A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Tustin, CA
ADU construction in Tustin runs about $180 – $340 per square foot for a detached unit, and most homeowners can expect a full build to land between $150,000 and $320,000 depending on size, foundation work, and panel upgrades. What makes Tustin jobs different is the housing stock: 1960s – 1980s tract homes on flat lots north of the 5 freeway, many with original 100-amp panels that need upgrading before any accessory dwelling unit gets powered up. We’re Lodgewick ADU Orange County, and we handle ADU builds, garage conversions, and home additions across Tustin under The Kingswell Guarantee. Call (350) 203-6060 for a free estimate.
Why Tustin Homes Are Different
Tustin’s ADU boom is driven by its position near Irvine and the Great Park, where high land values make garage conversions and two-story detached units the only realistic way to add rental income on typical 5,000 – 7,000 sq ft lots. The yards are small, so homeowners push up instead of out. That means more two-story ADUs here than in most Orange County cities, and more attention to second-floor setbacks and privacy screening from neighbors.
The homes themselves are 1960s – 1980s single-family tract builds, mostly wood-frame on slab foundations. Flat lots make site work straightforward, but two things catch homeowners off guard. First, many original 100-amp electrical panels can’t support a new ADU, so a panel upgrade to 200 amps becomes part of the real price. Second, in the older neighborhoods west of Red Hill Avenue, we regularly find cast-iron drain lines under the slab that must be replaced before adding a bathroom. That’s a $4,000 – $8,000 line item most people don’t plan for. We name it in the written estimate before work starts, not after the slab is open.
Climate matters too. Tustin’s Mediterranean pattern means mild winters and hot, dry summers, so ADUs here need cross-ventilation and cool roofing materials more than heavy insulation. In Tustin Ranch and other hillside-adjacent areas, Santa Ana winds push us toward fire-resistant exterior cladding, which is worth budgeting for early.
Our Main Tustin Services
Tustin homeowners most often call us for an accessory dwelling unit on the back half of the lot or a garage conversion when the existing two-car garage isn’t earning its footprint. Each has its own dedicated Tustin page below.
Home Addition Contractor in Tustin
A home addition in Tustin usually means extending the back of a 1960s tract home to add a primary suite or a larger kitchen, working around slab foundations and the small lots that leave little room for staging. One of the recurring issues is the electrical service: adding 600+ square feet of living space almost always triggers a panel upgrade. That’s part of the written price from the start. For the full breakdown on what additions cost in Tustin and how the permit process works here, see Home Addition Contractor in Tustin.
Garage Conversion Contractor in Tustin
Garage conversions are the most common ADU route in Tustin because the structure already exists, the setback is already met, and the cost usually lands well under a detached build. The work involves insulating walls, replacing the garage door with a framed wall and windows, running new electrical from what is often a maxed-out 100-amp panel, and tying plumbing into the existing slab, which is where cast-iron surprises show up west of Red Hill Avenue. Full details are on the Garage Conversion Contractor in Tustin page.
ADU Builders in Tustin
A detached ADU in Tustin works best on the flat lots north of the 5, where a 500 – 700 sq ft unit can sit at the back corner without eating the whole yard. Tustin’s small lots push many homeowners toward two-story units, which changes the engineering and sometimes triggers additional fire-hardening requirements near Tustin Ranch. We walk through lot placement, setbacks, and the actual build cost range on the ADU Builders in Tustin page.
What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Brands We Service in Tustin
We work regularly with Abodu, Cover, and Mighty Buildings prefab systems in Tustin, matching the right unit to each lot’s setback, access, and budget. Need something specific? Our brands page covers the full lineup.
Pricing for ADU Company in Tustin, CA
| Service | Typical range in Tustin |
|---|---|
| Detached ADU (400 – 750 sq ft) | $120,000 – $280,000 |
| Detached ADU, two-story | $250,000 – $450,000 |
| Garage conversion to ADU | $85,000 – $180,000 |
| Garage conversion, detached structure | $110,000 – $160,000 |
| Home addition (400 – 800 sq ft) | $100,000 – $300,000 |
| Primary suite addition | $150,000 – $350,000+ |
| Second-story addition | $180,000 – $450,000 |
| Drywall (per sq ft installed) | $1.50 – $3.50 |
| Electrical panel upgrade to 200 amps | $2,000 – $4,500 |
| Cast-iron drain line replacement under slab | $4,000 – $8,000 |
| Cool roof coating | $2,500 – $6,000 |
| Interior paint (ADU, full) | $3,000 – $8,500 |
The two biggest price movers in Tustin are panel upgrades and hidden cast-iron plumbing. We give you a written price before any work starts, and that price does not change at the door.
Neighborhoods We Serve in Tustin
We work across Tustin, from the older tract streets west of Red Hill Avenue to the newer hillside builds in Tustin Ranch. Crews are usually in the area within one business day for estimates.
- Tustin Ranch
- Old Town Tustin
- West Tustin
- Columbus Square
- Crawford Canyon
Service Area – Cities Near Tustin
We also serve the surrounding Orange County cities. Homeowners in Santa Ana, CA, Costa Mesa, CA, Midway City, CA, and Lake Forest, CA get the same written-price-first approach and The Kingswell Guarantee. Dispatch and scheduling are coordinated from the brand’s Los Angeles office, while crews serve Tustin locally.
Serving Tustin, CA - Our Local Coverage Area
We’re based in the Tustin area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About ADU Company in Tustin
Yes. Tustin requires building permits for all ADUs, garage conversions, and additions. We prepare the plans that go to the city and manage the permit process from submittal through final inspection. You’ll get a written timeline for this before work begins so inspections don’t turn into surprises.
California state law overrides most HOA restrictions on ADUs, but Tustin HOAs can still impose design, setback, and parking rules. We check your specific HOA’s recorded documents before design work so the written plan matches what the association will approve. Call (350) 203-6060 if you want us to review yours.
Most detached ADUs in Tustin take 5 – 9 months from permit submittal to final inspection. Garage conversions run 3 – 5 months. The written estimate includes a build schedule, not just a price. Call (350) 203-6060 to get your project scoped with a real number.
For a written, line-item estimate on any ADU, garage conversion, or home addition in Tustin, call (350) 203-6060. We’ll walk the lot, give you the real number in writing, and stand behind the work with the 365-Day Done Right Promise.
What happens when you call
- 1A real person answersNo phone trees - talk to a local adu pro.
- 2You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
- 3We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
- 4You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.
What Tustin Customers Say
"Solid build on a home addition. The permit stage dragged, which held things up a few weeks. They were upfront it was out of their hands and the construction itself moved fast and clean."
- Douglas Fenwick"Detached unit in the backyard for rental income. They handled design and permits and gave me a real schedule. Came in close to on time and exactly on the written price."
- Benjamin Stahl"Converted our garage into a rental studio. The crew was respectful of the neighbors and kept the site clean. It's bringing in rent now and paid for itself faster than I expected."
- Grace Yoon
