Want more space for family or a steady second income without moving? In Garden Grove, an accessory dwelling unit can help you support loved ones, grow wealth, or both. You care about the rules, the budget, and how fast you can get it done. This guide explains what you can build in Garden Grove, how permits work, what it typically costs, and how to plan for multi‑generational living or long‑term rental. Let’s dive in.
Why ADUs make sense in Garden Grove
ADUs and junior ADUs are allowed citywide on lots zoned for single‑family or multifamily housing. The city’s rules are ministerial, which means your project is reviewed against clear standards with no discretionary hearing if you meet the checklist. Garden Grove also offers city pre‑approved plans to speed up detached ADUs.
If you plan to use the ADU for family now and rent it later, state law helps. For ADUs permitted after Jan 1, 2025, California permanently removed owner‑occupancy requirements, so you generally do not need to live on site to rent the ADU long term. JADUs are different and usually require the owner to live on the property. Short‑term rentals are not allowed for ADUs or JADUs in Garden Grove, so think 30 days or longer.
- Read the city’s ADU rules in the municipal code for the exact standards. Garden Grove Municipal Code Chapter 9.54
- Learn how state law shapes local practice in the California HCD ADU Handbook.
- See the state rule on owner‑occupancy in AB 976.
What you can build in Garden Grove
Garden Grove’s code sets clear limits for size, height, setbacks, and parking. Here are the highlights you will use most when planning.
- Where allowed. ADUs and JADUs are allowed on any lot with a primary dwelling in zones that permit residential use.
- How many. A single‑family lot can have up to one ADU and one JADU if you meet size and placement rules. Multifamily parcels can add more detached ADUs under quantified caps.
- Size. Detached ADUs can be up to 850 square feet for a studio or one bedroom, and up to 1,200 square feet for two or more bedrooms. Attached ADUs are limited by a percentage of the primary home, with caps. Conversions, like garages turned into living space, follow different limits if you are not adding floor area.
- Setbacks and separation. Standard side and rear setbacks are at least 4 feet for new attached or detached ADUs. Keep at least 6 feet of building separation between a detached ADU and the primary home. Converted ADUs usually do not require new setbacks.
- Height. Detached ADUs are typically limited to 16 feet, with some 18‑foot allowances in specific situations. Attached ADUs can be up to 25 feet or the height of the primary home and cannot exceed two stories.
- Parking. One off‑street space is required for a new attached or detached ADU, with several exceptions. No parking is required if your lot is within one‑half mile of transit or for certain conversions. Tandem parking and using setback areas can be allowed.
- Fees. Impact fees are waived for ADUs under 750 square feet. Larger units may owe proportionate impact fees. Plan‑check, building permit, and utility connection or capacity charges still apply.
For exact definitions and any special cases, see Garden Grove Municipal Code Chapter 9.54.
Speed your project with ADU Go
Garden Grove’s pre‑approved plan library, ADU Go, can cut design time and speed permits for detached units. The city offers plan templates around 447 square feet (studio), 630 square feet (1‑bed), 750 square feet (2‑bed), and 1,000 square feet (3‑bed). If one of these fits your site, it can help you reach approvals faster and reduce soft costs. Explore options at ADU Go.
Choose the right ADU type
Your lot, budget, and goals will steer the design. Here are common paths that fit Garden Grove homes.
Garage conversion
Converting an existing attached or detached garage is often the most affordable route. Conversions are treated differently in the code and commonly do not require new setbacks. They can also avoid replacement parking when you convert the space. Confirm that the structure was legally built and that utility upgrades are feasible. See standards in Chapter 9.54.
Detached backyard cottage
A new cottage behind the main home gives strong privacy for relatives or tenants. Plan for the 4‑foot side and rear setbacks, 6‑foot separation from the main house, and utility clearances. ADU Go includes detached layouts that can reduce plan time. Check exact placement rules in the municipal code and match them to an ADU Go template if possible.
Attached or second‑story ADU
If your lot is tight, an attached addition or a second‑story ADU above part of the home or garage can work. Attached ADUs can reach up to 25 feet in height, not exceeding two stories. You will need structural review and Title 24 energy compliance. Details are in Chapter 9.54.
Junior ADU (JADU)
A JADU is up to 500 square feet carved from the interior of the primary home or an attached garage. It requires an owner‑occupancy deed restriction, and it must share utilities with the main home. JADUs are useful for live‑in caregivers or family members who do not need a full kitchen. Read the JADU rules in the city code.
