Fast, Reliable New Detached ADU Across Irvine
A new detached ADU in Irvine typically runs $220,000-$380,000 all-in, from permit set through final inspection, with timelines stretching 8-14 months due to the city’s unique dual-track approval process. We serve homeowners from Woodbridge to Portola Springs, with crews dispatched locally and scheduling coordinated from our Los Angeles office. Call (657) 233-9738 to schedule your free estimate - every project receives a written price before any work begins, per Haven Standard Clause 1.
We’ve designed, permitted, and built over 900 ADUs since 2015, the year California’s ADU laws shifted. Our New Detached ADU team understands what opening up an older Irvine home actually turns up: outdated wiring, undersized framing, failed waterproofing, and the code upgrades a permit triggers once walls are open. That’s why we inspect first, write allowances into every contract, and price any surprise in writing before we touch it.
Why Ellery ADU Studio Irvine Is Irvine’s Preferred New Detached ADU Company
We’re not contractors who draw. We’re a design-build studio - one contract, one written price, no designer-versus-builder blame gap. Since 2015, every one of our 900+ ADUs has started with a written quote and ended with a documented photo record. Our license number appears on every page, verified, not just claimed.
Our crews serve Irvine locally, and a live person answers calls 24/7. No voicemail queue. No callback promise that doesn’t materialize.
We know Irvine’s villages. Woodbridge’s Mediterranean streetscapes. Turtle Rock’s hillside lots with their setback challenges. The compact zero-lot-line parcels in newer villages where detached ADUs fight for every inch. This matters because an out-of-area builder who misses your ARC’s faux-door requirement or specifies the wrong roofline doesn’t just delay you - they cost you a redesign.
Our Free Second Opinion applies to any written estimate already in hand. Bring us another firm’s quote and we’ll tell you what’s accounted for, what isn’t, and what Irvine’s dual-track approval will actually require.
Our New Detached ADU Services in Irvine
Custom Built ADU
Custom built ADUs in Irvine run $280,000-$380,000, drawings through final inspection. Every custom project begins with a site measure and a documented conditions report - we photograph what’s there before we design what’s next. In Irvine, this step is non-negotiable. Your village’s Architectural Review Committee will reject rooflines, finishes, or colors that don’t mirror the established theme, and the City of Irvine won’t issue a building permit until ARC sign-off is complete. We design for both tracks simultaneously, not sequentially, shaving weeks off timelines that out-of-area builders routinely underestimate.
In Woodbridge, we opened up an older home and found outdated wiring and undersized framing. Our tech documented the issues, got written approval for upgrades, and built a detached ADU with James Hardie siding carefully chosen to match the village’s Mediterranean theme. That’s the 365-Day Done Right Promise in practice - if it’s not built to the permitted drawings, we make it right, in writing, before the project starts.
Prefab ADU Installation
Prefab ADU installation in Irvine typically runs $220,000-$320,000. We specify and coordinate systems from Abodu, Cover, and Mighty Buildings - brands whose exterior palettes we vet against village-specific ARC requirements before any deposit changes hands. Prefab doesn’t bypass Irvine’s dual-track approval; it compresses the construction timeline while the permit and ARC processes run in parallel. In east-side villages like Portola Springs and Orchard Hills, where summer highs routinely hit the upper 80s and 90s, we specify Title 24 cool-roof packages and attic insulation upgrades as standard, not optional. Failed inspections for thermal compliance are expensive rework we prevent at the specification stage.
Modular ADU
Modular ADUs in Irvine fall in the $240,000-$340,000 range. Dvele and Plant Prefab systems arrive as completed modules, crane-set onto foundations we prep and permit as part of the same contract. Crane access is a real constraint in Irvine’s compact lots - we survey utility lines, neighbor setbacks, and street tree canopies before quoting, not after. Under Haven Standard Clause 5 (No Surprises), that scope is locked at signing. No door-side upsells. No scope creep.
Studio ADU & 1-Bed & 2-Bed ADU
Studio ADUs in Irvine start around $220,000; 1-bedroom units run $260,000-$320,000; 2-bedroom configurations reach $320,000-$380,000. Size drives cost, but so does infrastructure. Older Irvine homes - much of the stock built between the 1970s and 2010s under the Irvine Company’s village plans - often need electrical service upgrades to support a detached unit. We find this during inspection, price it into the written quote, and document it with photos. You receive evidence of what we found, not a summary of how it felt.
What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Irvine
We specify and coordinate prefab and modular systems from Abodu, Cover, Dvele, Mighty Buildings, Boxabl, Plant Prefab, Tuff Shed, and James Hardie - all within the same single contract. For Irvine’s ARC environment, brand fluency matters. James Hardie siding, for instance, offers color palettes that map cleanly onto Woodbridge’s Mediterranean themes and Northwood’s Craftsman vocabulary. We don’t stock parts in a warehouse; we coordinate factory delivery to align with your permit release and ARC approval, minimizing site storage and weather exposure. Our crews are background-checked, uniformed, and trained on each system’s installation protocol - no learning on your job.
