Garden Grove Zoning and ADU Guide for Homeowners

Last updated November 13, 2026. Reviewed by the Cash Home Buyers CA team.

Garden Grove allows an accessory dwelling unit (ADU) and a junior ADU on most single-family lots, reviews them ministerially, and applies size, height and setback limits set in Chapter 9.54 of its municipal code. This guide summarizes the city’s published rules, explains how they affect a sale, and points to the offices that can confirm details for your lot.

Garden Grove ADU rules at a glance

Single-family lot	One ADU and/or one JADU
Multifamily lot	Up to 8 detached ADUs (not more than existing units), plus conversions up to 25% of existing units
Attached ADU max size	850 sq ft (studio or 1 bedroom), 1,200 sq ft (2+ bedrooms), or 50% of the primary home
Detached ADU max size	850 sq ft (studio or 1 bedroom), 1,200 sq ft (2+ bedrooms)
JADU max size	500 sq ft
Side and rear setbacks	4 feet
Detached height	16 feet (18 feet in some cases)
Review time	60 days for ministerial review
Planning contact	(714) 741-5312, planning@ggcity.org

What zoning means for your Garden Grove home

Zoning controls what you can build on a lot, how large and how tall it can be, and how close it can sit to the property line. Garden Grove’s ADU rules live in Chapter 9.54 of the municipal code, which follows California’s state ADU laws.

Under those laws the city must approve a compliant ADU through a ministerial process, meaning staff check the plans against objective standards rather than holding a discretionary hearing. The city’s ADU program page and a downloadable checklist and application, updated in 2024, walk applicants through what to submit.

Size and minimum size standards

The code sets both minimums and maximums. Minimum sizes are 150 square feet for an efficiency unit, 220 for a studio, 500 for a one bedroom and 700 for a two bedroom.

Attached ADUs are capped at 850 square feet for a studio or one bedroom and 1,200 for two or more bedrooms, or at 50 percent of the primary home, with the city allowing 800 square feet where the primary home is under 1,600 square feet. Detached ADUs follow the 850 and 1,200 square foot caps.

A converted ADU, built within existing space, has no maximum size. The code also permits a porch of up to 80 square feet and an attached garage of up to 250 square feet, with total ADU area not to exceed 1,530 square feet. A junior ADU is capped at 500 square feet.

Height, setbacks and placement

A detached ADU is generally limited to 16 feet in height. The limit rises to 18 feet for multifamily lots or lots near transit, with a further 2 feet allowed for roof pitch matching.

Attached ADUs can reach 25 feet or the height limit of the primary home, and no ADU can exceed two stories. Side and rear setbacks are 4 feet.

Conversions of existing structures need no additional setback, and front setbacks are waived for ADUs up to 800 square feet when that is the only way to build one. If an ADU has garage openings, the code asks for a 20 foot setback in front of them.

Parking requirements

A new ADU generally requires one parking space, with exemptions.

You do not need to provide it if the lot is within half a mile of public transit, in a historic district, if the ADU is a conversion of existing space, if permit parking is not offered to residents, or if a car share vehicle is within a block.

If you do not need the space, you also generally do not have to replace parking lost when a garage is converted, a rule that matters for older Garden Grove garage conversions.

Junior ADUs and owner occupancy

A junior ADU is a unit carved out of an existing single-family home, limited to 500 square feet. The city requires owner occupancy for a lot with a JADU, but not for a lot with a standard ADU. Either type can be rented, but not sold separately from the main house, and rentals must be for terms of 30 days or longer, which rules out short-term vacation rentals.

Review timeline and fees

The city must review a complete ADU application ministerially within 60 days, and within 30 days if you use a pre-approved plan. Impact fees are not charged for ADUs smaller than 750 square feet, and fees for larger units are charged in proportion to the size of the primary home. Once Planning signs off, the project goes through the plan check and inspection process explained in our Garden Grove building permits guide.

If your ADU or garage conversion was built without permits

Many older Garden Grove lots have converted garages, enclosed patios or backyard units that were never permitted. These can come to light through a complaint, a sale or a refinance.

The city’s code enforcement page says illegal structures and additions are covered by its enforcement program, so the possible consequences are covered in our Garden Grove code enforcement guide.

State law also gives owners some room: California’s ADU laws, as explained in our unpermitted work guide, mean that a unit that could be legalized under current rules may be easier to bring into compliance than owners expect. A checklist:

• Confirm what exists on the lot and whether any of it was permitted.
• Compare it with the current size, height, setback and parking standards above.
• Ask Planning at (714) 741-5312 whether the unit could qualify for approval and what it would require.
• Get a contractor estimate for any corrections, plans and fees.
• Weigh that cost against selling as-is.

How an ADU affects selling your house

A permitted ADU can add rental income and value, but it also adds items for a buyer to review: permits, final inspection records, utility arrangements and whether the unit is rented. An unpermitted unit creates disclosure duties and may limit financing.

A cash buyer purchases the property in its current condition, which is often the simpler path for an owner who does not want to fund permit work or deal with tenants during a listing.

How to sell a house in Garden Grove

1. List what is on the property, including any ADU, converted garage or additions.
2. Collect permits, final inspections and leases.
3. Request a no-obligation cash offer for the house as it stands.
4. Choose a closing date.
5. Close with no repairs, permits or showings.

See also: sell as-is in Garden Grove, sell fast, cash home buyers and the cash offer process.

Frequently asked questions

How many ADUs can I build on a single-family lot in Garden Grove?

The city allows one ADU and/or one junior ADU on a single-family lot.

How big can a detached ADU be?

Up to 850 square feet for a studio or one bedroom and up to 1,200 square feet for two or more bedrooms.

Do I need to live on the property?

Not for a standard ADU. A junior ADU requires owner occupancy.

Can I rent my ADU short term?

No. Rentals must be for 30 days or longer, and the ADU cannot be sold separately from the main house.

How long does the city take to review an ADU application?

The city must review complete applications ministerially within 60 days, or 30 days for a pre-approved plan.

Can I sell a Garden Grove house with an unpermitted ADU?

Yes. You can disclose it and sell as-is, including to a cash buyer.

More guides

• We Buy Houses in Garden Grove
• We Buy Houses in Orange County
• Orange County Property Tax Guide
• Garden Grove Building Permits Guide
• Garden Grove Code Enforcement Guide
• All California Guides

Sources

• City of Garden Grove: ADU Program
• Garden Grove Municipal Code, Chapter 9.54 Accessory Dwelling Units
• City of Garden Grove: Code Enforcement FAQs

This guide is general information from public sources, not legal advice. Confirm current rules with the city.