BackyardADU

Building an ADU in Huntington Beach: 2026 cost & rules guide

Huntington Beach permitted 210 ADUs from 2013 to 2022 — among the most active markets in California. Here's what it costs, what's allowed, and who builds them.

Region: Los Angeles Last updated April 2026
Lifetime permits 2013–22
210
Permits in 2022
91
from 0 to 91
Peak year
2022
91 permits
Typical cost range
$72,000–$375,000

How much an ADU costs in Huntington Beach

All-in design-build estimates (architecture + permits + construction + soft costs). Real quotes vary by lot conditions, finishes and contractor — get at least three before signing.

Detached ADU

$225,000–$375,000
$300–$500 per sqft · ~750 sqft typical

Attached ADU

$189,000–$308,000
$270–$440 per sqft · ~700 sqft typical

Garage Conversion

$72,000–$132,000
$180–$330 per sqft · ~400 sqft typical

Junior ADU (JADU)

$64,000–$120,000
$160–$300 per sqft · ~400 sqft typical

Prefab ADU

$150,000–$240,000
$250–$400 per sqft · ~600 sqft typical

Basement Conversion

$120,000–$228,000
$200–$380 per sqft · ~600 sqft typical

Per-square-foot ranges reflect 2026 pricing in the los angeles market. Permit fees ($5–25k), site work ($10–40k) and high-end finishes can push totals 20–40% higher.

Huntington Beach ADU rules & zoning

California state law sets a floor that every city must meet. Huntington Beach may allow more than the minimums shown — confirm with the Huntington Beach planning department before finalising plans.

RuleStandard
ADUs allowed on single-family lotYes — required by state law
Max units per lot1 ADU + 1 JADU on single-family; up to 2 detached ADUs + JADU on multifamily
Owner-occupancy requiredNot allowed to require for ADUs (state preempts)
Min side & rear setback (detached)4 feet
Max height (detached, single-family lot)16 ft — 18 ft if within 0.5 mi of major transit
Off-street parkingNone required if within 0.5 mi of public transit (state law applies in most metros)
Max ADU size (detached)850 sqft for studio/1BR; 1,000 sqft for 2+BR (city may allow more)
Min lot sizeNo minimum required by state
Permit timeline (ministerial)60 days from complete application (state law)

ADU permit history in Huntington Beach

Annual ADU permits issued, 2013–2022. Source: Big West Coast ADU Dataset (BuildinganADU.com).

28
31
60
91
2019202020212022

ADU specialist builders in Huntington Beach

Active CA-licensed B-class general contractors with ADU-specialist branding, sourced from the CSLB Public Data Portal. Always verify license status and read recent reviews before signing.

Custom Modular Services Corporation

19271 Fiji Lane, Huntington Beach 92646
(714) 964 6834
CSLB #570805 · B · licensed 06/14/1989

Frequently asked questions

How much does an ADU cost in Huntington Beach?

Most Huntington Beach ADU projects fall in a $150,000–$400,000+ range, all-in (design + permits + construction). The big drivers are size, type (detached costs more than a garage conversion), and finish level. See the per-type cost table above for typical ranges in this market.

Do I need a permit to build an ADU in Huntington Beach?

Yes — every ADU in California requires a building permit. Huntington Beach processes ADU applications under the state's 60-day ministerial review rule (no public hearings, no discretionary review for code-compliant designs). Permit fees vary but typically run $5,000–$25,000 depending on size and impact fees.

Can my ADU in Huntington Beach be larger than 1,000 sqft?

State law guarantees a minimum allowance of 850 sqft (studio/1BR) or 1,000 sqft (2+BR). Many California cities allow larger detached ADUs — check the Huntington Beach planning department or the ordinance link in our rules table above for the local maximum.

Do I need to live on the property to build an ADU in Huntington Beach?

No. State law prohibits California cities from requiring owner-occupancy on ADUs permitted between 2020 and 2025. From 2025 onward, cities may reinstate owner-occupancy requirements — verify with your planning department before committing.

What's the difference between an ADU and a JADU?

A JADU (Junior ADU) is a unit ≤500 sqft created within an existing single-family home, sharing a wall with the main residence. JADUs are cheaper and faster to build, but they require owner-occupancy of either the main house or the JADU. Most homeowners build a separate ADU for rental flexibility.

How many ADUs are being built in Huntington Beach?

According to the California ADU permit dataset compiled by BuildinganADU.com, Huntington Beach permitted 91 ADUs in 2022, the peak year on record (2013–2022). California-wide ADU permits have grown roughly 20× over that period — homeowner demand is outpacing every other housing-supply tool the state has tried.