Fast, Reliable New Detached ADU Across Irvine
A new detached ADU in Irvine typically runs $220,000-$420,000 all-in, from permit-ready drawings through final city inspection, with most projects taking 10 to 14 months from signed contract to certificate of occupancy. That timeline is longer than elsewhere in Orange County because Irvine’s village Architectural Review Committees add a second approval track on top of City of Irvine permits. If you’re in Woodbridge, Northwood, or Turtle Rock, your project clears two desks, not one.
We serve Irvine from our Los Angeles office, with crews working locally across the city. Call (657) 567-6590 to schedule your free estimate. We’ll bring a written price, a preliminary site assessment, and the actual HOA submittal packet we’ve filed in your village before.
Why Ellery ADU Studio Garden Grove Is Irvine’s Preferred New Detached ADU Company
We’ve designed, permitted, and built ADUs in Irvine since 2015 - the same year California’s ADU laws began shifting. In that time we’ve filed permit sets and HOA architectural packets across more than a dozen Irvine Company villages. Our license number appears on every page, and our crews are background-checked and uniformed.
Our New Detached ADU team has completed 900+ ADU projects statewide, every one with a written price before work started and a documented photo record when work was complete. In Irvine specifically, we’ve learned which villages move fast, which committees scrutinize roof tile profiles, and where zero-lot-line lots eliminate the detached option entirely. That local knowledge keeps projects from stalling.
A live person answers our phones 24/7. No voicemail queue, no callback that doesn’t materialize. And we offer a Free Second Opinion on any written estimate already in hand - bring us another builder’s scope and we’ll flag what’s missing.
Our New Detached ADU Services in Irvine

Custom Built ADU
Custom built ADUs in Irvine run $280,000-$420,000 all-in, drawings through final inspection. This is the right path when your village ARC demands exact material matching - stucco color, roof tile profile, garage door style - that prefab systems can’t replicate. We design the permit set in-house, submit to both City of Irvine and your HOA committee simultaneously, and lock the scope at signing under Haven Standard Clause 5 (No Surprises). No door-side upsells, no scope creep.
In villages like Woodbridge and Northwood, we’ve learned to front-load the ARC packet with physical samples rather than renderings. Committees there reject digital color matching. We know this because we’ve filed in both villages multiple times.

Prefab ADU Installation
Prefab ADU installation in Irvine typically runs $220,000-$340,000, including site prep, foundation, utility tie-ins, and all permits. We specify and coordinate systems from Abodu, Cover, and Dvele within our single contract. The advantage is factory precision; the constraint is ARC flexibility. If your village committee mandates a specific roof tile or stucco finish, we specify that with the factory before production starts - not after delivery.
We’ve installed Abodu units in Portola Springs and Great Park Neighborhoods where newer HOA standards are strict but the lots accommodate detached structures. The factory lead time and the ARC review cycle run in parallel, which we schedule deliberately.

Modular ADU
Modular ADUs in Irvine range $240,000-$380,000, including crane set, foundation, and finish work. Modular construction - built to California Factory-Built Housing standards - can compress the on-site build calendar, but it does not compress the dual-track approval timeline. We file the City of Irvine permit and the village ARC packet together, then release the factory build only after both tracks clear. Starting factory production on a single-track approval is how out-of-town builders end up with a finished module and no place to set it.

Studio ADU & 1-Bed & 2-Bed ADU
Studio ADUs in Irvine start around $220,000; 1-bed units run $260,000-$340,000; 2-bed units run $320,000-$420,000. The bedroom count drives foundation size, septic or sewer capacity, and fire separation requirements - not just interior finish. In hillside villages near Loma Ridge, a 2-bed detached ADU may trigger additional egress window requirements and larger fire setbacks.
We size the unit to the lot, not the wish list. In Turtle Rock and University Park, we’ve steered homeowners from 2-bed to 1-bed ADUs because the lot coverage math didn’t work - and we documented that in writing before anyone signed.

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.
Before
AfterTrusted 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 our single design-build contract. In Irvine, we most frequently specify James Hardie siding and Abodu systems because both accommodate the material-matching demands of village ARCs. We keep sample libraries on hand for committee submittals, and we know which factories can produce custom color matches without voiding warranties. That brand fluency means we don’t hand you off to a separate supplier when the committee rejects a finish.
Common New Detached ADU Problems We See in Irvine Homes

