Fast, Reliable ADU Builders Across Arcadia
If you’re planning a detached ADU or garage conversion in Arcadia, the big question is usually what it will actually cost once walls are opened and the older wiring, framing, and waterproofing show themselves. A full detached ADU in Arcadia typically runs $250,000 – $420,000 depending on square footage, foundation conditions, and whether the structure must mirror a high-end primary home’s architecture. Call (254) 602-5618 and we’ll walk your lot, look at what’s behind the walls, and put a written price in your hands before any work starts.
We’re led by Russ Delmar, and our crews work Arcadia neighborhoods every week, from the Upper Arcadia estate lots near the foothills to the 1950s ranch tracts south of Huntington Drive. When you call about an ADU, you get a live person. When we quote, you get a number in writing. When we build, the price stays where we said it would, unless you approve a change in writing first.
Why Lodgewick ADU Builders Is Arcadia’s Preferred ADU Builders Company
The Kingswell family has run home-service companies since 2010, and our ADU business operates under The Kingswell Guarantee. That means four things on every Arcadia project: a written price before work begins, a real arrival window, a clean job site at the end of each day, and a written guarantee that lasts a full 365 days. If something isn’t done right within that year, we come back and make it right, at no charge. That’s the 365-Day Done Right Promise, and it’s printed on every contract.
Arcadia homeowners tend to be detail-oriented. Many have been through remodels before, and a lot of them have seen quotes move after demo. Our approach is built for that: inspection findings are priced and approved in writing before we touch anything, and allowance line items are written into the contract from day one so a hidden aluminum wiring run or a termite-damaged stud doesn’t become a fight.
Our technicians are background-checked and uniformed. You’ll know exactly who is on your property. When you call with a question at 9 p.m. about your build or your guarantee, a live person answers, not a voicemail loop. That’s how we operate across ADU Builders projects, and it’s how we run every job in Arcadia.
Detached ADU in Arcadia
A Detached ADU in Arcadia is a fully independent living structure built in the rear yard of a single-family lot, with its own kitchen, bathroom, bedroom, and private entry, and on most Upper Arcadia parcels there is genuinely enough room to do it well. These are the projects Arcadia homeowners call about most, and they’re rarely simple studio boxes. On the 15,000 to 25,000-square-foot lots below the San Gabriel foothills, a detached ADU typically becomes a two-bedroom family compound structure sized for grandparents, running $280,000 – $420,000 depending on finish level and whether it has to mirror a newly built or extensively remodeled main home.
One thing that separates Arcadia from nearby Monrovia or El Monte is the design standard: the city requires ADUs to match the architectural character of the primary residence. Roofline pitch, facade materials, window articulation. A rear-yard ADU behind a Mediterranean spec home needs those elements echoed, and that adds design and framing cost a first-time bidder from outside Arcadia routinely misses.
Foundation and Site Work
Many Arcadia backyards slope gently toward the street as the land falls away from the alluvial fan. We handle grading, drainage, and foundation work with that slope in mind, because a detached ADU that sits too low will hold water in winter storms and cost you in repairs later. Pier and grade-beam systems are common here, and we size them for the soil conditions we’ve actually seen on Arcadia lots, not a generic spec.
Matching the Main House
When your primary home was built or rebuilt in the last twenty years with a Spanish tile roof and arched window heads, your ADU has to follow. We take roof pitch measurements, match exterior finish materials, and detail window trim to the same articulation as the main house. That costs more than a flat-roof box, and we tell you that in the first written estimate, not after framing starts.
JADU in Arcadia
A JADU in Arcadia is a Junior Accessory Dwelling Unit, a smaller unit of 500 square feet or less created within the existing footprint of a single-family home, often by converting a garage, a rear bedroom and bath, or an oversized mudroom into an independent living space with its own small kitchen and separate entry. It’s the lower-cost path for families who need a private space for an aging parent but don’t want to build a separate structure. In Arcadia, a JADU conversion typically runs $120,000 – $180,000, depending on the plumbing stack locations, electrical panel capacity, and what we find inside the walls of a 1950s or 1960s home.
Because JADUs live inside the existing structure, they’re where hidden conditions show up fastest. Older Arcadia homes can hide aluminum branch wiring, undersized floor joists, and failed waterproofing. Our written estimate includes inspection line items and allowances for exactly these conditions, so when we open a wall and find something, you’ll see the upgrade priced and approved in writing before we proceed.
Garage Conversion JADUs
Oversized two-car and three-car garages are common on Arcadia’s estate-scale lots, and a garage JADU keeps the structure’s shell while rebuilding the interior as a living space. We add insulation, run new electrical, level and seal the slab, and install a kitchenette and bath. The permit triggers current energy code requirements, and we build those into the written scope from the start, not as a surprise line item.
Attached Home-Space JADUs
When the conversion uses an existing rear bedroom and bath, we’re usually removing a wall or two and reconfiguring plumbing within the existing footprint. These projects move faster because the shell and roof are already there, but the same older-wiring and framing risks apply. We document what we find, price it in writing, and get your approval before changing anything.
