ADU in Irvine, CA
A Junior ADU or interior conversion in Irvine typically runs $85,000-$165,000 all-in, while site prep and utility work for detached units adds $35,000-$75,000 before construction begins. We’re Ellery ADU Studio, and we handle both under one contract at one written price. Call (562) 263-3350 to schedule your free estimate.
Irvine’s master-planned villages - Woodbridge, Northwood, Turtle Rock, Woodbury, Portola Springs - were built in phased clusters from the 1970s forward, with nearly every home sitting under an Architectural Review Committee that must approve exterior work before city permits are filed. That dual-approval reality shapes every Junior ADU & Interior Conversion we design here, and every ADU Site Prep & Utilities package we coordinate.
Why Irvine Homes Are Different
Irvine’s housing stock is almost entirely tract construction on 4,500-7,500 sq ft lots with attached two-car garages. These garages were never conditioned, so every garage conversion demands full HVAC, insulation, and vapor barrier retrofits. Summer highs hit 90-95°F regularly, making split-system cooling non-negotiable. The near-zero frost risk and under 14 inches of annual rainfall simplify slab work but do not eliminate it.
The defining local factor is the HOA gauntlet. California AB 670 bars outright ADU bans, yet Irvine’s village ARCs legally enforce design standards - matching rooflines, stucco colors, trim materials - adding 30-60 days to every project. Contractors who pull city permits before ARC sign-off risk flagged inspections and costly aesthetic remediation. We sequence ARC approval first, every time.
Our Main Irvine Services
Three services have dedicated Irvine pages with full pricing and neighborhood specifics:
ADU Design & Permitting in Irvine
Our permit set is the core product - construction documents, Title 24 energy calculations, and city submittal - prepared in-house before any builder touches the site. In Irvine, we front-load ARC package preparation because city staff will ask for documented HOA approval at intake. ADU Design & Permitting in Irvine covers the full process from measured drawings to issued permit.
Garage Conversion ADU in Irvine
The dominant Irvine project type: converting an attached two-car garage on a 5,000 sq ft lot into a 400-640 sq ft dwelling unit. Every job needs slab assessment, firewall upgrades, and dedicated HVAC because these spaces were built for storage, not occupancy. Garage Conversion ADU in Irvine details our full scope and pricing.
New Detached ADU in Irvine
Detached units on Irvine’s compact lots require precise setback calculations - often 4 feet side and rear - and utility trenching from the main house. We coordinate prefab systems from Boxabl and Plant Prefab within our single-contract model when site conditions allow. New Detached ADU in Irvine explains our design-build process.
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.
Junior ADU & Interior Conversion in Irvine
Junior ADU & Interior Conversion in Irvine solves the problem of adding rental income or multigenerational space without exterior construction that triggers ARC review. Most Irvine homes have underutilized square footage - basements never finished, rooms above garages, attached wings - that can be converted under JADU provisions with no new footprint. Interior work still needs permits and inspections, but it bypasses the 30-60 day ARC timeline that slows exterior projects across Woodbridge, Northwood, and Turtle Rock.
Room-to-ADU Conversion
Signs you need it
An attached bedroom or den sits unused while you need rental income or space for family, and the primary residence has its own kitchen and exterior door already.
What it costs in Irvine
Room-to-ADU conversions in Irvine typically run $85,000-$140,000 including permit-ready drawings, mechanical upgrades, and final inspection.
How we do it
We measure existing conditions, design the separation wall and mini-split layout, submit the JADU permit set to Irvine’s Community Development Department, and build to the drawings under our 365-Day Done Right Promise.
Above-Garage ADU
Signs you need it
Your garage has unfinished space above with ceiling height at or near 8 feet, and the floor joists can be reinforced to support residential loading.
What it costs in Irvine
Above-garage ADUs in Irvine typically run $110,000-$165,000 including structural engineering, stair access, and full MEP rough-in.
How we do it
We verify joist capacity with a structural engineer, design the stair and egress window layout, and coordinate fire separation between garage and living space per Irvine’s amended California Building Code requirements.
What Junior ADU & Interior Conversion Costs in Irvine
| Item | Typical range in Irvine |
|---|---|
| Room-to-ADU conversion (drawings through final) | $85,000-$140,000 |
| Above-garage ADU with structural reinforcement | $110,000-$165,000 |
| Interior JADU (existing space, no footprint change) | $75,000-$125,000 |
Does a Junior ADU need HOA approval in Irvine?
No - if the work is entirely interior with no exterior changes visible from the street, most Irvine village ARCs do not require review, though we verify your specific CC&Rs before starting. Call (562) 263-3350 and we’ll check your association’s requirements during your free estimate.
How long does a room-to-ADU conversion take?
Permitting takes 8-12 weeks in Irvine, and construction runs 10-14 weeks for a typical room conversion with no structural surprises. We lock the timeline at contract signing under Haven Standard Clause 5 - no surprises.
