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ADU design-build · TustinADUs in Tustin
Old Town charm on one side, newer neighborhoods on the other: in Tustin, the right ADU depends on where your house sits, and we check that first.
What applies to your lot
Building an ADU in Tustin
Who approves your ADU
City of Tustin: ADUs follow Section 9279 of the Tustin City Code, reviewed by Community Development and updated again in 2026. State law applies everywhere: a decision within 60 days of a complete application, no public hearing, and at least 800 sq ft with 4 ft side and rear setbacks.
Old Town Cultural Resource District
Old Town Tustin is a Cultural Resource District. ADUs are allowed there, with a design that respects the historic setting.
The state-guaranteed ADU
An ADU of up to 800 sq ft, 16 ft tall, with 4 ft side and rear setbacks is guaranteed by state law on a qualifying lot, even where other limits apply.
Junior ADUs
A junior ADU of up to 500 sq ft can be created inside the house or an attached garage, in addition to a detached ADU.
California law, everywhere
The rules every city must respect
800 sq ft
Every city must allow at least an 800 sq ft detached ADU with 4 ft setbacks.
4 ft
Maximum side and rear setback for a new detached ADU.
750 sq ft
No impact fees up to this size.
60 days
To approve or deny a complete application, without a hearing.
Ideas for your lot
Plans that suit Tustin lots
1 bedroom
L-shaped one-bedroom
1 bed1 bath
2 bedrooms
Compact two-bedroom
2 beds1 bath
FAQ
ADU questions in Tustin
Who approves an ADU in Tustin?
The City of Tustin, through its Community Development Department.
Can I build in Old Town?
Yes. The Cultural Resource District adds design review; it does not ban ADUs.
Do you come to my property?
Yes. The visit is free: we look at the lot, the access and the utilities, then give you a realistic estimate.
Free feasibility call
Book a free 15-minute feasibility call
A project lead reviews your address, tells you what your lot can hold and gives you a first look at your financing eligibility.
What you get
- Free, with no obligation
- A clear answer on what your lot can hold
- A first look at financing eligibility, by phone or at your property
- A site visit only if it makes sense
Prefer to talk now? (424) 448-4895
Email: [email protected]
Los Angeles, CA · We come to your property
1 · Preferred time2 · Your property3 · Confirmed
Preferred day (Pacific time)
Preferred time
Tell us when to call you. A project lead calls you back at that time of day (Pacific time).
Your call is booked
We’ll confirm by text or phone. No obligation.
Service areas
Serving homeowners across Los Angeles
Los Angeles, the South Bay and Orange County, within about 40 miles of Paramount. Farther on request.
Service areas
ADU rules, city by city
Permits, fire and coastal zones, pre-approved plans: see what applies in the 36 cities we serve.
Central Los AngelesSan Fernando ValleyThousand OaksSimi ValleyParamountWest AdamsMid-CityCulver CityLong BeachDowneyWhittierNorwalkTorranceInglewoodComptonCarsonAnaheimSanta AnaIrvineHuntington BeachPasadenaGlendaleBurbankRialto (on request)Garden GroveOrangeFullertonCosta MesaNewport BeachTustinSherman OaksEncinoVan NuysWoodland HillsNorthridgeCalabasas