A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable Home Addition Contractor Across Irvine
Most Irvine homeowners don’t realize a home addition here rarely starts with a hammer. It starts with two separate approval tracks: the City of Irvine Community Development Department plan check, and, in nearly every master-planned village, a second review by the HOA architectural committee. Miss either one and the project stalls before framing begins. That’s the reality we navigate every week as a Home Addition Contractor serving Irvine, and it’s why we put scoping, pricing, and permit sequencing in writing before anyone signs anything. If you’re weighing a room addition, second story, or garage conversion in Irvine, call (903) 568-7222 and we’ll walk you through what your specific lot and village actually allow.
Why Benson ADU Builders Is Irvine’s Preferred Home Addition Contractor Company
Since 2006, Benson ADU Builders has been part of the Relay Home Co. family, and Troy Eastman has built the Irvine practice around one principle: a written price before work starts, and a written guarantee that outlasts the punch list. Our 365-Day Done Right Promise means if anything isn’t right within a full year of completion, we come back and make it right. No fine print, no phone tag.
Irvine homeowners tend to be detail-driven. They read the CC&Rs, they know their setback from the property line, and they want a contractor who can talk plan check and HOA submittals without blinking. That’s who answers the phone. A live person, 24/7, not a voicemail loop. Our uniformed, background-checked crews show up when we say they will, and every invoice is digital, payable by link, with before-and-after photos logged along the way. When you work with our Home Addition Contractor in Irvine team, you know who’s on your property and exactly where your money is going.
Garage Addition Contractors in Irvine
Garage Addition Contractors in Irvine work with a housing stock that’s unusually uniform: attached two-car and three-car garages built from the 1970s through the 2000s, many in villages like Woodbridge, Westpark, and Northwood. A garage addition typically means either converting the existing garage into conditioned living space or extending it outward for storage, a workshop, or a second home office. In Irvine, the cost typically runs $45,000 to $95,000 for a full garage conversion with a bathroom, depending on whether you need a panel upgrade, slab insulation, or sewer lateral work.
One thing we see often: homeowners assume a garage conversion is a simple interior job. It’s not. Because Irvine’s climate swings from morning marine layer to 90-degree inland heat in the same week, insulation and ventilation details matter more here than in coastal cities. And because many Irvine garages sit at or near the setback line, a conversion that changes the use from parking to habitable space can trigger additional lot-coverage review by the city.
What the work actually involves
First we confirm the existing slab is in good enough shape to build on, then we sequence the city plan check and your village HOA architectural submittal so both reviewers see the same finish details and dimensions. After that it’s framing, MEP rough-in, insulation, drywall, and finishes. The HOA part is the wildcard most contractors won’t mention until it’s too late.
Detached garage conversion vs. attached addition
A detached garage conversion in Irvine often makes more sense as an ADU, since the city’s ADU ordinance allows detached units on most single-family lots, provided you meet setback and height limits. We build with prefab systems from Cover, Dvele, and Boxabl, which compress the framing schedule and give you a fixed product spec before we ever pull permits. That matters in a city where a two-track approval process already eats calendar time.
Bathroom Addition Contractor in Irvine
A Bathroom Addition Contractor in Irvine is usually adding a second or third bath to a 1,500 to 2,200 square foot village home where the original floor plan simply wasn’t designed for it. Think a downstairs half bath off the great room in Woodbridge, or a jack-and-jill between two upstairs bedrooms in a Northwood tract home. A typical bathroom addition in Irvine runs $35,000 to $70,000, with the higher end including slab cutting for sewer lines, a new circuit for a heated floor, and waterproofing that meets current California code.
Irvine homes built in the 1970s and 1980s often have copper supply lines and cast-iron drain lines that look fine until you open the slab. We budget for that on the front end rather than discovering it at demo. That’s the difference between a written price that holds and a verbal estimate that doubles.
Where the cost moves
If your panel is at capacity, adding a bathroom means a 200-amp upgrade, and that’s $4,000 to $7,000 before you pick a tile. If your main sewer lateral has to be extended or replaced, you’re looking at another $6,000 to $12,000 depending on depth and distance to the street. We name these numbers during scoping, not after the drywall is up.
HOA finish requirements
An exterior wall on a bathroom addition means exterior finish changes, and in Irvine villages with active architectural committees, that means a submittal showing the siding or stucco color, window style, and roofline match the existing structure. We’ve done this enough times in places like Turtle Rock and University Park to know exactly which finish specs get approved the first time.
Trusted Brands We Service in Irvine
We build with materials and systems you can research yourself before we ever sign a contract. For Irvine additions, we regularly specify Cover service in Irvine and Dvele for panelized ADU and addition projects, and Boxabl when a client wants a factory-built unit with a predictable price and schedule. We keep local relationships with these manufacturers’ Southern California fulfillment teams, which means faster delivery to Irvine job sites and fewer weeks lost to freight delays. You’re never locked into a single take-it-or-leave-it product. You pick from curated options, backed by our written price and the 365-Day Done Right Promise.