Trusted Brands We Service in Arcadia
Arcadia homeowners sometimes want a detached ADU built as a site-framed custom structure, and other times they want a factory-built prefab unit placed on their lot. We work with both, and we’re familiar with Abodu, Cover, and Dvele as established prefab ADU lines that hold up well on California lots. When a homeowner chooses a prefab module, we handle the site work, foundation, utility connections, and all permit work around it, and we coordinate directly with the manufacturer so the unit arrives on schedule. For Arcadia clients, we stock common connection parts locally so a missing fitting doesn’t stall the job for days.
Common ADU Builders Problems We See in Arcadia Homes
- Hidden aluminum branch wiring in 1950s and 1960s tract homes. Many Arcadia houses south of Huntington were built in that era, and aluminum wiring surfaces once drywall comes down. It must be remediated to meet current electrical code, and a quote that didn’t plan for it becomes a change-order fight. Ours does plan for it.
- Design-standard mismatches on detached ADUs. Arcadia requires a rear-yard ADU to mirror the primary home’s roofline, facade materials, and window articulation. Contractors from neighboring cities routinely miss the design review cost and the added framing complexity. We bid it correctly the first time.
- Undersized HVAC for structures without the main home’s thermal mass. Detached ADUs heat up fast in Arcadia’s 100°F+ summer days. We size systems for the actual heat load on your specific lot, not a rule-of-thumb tonnage.
- Fire hazard zone requirements in the Highlands. Some upper residential streets in Arcadia sit in elevated fire hazard severity zones, which triggers Class A roofing and ember-resistant vent requirements even on rear-yard structures. We know which parcels this applies to and build it into the written scope.
Pricing for ADU Builders in Arcadia, CA
A garage conversion JADU in Arcadia typically runs $120,000 – $180,000. A detached studio ADU starts around $220,000 – $260,000, and a full two-bedroom detached family ADU that matches a high-end main home runs $280,000 – $420,000. The three biggest cost drivers here are the size of the structure, whether Arcadia’s design standard forces architectural matching with the primary home, and what’s behind the walls of an older home when we open them. Our written estimate includes allowance line items for electrical, framing, and waterproofing conditions we commonly find in Arcadia’s housing stock, so you’ll see the range before we start, and any actual finding gets priced and approved in writing before we touch it. Call (254) 602-5618 for a free estimate on your specific lot.
We Also Serve Cities Near Arcadia
Our crews regularly work Monrovia, Temple City, Sierra Madre, and San Gabriel, and we keep the same written-price rule on every job. If you’re in a neighboring city and planning an ADU, the process starts the same way: an inspection, a written scope, and a number that doesn’t move unless you approve a change in writing. Call (254) 602-5618 and ask for Russ Delmar’s team.
Serving Arcadia, CA - Our Local Coverage Area
We’re based in the Arcadia 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 Builders in Arcadia
Because Arcadia’s core housing stock is 1950s – 1970s ranch and traditional homes, and many still contain aluminum branch wiring, undersized framing, or failed waterproofing behind the drywall. Contractors who bid before opening the walls discover these conditions after demo and hit you with change orders. We write inspection and allowance line items into your contract from day one, document everything we find, and get your written approval on any upgrade before proceeding. You’ll know the cost before work restarts. Call (254) 602-5618 for a written estimate that plans for this.
Yes. Arcadia’s design standards require a detached ADU to match the architectural character of the primary residence, including roofline pitch, facade materials, and window articulation. That adds design and framing cost to any rear-yard ADU, and it’s the single most common thing out-of-area contractors underestimate on their first Arcadia bid. We’ve built enough of these to price it correctly up front.
Some do. Properties in the upper residential streets of the Highlands and other foothill-interface areas of Arcadia sit in elevated fire hazard severity zones. That triggers Class A roofing material requirements and ember-resistant vent covers even for rear-yard ADUs. We check your parcel’s designation as part of the initial site review and include any required materials in the written scope. Call (254) 602-5618 if you want us to check your address.
Expect a full-featured structure, not a studio. Arcadia’s ADU demand is largely driven by multigenerational families building for grandparents, so we typically design a two-bedroom unit with a private entry, separate kitchen, full bath, and living quarters sized for elder comfort, not rental efficiency. Single-story floor plans, wider doorways, and step-free entries are standard on these projects. A private-entry arrangement also matters here: family members need to come and go without walking through the main house. We’ll design for that and price it in writing before you commit.
Yes, and Arcadia’s estate-scale lots often have oversized two- and three-car garages that convert well into JADUs or full garage-conversion ADUs. A garage JADU keeps the existing shell, while a full conversion may remove it entirely depending on condition and what’s under the slab. The permit will trigger current energy code upgrades, including insulation and possibly panel work, and we price those into the written estimate from the beginning. Call (254) 602-5618 for a free site review.
Written by Russ Delmar, Owner at Lodgewick ADU Builders, serving Arcadia and the surrounding San Gabriel Valley communities.