft; 800 sq ft unit must be allowed on virtually any lot (state law) Setbacks: No more than 4 ft (state law); none for conversions of legally established existing space Parking: 1 Space Verified: 2026-07-10
ADU Score: 4/10
Restrictive · how we score

Huntington Beach's local ADU ordinance (HBZSO 230.10) is defunct — the city's own planning page confirms it reviews all ADUs and JADUs ministerially under state law, so California defaults apply (up to 1,200 sq ft, 16-ft height, 4-ft side/rear setbacks). Properties in the Coastal Zone may additionally need a Coastal Development Permit. The city has a contentious history: it halted ADU/SB 9 processing in February 2023, drew an HCD Notice of Potential Violation and a state lawsuit, and rescinded the ban on March 21, 2023; broader housing-law litigation continued through 2026. A free pre-approved 490 sq ft detached ADU plan (three architectural styles) is available under AB 1332.

Zoning & Size Requirements [1][2]

Yes — Huntington Beach allows ADUs. A detached ADU can typically be up to 1,200 sq ft under current California and Huntington Beach zoning rules.

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Allowed ZonesAll single-family and multifamily residential zones per state ADU law; local HBZSO Section 230.10 is no longer in effect per the city. Coastal Zone parcels may require a Coastal Development Permit
Max Size (Detached)Up to 1,200 sq ft; 800 sq ft unit must be allowed on virtually any lot (state law)
Max Size (Attached)50% of primary dwelling or 1,200 sq ft, whichever is less
Max Size (JADU)500 sq ft (within existing home or attached garage)
Max Height16 ft detached (18 ft within 1/2 mile of major transit or on multifamily lots, +2 ft roof pitch match); attached up to 25 ft or zone limit (state law)
Max UnitsSingle-family lot: 1 ADU + 1 JADU. Multifamily: 2 detached ADUs (up to 8 under SB 1211) + conversion ADUs up to 25% of existing units

Setback Requirements [1][2]

Huntington Beach requires a rear setback of about 4 ft for a detached ADU, and one off-street parking space is required. Owner-occupancy is not required — you can rent it out without living on the property.

Rear SetbackNo more than 4 ft (state law); none for conversions of legally established existing space
Side SetbackNo more than 4 ft (state law); none for conversions
Front SetbackUnderlying zone standard, but cannot preclude an 800 sq ft ADU
Parking RequiredMax 1 space; waived within 1/2 mile of transit and for conversions; no replacement parking required for garage conversions — relevant because much of HB is in the Coastal Zone
Owner OccupancyNot required for ADUs (AB 976). JADUs require owner occupancy unless the JADU has its own full bathroom (AB 1154, 2026)
Min Lot SizeNone under state law

Permit Process & Fees [3][4]

An ADU permit in Huntington Beach typically costs Building permits roughly $2,000-$10,000 plus other city fees of $3,000-$11,000 depending on project size (secondary-source estimates); a 6% automation fee is added — confirm with the HB Permit Center fee schedule and takes Initial plan review approximately 20 days, resubmittals 5-10 days; state law caps total ADU review at 60 days with deemed approval (SB 543, 2026), through a ministerial, by-right review.

Approval ProcessMinisterial building permit through the Permit Center (714-536-5271, permitcenter@surfcity-hb.org); no discretionary entitlement, but Coastal Zone properties may need a Coastal Development Permit — verify your parcel's coastal status with Planning first
Review TimelineInitial plan review approximately 20 days, resubmittals 5-10 days; state law caps total ADU review at 60 days with deemed approval (SB 543, 2026)
Permit FeesBuilding permits roughly $2,000-$10,000 plus other city fees of $3,000-$11,000 depending on project size (secondary-source estimates); a 6% automation fee is added — confirm with the HB Permit Center fee schedule
Impact FeesWaived for ADUs under 750 sq ft (state law); otherwise development impact fees are payable at permit issuance — confirm amounts with Community Development
Plan CheckPlan check via Permit Center; ~20-day first review, 5-10 days for rechecks — confirm current turnaround with the city
Pre-Approved PlansYes — free pre-approved 1-story, 490 sq ft detached ADU prototype in three styles (California Ranch, Bungalow, Spanish Colonial) under AB 1332; modifications to the pre-approved plan are not allowed

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Construction Costs [5][6]

Building an ADU in Huntington Beach typically costs $180,000-$420,000 ($315-$525 per sq ft); a garage conversion runs $90,000-$150,000.

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Average Build Cost$180,000-$420,000
Cost per Sq Ft$315-$525
Garage Conversion$90,000-$150,000
Prefab ADU (Installed)$120,000-$300,000

Finance Your ADU Project

Most ADU projects are funded through HELOCs, construction loans, or cash-out refinancing. Compare rates from top lenders.

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Rental Income Potential [7][8]

A 2-bedroom ADU in Huntington Beach rents for around $3,000-$3,300/mo, an estimated 5-8% annual return.