Permits and timeline
Garden Grove uses a ministerial plan‑check process, so timing is predictable when your submittal is complete.
- Start with a quick call to Planning to confirm zoning and fit.
- Prepare a complete plan set and documents listed in the city’s ADU checklist. Submit through the GG Ready portal.
- Plan‑check timing is 60 days for a complete ADU or JADU application. If you use a city pre‑approved plan for a detached ADU, the decision window can be about 30 days, subject to completeness and any requested corrections.
- After approval, standard inspections lead to final sign‑off.
Get the current submittal list in the Garden Grove ADU Checklist and Application and see broader state context in the HCD ADU Handbook.
Budget and income basics
Every site and scope is different, but recent Orange County estimates offer useful guardrails for planning.
- Garage conversion. Often about $80,000 to $150,000 depending on upgrades and finishes.
- New detached ADU, 600 to 1,200 square feet. Commonly $200 to $400+ per square foot. Total projects often range $175,000 to $400,000+ with site work and utilities.
These are ballpark ranges and can change with labor, materials, utility trenching, grading, or special inspections. Review up‑to‑date estimates from local contractors like this regional guide: ADU cost overview.
For income planning, Garden Grove one‑bedroom apartment rents often land in the low‑$2,000s, depending on condition and location. A well‑finished one‑bedroom ADU can be competitive with that market band. Check current listings to fine‑tune assumptions. For a snapshot, see Garden Grove rent trends. Remember, ADUs must be rented for 30 days or longer and short‑term rentals are not allowed under city rules.
Finally, impact fees are waived for ADUs under 750 square feet in Garden Grove, though you will still pay plan‑check, building permits, and any utility connection or capacity charges. New construction usually increases assessed value, so contact the county assessor to understand property tax impacts before you build.
Financing your ADU
Many owners use a combination of home equity and construction financing. Common options include:
- HELOC or home‑equity loan for smaller scopes or conversions.
- Construction‑to‑permanent loans for ground‑up builds.
- Fannie Mae’s HomeStyle Renovation, which can finance ADU construction as part of a mortgage. Learn how lenders underwrite ADUs with Fannie Mae’s ADU guidance.
Ask lenders about interest‑only draws during construction, rate locks, and how projected ADU rent can be considered in your application.
Practical planning checklist
Use this quick list to stay organized from idea to permit.
- Confirm zoning and that your lot has a legally permitted primary home.
- Compare ADU Go pre‑approved plans to your backyard dimensions and goals.
- Order a site assessment that checks easements, utility locations, and any flood or slope issues.
- Get two itemized bids with allowances for utilities, finishes, and inspections.
- Build your submittal package with the city checklist and submit through GG Ready.
- Review insurance with your agent and check any HOA or CC&R rules early.
Find plan requirements in the City ADU Checklist and design options in ADU Go.
Have an older, unpermitted unit?
California created a path to legalize some unpermitted ADUs or JADUs built before January 1, 2020. If you have a converted space that houses family or a tenant, review the city’s guidance and see if your unit qualifies for a corrective permit under AB 2533. Start with the city’s overview here: AB 2533 information.
Ready to plan your ADU?
Whether you want a quiet place for parents, space for a returning grad, or a long‑term rental, an ADU can add flexibility and value to your Garden Grove property. If you want help sizing the opportunity, comparing build paths, or connecting with trusted local pros, let’s talk. Schedule your free consultation with Elizabeth Sanchez.
FAQs
Owner occupancy rules for ADUs in Garden Grove
- For ADUs permitted after Jan 1, 2025, you generally do not need to live on site to rent the ADU long term. JADUs usually require owner occupancy.
Garden Grove ADU permit timeline and steps
- Plan‑check is ministerial with a typical 60‑day review for complete submittals. Using a city pre‑approved plan for a detached ADU can shorten review to about 30 days.
Parking and transit exceptions for ADUs
- One off‑street space is required for new ADUs, unless an exception applies. No parking is required within a half‑mile of transit or for certain conversions.
Short‑term rental rules for ADUs and JADUs
- Short‑term rentals under 30 days are not allowed for ADUs or JADUs in Garden Grove. Plan for month‑to‑month or longer leases.
Typical ADU costs in Orange County
- As a planning range, garage conversions often run about $80,000 to $150,000. New detached ADUs commonly range from $200 to $400+ per square foot depending on finishes and site work.
