BackyardADU

Building an ADU in Garden Grove: 2026 cost & rules guide

Garden Grove permitted 2,203 ADUs from 2013 to 2024 — among the most active markets in California. Here's what it costs, what's allowed, and who builds them.

Ordinance grade: C Region: Los Angeles Permit data through 2024 (+ 2025 YTD) Last updated May 2026
Lifetime permits 2013–2024
2,203
Permits in 2024
426
+142× since 2013
Peak year
2024
426 permits
Typical cost range
$36,000–$360,000

How much an ADU costs in Garden Grove

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

$135,000–$360,000
$180–$480 per sqft · ~750 sqft typical

Attached ADU

$105,000–$266,000
$150–$380 per sqft · ~700 sqft typical

Garage Conversion

$36,000–$96,000
$90–$240 per sqft · ~400 sqft typical

Junior ADU (JADU)

$36,000–$96,000
$90–$240 per sqft · ~400 sqft typical

Prefab ADU

$81,000–$216,000
$135–$360 per sqft · ~600 sqft typical

Basement Conversion

$63,000–$168,000
$105–$280 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. See cost methodology for the full regression model and the 8 California builder-pricing sources it's calibrated against.

Garden Grove ADU rules & zoning

California state law sets a floor that every city must meet. Garden Grove may allow more than the minimums shown — confirm with the Garden Grove planning department before finalising plans. See how we verify city-specific ordinance data.

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)
Side setback (detached) — local4 (state minimum; certain zones require 5)
Rear setback (detached) — local4 (state minimum)
Max height — local16 ft
Off-street parking — localNone required if within 0.5 mi of public transit (state law applies in most metros)
Max ADU size — local850 (studio/1BR), 1200 (2+BR per municipal code)
Min lot sizeNo minimum required by state
Permit timeline (ministerial)60 days from complete application (state law)

Garden Grove-specific rules

  • ADU Go: pre-approved plans programme reduces design fees
  • ADUs governed by Garden Grove Municipal Code Chapter 9.54
  • Owner-occupancy required for JADUs (state-mandated, not local)
  • Design guidelines apply to ensure compatibility with primary residence

Source: Garden Grove planning department. Verified April 2026.

ADU permit history in Garden Grove

Annual ADU permits issued, 2013–2025. Sources: Big West Coast ADU Dataset for 2013–2022 and the California HCD Annual Progress Report (April 2026 snapshot) for 2023–2025.

3
5
7
6
13
82
96
379
407
374
405
426
434*
2013201420152016201720182019202020212022202320242025*

*Partial year. HCD's 2025 APR snapshot (April 2026) reflects jurisdictions that filed by the April 1 deadline; remaining cities continue to report through mid-2026.

ADU specialist builders in Garden Grove

Active CA-licensed B-class general contractors with ADU-specialist branding, sourced from the CSLB Public Data Portal snapshot from April 28, 2026. Click any license number to verify current status at the CSLB Instant License Check — status can change at any time. See builder-directory methodology.

Advanced Modular Construction

11981 Bartlett St, Garden Grove 92845
(714) 225 8879
CSLB #964478 · B · first licensed 08/12/2011

Frequently asked questions

How much does an ADU cost in Garden Grove?

Most Garden Grove ADU projects fall in a $100,000–$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 Garden Grove?

Yes — every ADU in California requires a building permit. Garden Grove 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 Garden Grove 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 Garden Grove 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 Garden Grove?

No, not for an ADU. AB-976 (effective 2023) extended the state's ban on owner-occupancy requirements for ADUs through January 1, 2030 — California cities may not require an owner to live on the property as a condition of permitting an ADU during that window. JADUs are different: owner-occupancy of either the primary residence or the JADU itself is required by state law throughout the JADU's life.

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 Garden Grove?

According to the California ADU permit dataset compiled by BuildinganADU.com, Garden Grove permitted 426 ADUs in 2024, 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.

How did Garden Grove's ADU ordinance compare to other cities in 2020?

UC Berkeley's Center for Community Innovation graded Garden Grove's ordinance C in their 2020 ADU Scorecard, scoring the 2017 ordinance text. The mean grade across California was C+, so anything above that ranked as relatively homeowner-friendly at the time. This is historical, not current law: state-level updates since 2020 (AB-2221, AB-976, AB-1033, SB-477, SB-1211 and others) have raised the statewide floor and many cities have rewritten their local ordinances since the 2020 grading. Always check the current ordinance text linked above for what applies to a project you're about to start.