Fast, Reliable New Detached ADU Across Irvine
A new detached ADU in Irvine typically runs $285,000-$485,000 all-in, from permit-ready drawings through final inspection, with most projects clearing the village ARC and city permit sequence in 90-120 days. We’re Ellery ADU Studio, and our New Detached ADU team coordinates design, permitting, and construction from our Los Angeles office, with crews serving Irvine locally. Call (562) 263-3350 to schedule your free estimate - every project receives a written price before any work starts, per Haven Standard Clause 1.
Why Ellery ADU Studio Huntington Beach Is Irvine’s Preferred New Detached ADU Company
We’ve designed, permitted, and built 900+ ADUs since 2015, the year California’s ADU laws shifted, including many a Garage Conversion ADU - Irvine homeowners count on. Our crew knows the difference between Woodbridge’s ARC portal and Portola Springs’. That matters when a missed village association sign-off can red-tag an otherwise code-compliant slab.
Our Irvine clients receive the same documentation we deliver everywhere: a written price before work starts, a permit set treated as the core product, and a documented photo record on every visit. No designer-versus-builder blame gap. One contract. One written price.
Dispatch and scheduling run from our Los Angeles office, but crews are in Irvine regularly. A live person answers calls 24/7. We also offer a Free Second Opinion on any written estimate already in hand.
Our New Detached ADU Services in Irvine
Custom Built ADU
Custom detached ADUs in Irvine demand more than standard plans because every village association imposes its own design standards. We draw the permit set to match your primary home’s roofline, stucco color, and trim from the start, not as a revision. In Turtle Rock, that meant sourcing a specific James Hardie trim profile to satisfy the ARC before city filing. Custom builds here typically run $320,000-$485,000 all-in, depending on square footage and finish level.
Prefab ADU Installation
We specify and coordinate prefab systems from Plant Prefab and Boxabl within our single-contract model. The factory build shortens on-site duration, but the ARC still reviews exterior finishes before city permits. We manage both sequences. Prefab detached units in Irvine generally fall between $285,000-$395,000, with faster close-in once the slab and utility stub-outs pass inspection.
Modular ADU
Modular construction from brands like Plant Prefab works well on Irvine’s 4,500-7,500 sq ft lots when equipment access is planned early. The crane path and module delivery route get scoped before quoting, not after. Modular detached ADUs in Irvine typically range $295,000-$410,000.
Studio ADU & 1-Bed & 2-Bed ADU
Studio detached units suit narrow rear lots in Northwood and Woodbury where setbacks tighten. One-bedroom and two-bedroom configurations need more attention to Irvine’s 90-95°F summer highs - we size split-system HVAC as a fixed line item, never an upgrade. Studios run $285,000-$350,000; 1-bed units $310,000-$395,000; 2-bed units $340,000-$485,000.
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.
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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 Plant Prefab, Boxabl, and James Hardie within the same single contract that covers your permit set and construction. Our crew has installed James Hardie siding on ARC-compliant detached units across Woodbridge and Portola Springs, matching village-specific color palettes from the factory order. Local material coordination keeps lead times predictable, and we verify every delivery against the approved ARC submission before it hits the lot.
Common New Detached ADU Problems We See in Irvine Homes
- ARC-before-permit sequencing failures. Contractors new to Irvine routinely pull city permits before getting village association sign-off. The result: inspectors flag the unapproved ADU and force aesthetic remediation on an otherwise code-compliant structure. We file ARC first, city second, every time.
- HVAC treated as optional. A detached ADU feels like an outbuilding, so some scopes skip mechanical. Irvine’s inland summer highs of 90-95°F make split-system cooling non-negotiable. We size and specify it as a fixed line item from the first quote.
- Underscoped grading on open lots. Rear yards in newer villages like Portola Springs often carry subtle grade changes that need a designed swale before foundation formwork. We walk the equipment-access path with the hauler and scope grading before quoting, not after the slab pour fails inspection.
- Generic slab specs ignoring local conditions. Irvine’s near-zero frost risk and under-14-inch annual rainfall simplify concrete work, but they don’t eliminate the need for proper drainage planning. We account for both in the permit set.
Pricing for New Detached ADU in Irvine, CA
| Detached ADU Type | Typical All-In Range (Irvine) |
|---|---|
| Studio ADU (detached) | $285,000 - $350,000 |
| 1-Bed ADU (detached) | $310,000 - $395,000 |
| 2-Bed ADU (detached) | $340,000 - $485,000 |
| Custom Built ADU | $320,000 - $485,000 |
| Prefab/Modular ADU | $285,000 - $410,000 |
These ranges include permit-ready drawings, village ARC submission, city permits, construction, and final inspection. What moves the needle: square footage, finish level, lot grading complexity, and equipment-access constraints. Under Haven Standard Clause 1, every project receives a written price before any work starts - no “call for a quote,” no open-ended allowances. Call (562) 263-3350 for your exact number. Estimates are free.
We Also Serve Cities Near Irvine
Our crews work throughout Orange County. If you’re comparing options, we also build New Detached ADU in Irvine neighboring cities: Tustin, Santa Ana, Orange, and Newport Beach. Santa Ana and Anaheim lack Irvine’s village ARC layer, so their permit timelines differ. We adjust the scope accordingly.
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
Yes. Every Irvine village association requires ARC sign-off on exterior design - roofline, stucco color, trim - before the city will accept your permit application. California AB 670 bars HOAs from banning ADUs outright, but ARCs still legally impose aesthetic standards. We manage this dual-approval sequence as standard practice. Call (562) 263-3350 to walk through your village’s specific portal and timeline.
Irvine’s inland location pushes summer highs to 90-95°F regularly, and the California Energy Code treats conditioned ADUs as living space, not outbuildings. A wall-unit or portable cooler won’t pass inspection. We size split-system HVAC as a non-negotiable line item in every detached ADU quote. Call (562) 263-3350 to review the mechanical spec for your lot.
It simplifies some elements. Under 14 inches of annual rainfall and near-zero frost risk reduce the depth and complexity of drainage systems and concrete protection. But open lots in villages like Portola Springs still need designed swales and equipment-access paths scoped before the pour. We walk the grade with the hauler before quoting. Call (562) 263-3350 to schedule a site review.
Exterior aesthetics only: roofline pitch and material, stucco color and texture, trim profile and paint, window style, and sometimes fence or gate design. The ARC does not review interior layout, structural engineering, or code compliance - those stay with the city. Each village runs its own submission portal and fee schedule. We know Woodbridge’s requirements differ from Northwood’s, and we file accordingly. Call (562) 263-3350 to identify your village’s specific checklist.
We walk the lot to verify equipment-access routes for the concrete hauler and module delivery, measure grade changes that need swales or retaining, confirm utility stub distances, and identify your village’s ARC submission requirements. All of this feeds into a written, line-item quote before any work starts - Haven Standard Clause 1. No allowances. No scope creep. Call (562) 263-3350 to schedule your free estimate.
Ready to price your detached ADU? Call (562) 263-3350 for a free, written estimate. Every project includes a documented photo record, a 365-Day Done Right Promise backed in writing, and a live person answering your call 24/7.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving Irvine and Orange County since 2015.