Common Home Addition Contractor Problems We See in Irvine Homes
- HOA submittal treated as an afterthought. In Irvine’s master-planned villages, an unapproved exterior finish or a fence change can trigger a stop-work order. We sequence the HOA architectural review in parallel with city plan check so neither one becomes a late-stage surprise.
- Quoting before the lot constraints are checked. A pre-fab catalog from Abodu, Cover, or Dvele looks great until the setback and lot-coverage math doesn’t work on your specific parcel. We verify height, setback, and coverage against Irvine’s current ADU ordinance before any number goes into a contract.
- Panel and sewer capacity discovered at demolition. Older Irvine homes frequently need a 200-amp upgrade or a new sewer lateral once work begins. We include a structural, MEP, and Title 24 energy check in scoping so those costs are in the written price instead of a change order.
- Underestimating inspection scheduling around village rules. Some Irvine villages restrict parking and staging during certain hours, which affects when our crew can legally deliver materials. We build the inspection schedule around those limits so you’re not paying for a crew that can’t work.
Pricing for Home Addition Contractor in Irvine, CA
Here are honest ranges for Irvine, based on the work we’ve scoped and built in the last several years. A bathroom addition runs $35,000 to $70,000. A garage conversion runs $45,000 to $95,000. A bump-out addition to expand a kitchen or family room runs $60,000 to $130,000. A second story addition on an existing single-story Irvine home starts around $180,000 and can pass $300,000 depending on structural work, stair placement, and roofline integration. Sunroom additions land between $40,000 and $85,000. These are written-price ranges; we don’t do verbal ballparks that drift later. Call (903) 568-7222 and we’ll scope your specific lot, your specific village, and put the number in writing before work starts.
We Also Serve Cities Near Irvine
While this page focuses on Irvine, our crews regularly work in Tustin, Santa Ana, Orange, and Lake Forest. The permit and HOA dynamics shift from city to city, which is why our Home Addition Contractor team scopes every project against the specific jurisdiction. If you’re across the 5 or 405 from Irvine, call (903) 568-7222 and we’ll confirm what applies to your address.
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 Home Addition Contractor in Irvine
Not every addition, but the vast majority in Irvine’s master-planned villages do. City approval comes from the City of Irvine Community Development Department, and if your village has an active architectural committee, any exterior change to siding, roofline, windows, fences, or setbacks typically needs a separate HOA submittal. Interior-only work may skip the HOA step, but exterior work rarely does. Call (903) 568-7222 and we’ll tell you exactly what your village requires before you spend a dollar on drawings.
We start with as-built drawings of your existing home, then run a Title 24 energy calculation, then submit for plan check with the City of Irvine. Once city comments are cleared, we pull the permit. If an HOA applies, we run their architectural submittal in parallel so both approvals land around the same time. Inspections then happen at foundation, framing, MEP rough-in, insulation, and final. The whole sequence for a garage conversion typically runs 4 to 7 months from first drawing to final inspection in Irvine.
In most cases, yes. Irvine’s ADU ordinance allows detached and conversion ADUs on single-family lots, subject to setback, height, lot coverage, and parking rules that vary by village and parcel shape. A detached prefab ADU from Cover or Boxabl often works well on a 5,000 to 6,000 square foot Irvine lot, but it has to clear the same city and HOA reviews as a site-built addition. We’ll tell you what your lot allows before you commit to a product.
The honest answer is that nothing should change the price, because we scope for known Irvine risk factors upfront: panel capacity, sewer lateral condition, slab condition, HOA finish requirements, and village staging restrictions. Where prices move on typical projects is when a homeowner upgrades finishes mid-build or when a hidden condition like rotted framing or inadequate foundation footings surfaces. We cover the common ones in scoping; for the rare unknown, we show you the line item and the cost before we touch it. Call (903) 568-7222 and we’ll put the full scope in writing.
A bathroom addition in Irvine typically takes 8 to 14 weeks. A garage conversion takes 4 to 7 months including the dual city and HOA approval sequence. A second story addition can run 8 to 14 months, with scaffolding and structural phases adding weeks that a simpler bump-out won’t have. We build the calendar from the permit schedule, not from wishful thinking, and we show it to you before we start. Call (903) 568-7222 for a free estimate and a real timeline for your specific project.
In the Woodbridge village area, our crew converted a two-car garage into a detached ADU for a family that needed a full kitchen, bath, and separate entry. The biggest hurdle wasn’t the framing. It was sequencing Irvine’s city plan check alongside the HOA’s architectural submittal so the James Hardie siding color and setback matched what both reviewers would accept. We coordinated the inspection schedule around the village’s parking and staging limits, and the finished unit now functions as a legal, rentable ADU rather than a converted garage. That’s the kind of dual-track coordination that keeps Irvine additions moving when other contractors stall out.
Written by Troy Eastman, Owner at Benson ADU Builders, serving Irvine and surrounding cities since 2006.