ADU Site Prep & Utilities in Irvine
ADU Site Prep & Utilities in Irvine addresses the gap between a permitted design and a buildable site: trenching across compact lots, upgrading 1970s-era electrical panels, and extending gas lines from the meter to a new detached unit. Irvine’s master-planned infrastructure is reliable but often undersized for ADU loads, especially in villages built before 1990 where 100-amp panels and 3/4-inch gas lines were standard. We assess capacity before construction starts, not after drywall is up.
Electrical Panel Upgrade
Signs you need it
Your existing panel is 100 amps or dated before 1990, and the ADU adds a kitchen, laundry, and HVAC load that pushes total service past capacity.
What it costs in Irvine
Electrical panel upgrades for Irvine ADUs typically run $4,500-$8,500 including SCE coordination, permit, and inspection.
How we do it
We calculate combined load for main house plus ADU, specify 200-amp service if required, and schedule Southern California Edison meter spot and final with Irvine inspection.
Plumbing Lateral
Signs you need it
Your detached ADU site sits more than 30 feet from the main sewer cleanout, or the existing lateral is terra-cotta or Orangeburg pipe common in 1970s Irvine construction.
What it costs in Irvine
Plumbing lateral extensions in Irvine typically run $8,000-$18,000 including trenching, permit, and city inspection.
How we do it
We video-inspect the existing line, design the slope and cleanout placement to Irvine’s amended IPC standards, and trench with minimal disturbance to established landscaping.
What ADU Site Prep & Utilities Costs in Irvine
| Item | Typical range in Irvine |
|---|---|
| Electrical panel upgrade (100A to 200A) | $4,500-$8,500 |
| Plumbing lateral extension | $8,000-$18,000 |
| Gas line extension to detached ADU | $3,500-$7,500 |
Will SCE require a service upgrade for my ADU?
Most pre-1990 Irvine homes need 200-amp service when adding a full ADU with electric appliances; we confirm with a load calculation before permit submittal. Call (562) 263-3350 and we’ll assess your panel during the free estimate.
Can you trench under existing hardscape?
Yes - we use directional boring under concrete driveways and patios common in Irvine villages to avoid demolition, though this adds $2,000-$4,500 to the utility line item.
Brands We Service in Irvine
We specify and coordinate prefab and modular systems from Boxabl, Plant Prefab, and Tuff Shed within our single-contract model, with James Hardie siding stocked locally for site-built finishes. Most brand-specific parts arrive within 3-4 weeks of permit issuance. See our brands for full specifications.
Pricing for ADU in Irvine, CA
| Service | Typical range in Irvine |
|---|---|
| Room-to-ADU conversion | $85,000-$140,000 |
| Above-garage ADU | $110,000-$165,000 |
| Interior JADU | $75,000-$125,000 |
| Electrical panel upgrade | $4,500-$8,500 |
| Plumbing lateral extension | $8,000-$18,000 |
| Gas line extension | $3,500-$7,500 |
| Foundation and grading (detached) | $12,000-$28,000 |
| Landscaping and hardscape restoration | $5,000-$15,000 |
In Irvine, ARC-mandated design matching - specific stucco textures, trim profiles, roof tile - can add $8,000-$15,000 to exterior finishes compared to non-HOA cities. Every project is quoted with a written price before work begins, per Haven Standard Clause 1; the figure you sign is the figure you pay.
Neighborhoods We Serve in Irvine
We design, permit, and build ADUs across Irvine’s village system, from established neighborhoods to newer developments. Scheduling and dispatch are coordinated from our Los Angeles office; crews serve Irvine locally with typical first-site visits within 3-5 business days of call.
- Woodbridge
- Northwood
- Turtle Rock
- Woodbury
- Portola Springs
Service Area - Cities Near Irvine
Our crews work throughout central Orange County, with active projects in Tustin, CA, Santa Ana, CA, Orange, CA, and Newport Beach, CA. Each city has distinct permit timelines and HOA prevalence; we adjust our submittal sequencing 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 About ADU in Irvine
Most Irvine village Architectural Review Committees take 30-60 days for ADU exterior work, with some requiring a second submittal after revision. We prepare the full package - renderings, material samples, landscape plan - before first submission to minimize delays.
No - California AB 670 (2019) prohibits outright bans. However, Irvine’s ARCs can and do enforce reasonable design standards on exterior appearance, which we address in our permit set before city filing.
Yes - we prepare the full permit set, submit to Irvine Community Development, and schedule all inspections through final occupancy. The permit cost is itemized in your written quote, not buried in a contingency line.
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 Irvine Customers Say
"The permit set and the build were one contract with one number. Our neighbours used two firms and spent a year watching them blame each other."
- Helena V."The rental income has covered the payment since the second month. They were realistic about the numbers rather than optimistic."
- Odette N."Handled the whole planning process. We went to one hearing and that was it."
- Rowena C.