- ARC rejection mid-build. Out-of-town builders bid a detached unit before checking village design standards. Stucco color, roof tile, or garage door style gets rejected after framing is up, forcing rework that adds $15,000-$40,000. We file the ARC packet before breaking ground - always.
- Chapter 7A cost surprise on hillside lots. Properties near Loma Ridge in Shady Canyon, Turtle Ridge, and Orchard Hills fall within High Fire Hazard Severity Zones. Ignition-resistant exterior materials are required, not optional. We price this in the written quote, not as a change order later.
- Slab and framing exposed during approval gaps. Crews start construction before dual-track sign-off, leaving a half-built shell weathering for weeks while the City and HOA move on separate calendars. We sequence trades so nothing sits exposed.
- Detached ADU sold on unbuildable lots. Attached townhomes and zero-lot-line detached homes in villages like Westpark and Rancho San Joaquin can’t legally support a detached unit. We assess this in the first site visit and document it, steering those homeowners toward garage conversions or JADUs instead.
Pricing for New Detached ADU in Irvine, CA
New detached ADU pricing in Irvine runs higher than the Orange County average because of the dual-track approval calendar and the material-matching requirements that come with it. Here’s what we see in the current market:
| ADU Type | Typical Range (Irvine) | What’s Included |
|---|---|---|
| Studio ADU | $220,000-$280,000 | Drawings, permits, foundation, utility tie-ins, finish |
| 1-Bed ADU | $260,000-$340,000 | Above plus full kitchen, bath, bedroom separation |
| 2-Bed ADU | $320,000-$420,000 | Above plus second bedroom, additional egress, larger MEP |
| Custom Built (any size) | $280,000-$420,000 | Architectural matching, ARC coordination, premium finishes |
| Prefab/Modular | $220,000-$380,000 | Factory unit, site prep, crane set, finish, permits |
Factors that push Irvine projects toward the top of these ranges: village ARC material-matching requirements, Chapter 7A ignition-resistant materials on hillside lots, complex utility trenching in older villages with narrow side yards, and foundation work on sloped sites near Loma Ridge. Every project is quoted with a written price before any work begins, per Haven Standard Clause 1. No exceptions. Call (657) 567-6590 for your written estimate - estimates are free.
We Also Serve Cities Near Irvine

Our crews work throughout central Orange County. We also build New Detached ADU in Irvine for homeowners in Tustin, Santa Ana, Orange, and Newport Beach - each with its own permit timelines and, in some cases, their own architectural review layers. The dual-track system we manage in Irvine prepares us well for similarly structured communities.
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

You need both. AB 3182 and SB 13 prevent HOAs from outright banning ADUs, but they do not eliminate design review. Irvine’s village Architectural Review Committees still control stucco color, roof tile profile, garage door style, and setback aesthetics - and they enforce these standards across dozens of villages. We file your ARC packet and City of Irvine permit simultaneously, so neither track waits on the other. Call (657) 567-6590 and we’ll show you the actual submittal packet for your village.
It depends on your lot configuration. Attached townhomes and zero-lot-line detached homes - common in Westpark, Rancho San Joaquin, and parts of Woodbridge - often cannot support a detached ADU legally or physically. We assess lot coverage, setbacks, and utility access in our first site visit and document what will and won’t work. If a detached unit isn’t viable, we quote a garage conversion or JADU under the same single contract. Call (657) 567-6590 to schedule that assessment.
Yes, typically by $8,000-$18,000. Hillside villages like Shady Canyon, Turtle Ridge, and Orchard Hills fall within or adjacent to High Fire Hazard Severity Zones, requiring ignition-resistant exterior materials under Chapter 7A of the California Building Code. This means James Hardie siding or equivalent, tempered glazing in specific locations, and sometimes enhanced roof assemblies. We price this in the written quote, not as a surprise change order. Call (657) 567-6590 for an exact figure on your lot.
We do. Under our design-build contract, Ellery ADU Studio prepares and files both the City of Irvine permit set and your village’s ARC packet. You sign the applications, but we handle the submittal, the revision cycles, and the resubmittals. In Northwood, we once pulled the city permit while the ARC was still cycling on stucco and roof tile - our tech matched the primary home’s color and tile exactly on the first submittal, then scheduled framing and rough MEP so the slab was never sitting exposed. That’s the sequencing that protects your timeline and your foundation. Call (657) 567-6590 to discuss your village’s specific requirements.
We don’t start work that can be weather-damaged or code-violated until both tracks clear. Specifically: we file simultaneously, we design the ARC packet for first-round approval (physical samples, not renderings, in villages that require them), and we sequence trades so slab and framing happen after sign-off, not before. The 6 to 10 weeks of ARC review happens while we finalize engineering and order long-lead materials - never while concrete is curing or framing is exposed. This is standard in our Irvine projects. Call (657) 567-6590 and we’ll walk through the calendar for your specific village.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving Irvine since 2015.