Avg Rent (1 Bedroom)$2,400-$2,700/mo
Avg Rent (2 Bedroom)$3,000-$3,300/mo
Short-Term RentalEffectively no for new ADUs — HB permits STRs under Chapter 5.120 (effective Feb 19, 2021), but ADUs/JADUs qualify only if legally established before that date
Est. Annual ROI5-8% annual return

Explore Prefab ADU Options

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Recent Law Changes

What's Changed Recently

  • Feb 2023: City Council voted to stop processing ADU and SB 9 applications; HCD issued a Notice of Potential Violation (Feb 21, 2023) and the state sued in March 2023
  • Mar 21, 2023: Council rescinded the ban and resumed ADU processing under state law
  • 2024-2026: State secured successive rulings in the housing-element litigation, including appellate orders and financial penalties; in July 2026 the AG defeated the city's countersuit against the state
  • AB 1332 pre-approved ADU program active: free 490 sq ft detached prototype plan in three architectural styles
  • Jan 1, 2026: SB 543 (60-day deemed approval) and AB 1154 (JADU owner-occupancy exception) took effect statewide

Tips for Building an ADU in Huntington Beach

  • Check whether your parcel is in the Coastal Zone before designing — a Coastal Development Permit can add months; ask Planning at (714) 536-5511
  • Use the free pre-approved 490 sq ft plan (Ranch, Bungalow, or Spanish Colonial) to skip architectural design fees and speed plan check — but no modifications are allowed
  • Keep the unit under 750 sq ft to avoid development impact fees, which HB collects at permit issuance
  • Budget for the 6% automation fee HB adds to all permit fees
  • New ADUs cannot be short-term rentals in HB — only units legally established before Feb 19, 2021 qualify for an STR permit; plan for 30+ day tenancies
  • If staff cite the old HBZSO 230.10 standards, note the city's own ADU page states that section is no longer in effect and state law governs

ADU Builders in Huntington Beach

Looking for an ADU builder in Huntington Beach? ADU projects need a contractor experienced with local zoning, the permit process, and utility connections — not every general contractor has built one. We match Huntington Beach homeowners with experienced local ADU contractors who provide free, no-obligation quotes. Getting at least three bids typically saves 20-40% on the same scope.

Sources & References

All data on this page is sourced from official government records and verified market data. View our full methodology.

  1. Accessory Dwelling Units (ADUs) — City of Huntington Beach city_website — Accessed 2026-07-10
  2. HCD Notice of Potential Violation — HB Intent to Cease Processing ADU Applications (Feb 21, 2023) state_statute — Accessed 2026-07-10
  3. Huntington Beach Pre-Approved ADU Program Brochure city_website — Accessed 2026-07-10
  4. Huntington Beach Building Permits — Review Times and Process (Permit Place) news_media — Accessed 2026-07-10
  5. Garage Conversion ADU Cost in Orange County — GatherADU news_media — Accessed 2026-07-10
  6. ADU Construction Cost in Orange County (2026) — Keystone news_media — Accessed 2026-07-10
  7. Average Rent in Huntington Beach, CA — RentCafe (July 2, 2026) news_media — Accessed 2026-07-10
  8. HB Municipal Code Chapter 5.120 — Short-Term Rentals Municipal Code — Accessed 2026-07-10

Frequently Asked Questions

Can I build an ADU in Huntington Beach?

Yes. ADUs are allowed in All single-family and multifamily residential zones per state ADU law; local HBZSO Section 230.10 is no longer in effect per the city. Coastal Zone parcels may require a Coastal Development Permit in Huntington Beach. The maximum size for a detached ADU is Up to 1,200 sq ft; 800 sq ft unit must be allowed on virtually any lot (state law). Owner-occupancy is not required, so you can rent out the ADU.

How much does an ADU cost in Huntington Beach?

ADU construction in Huntington Beach typically costs $180,000-$420,000. Garage conversions run $90,000-$150,000, and prefab ADUs cost $120,000-$300,000.

How much can I rent an ADU for in Huntington Beach?

Average ADU rents in Huntington Beach are $2,400-$2,700/mo for a 1-bedroom and $3,000-$3,300/mo for a 2-bedroom unit.

Do I need parking for an ADU in Huntington Beach?

Max 1 space; waived within 1/2 mile of transit and for conversions; no replacement parking required for garage conversions — relevant because much of HB is in the Coastal Zone. Check with Huntington Beach planning department for the latest California ADU parking rules, as many states have relaxed requirements in recent years.

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

The permit review timeline in Huntington Beach is Initial plan review approximately 20 days, resubmittals 5-10 days; state law caps total ADU review at 60 days with deemed approval (SB 543, 2026). Fees range from Building permits roughly $2,000-$10,000 plus other city fees of $3,000-$11,000 depending on project size (secondary-source estimates); a 6% automation fee is added — confirm with the HB Permit Center fee schedule.

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About this information: This page is an informational summary of publicly available regulations - it is not legal, financial, or professional advice, and it is not a substitute for confirming requirements with your local planning department. Rules change frequently; always verify current requirements before designing, budgeting, or building. Last verified: 2026-07-10. Contractors we introduce are independent businesses - verify license and insurance directly before hiring. Spotted an error? Tell us - we verify against primary sources and correct quickly.

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