Common New Detached ADU Problems We See in Irvine Homes
- ARC design rejection. Proceeding without pre-approval for rooflines, finishes, or colors that mirror the village’s architectural theme leads to costly redesigns and delays. We submit to your ARC before the City, not after, catching conflicts early.
- Outdated infrastructure surprises. Opening walls reveals outdated wiring or undersized framing not accounted for in initial quotes, causing budget overruns if not handled with allowances upfront. Our inspection-first protocol documents conditions before design, and Haven Standard Clause 3 requires written approval for any change.
- Title 24 cool-roof non-compliance. In Irvine’s inland heat, failing to install cool roofs and proper attic insulation results in failed inspections and rework. We specify compliance-grade assemblies as standard, particularly for east-side villages with weaker marine layer relief.
- Setback miscalculations on compact lots. Many Irvine villages, especially townhome areas and zero-lot-line developments, have tighter setbacks than unincorporated Orange County. We measure twice, permit once, and never assume standard setbacks apply.
Pricing for New Detached ADU in Irvine, CA
| ADU Type | Typical Range (Irvine) | What Drives Cost |
|---|---|---|
| Studio ADU | $220,000-$280,000 | Foundation type, utility trench length, ARC finish requirements |
| 1-Bed ADU | $260,000-$320,000 | Kitchen/bath spec, electrical service upgrade, cool-roof assembly |
| 2-Bed ADU | $320,000-$380,000 | Square footage, HVAC zoning, dual egress requirements |
| Prefab/Modular | $220,000-$340,000 | Brand selection, crane access, module count |
These ranges reflect all-in pricing: permit set, City of Irvine fees, ARC submission support, construction, and final inspection. What moves a quote within the range? Foundation conditions, electrical service capacity, and the specific ARC finish tier your village requires. We don’t say “it depends” without telling you what it depends on. Every project receives a written price before any work begins - Haven Standard Clause 1. No exceptions. Call (657) 233-9738 for your free estimate.
We Also Serve Cities Near Irvine
Our crews work throughout central Orange County, including Irvine, Tustin, Santa Ana, Orange, and Lake Forest. Each city has its own permitting rhythm - Santa Ana’s less HOA-dense environment skips the ARC layer entirely, while Lake Forest’s newer developments carry their own design review. We adjust our process to match, never forcing an Irvine-shaped template onto a different jurisdiction.
Serving Irvine, CA - Our Local Coverage Area
We’re based in the Irvine 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 - New Detached ADU in Irvine
Outdated infrastructure hidden in walls - wiring, framing, or foundation conditions that inspection couldn’t reach until demolition. We prevent this with a pre-design site inspection, photo documentation, and written allowances in every contract. Under Haven Standard Clause 3, any surprise is priced and approved in writing before we proceed. Call (657) 233-9738 for an exact quote - estimates are free.
Yes. California Civil Code §4751 bars HOAs from prohibiting ADUs outright, but Irvine’s Architectural Review Committees still enforce village-specific design standards on rooflines, exterior finishes, and colors. This creates a mandatory dual-track approval - City permit plus ARC sign-off - that adds 3-6 weeks compared to less HOA-dense neighboring cities like Santa Ana or Lake Forest. We design for both tracks simultaneously to compress that delay. Call (657) 233-9738 to discuss your village’s specific ARC requirements.
Woodbridge’s Mediterranean theme requires stucco or textured siding in approved earth-tone palettes, clay-tile or compatible composite roofing, and often a faux-door facade if the ADU replaces a garage streetscape. We specify James Hardie products with ARC-preapproved colors and document the match in the permit set. Call (657) 233-9738 and we’ll review your specific street’s requirements.
Portola Springs sits far enough inland that marine layer relief is weak, with summer highs routinely in the upper 80s-90s°F. Title 24 mandates cool-roof surfaces and minimum attic insulation R-values for habitability and energy compliance. We specify compliant assemblies as standard; non-compliance means failed inspection and costly re-roofing. Call (657) 233-9738 for a thermal performance quote tailored to your lot’s exposure.
Yes, if the garage is detached from the main house - attached garage conversions are classified as JADUs under California law, with different size and setback rules. Many Irvine villages require retaining the original garage door or installing a matching faux-door facade for streetscape consistency. We price this ARC requirement into the written quote upfront, not after the rejection letter arrives. Call (657) 233-9738 to assess your garage’s conversion potential.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving Irvine and Orange County since 2015.