







A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable ADU Builders Across Oxnard
Most Oxnard homeowners call us because they want a straight answer: what will this actually cost, and when can it start. A detached ADU in Oxnard typically runs $180,000 – $320,000 depending on size, site conditions, and finish level. A JADU converted from an attached garage usually lands between $90,000 and $160,000. Those aren’t statewide ballparks. They reflect what we see on the ground here, where expansive clay soils, salt air, and Oxnard’s strict wind load requirements shape every foundation and fastener decision. If you’re weighing options on your lot, call (831) 230-7250. We’ll walk the property, check the soils, and give you a written price before you commit to anything.
Why Lodgewick ADU Ventura Is Oxnard’s Preferred ADU Builders Company

Lodgewick ADU Ventura is part of the Kingswell family of home-service companies, established in 2010. Russ Delmar leads our Oxnard work, and he’s walked enough lots from the Southwinds neighborhood to the homes near Channel Islands Harbor to know the difference between a clean build and one that will fight the coastal air for decades. Our ADU Builders team has built detached units, garage conversions, and junior ADUs across Oxnard, and we’ve seen the same pattern repeat: homeowners who got generic California quotes, then discovered their Oxnard lot needed a soils report, stainless hardware, and uplift strapping that no one priced in.
We don’t work that way. Every project starts with a written price. Every project ends with a written guarantee: our 365-Day Done Right Promise. If something isn’t right within a year, we come back and make it right, free. That’s not a slogan. It’s on paper, signed, before we drive the first stake.
We also answer the phone. A live person, 24 hours a day, seven days a week. No voicemail loops, no chat bots. When you call about your Oxnard ADU, you talk to someone who knows what’s happening on your permit, your foundation, and your schedule.
Detached ADU in Oxnard
A Detached ADU in Oxnard is a separate living unit built in your backyard, usually 400 to 800 square feet, with its own entrance, kitchen, bath, and often its own address. It’s the choice for homeowners on the Oxnard Plain who have a deep lot and want rental income or a private space for family without sharing walls. Detached ADUs here cost more than garage conversions because they need new foundations, new utility runs, and full plan check review. Oxnard’s expansive clay soils mean most sites need a geotechnical report first. That report drives the foundation design, and skipping it is the fastest way to blow a budget.
Site Prep and Foundation Work
Before framing, we typically remove sod, grade the pad, and dig footings deep enough to reach stable soil below the expansive clay layer common across Oxnard. Some lots near the coast also need corrosion-resistant rebar coatings. We pull the soils report, engineer the footings, and submit for the city’s plan check. This phase runs $15,000 – $38,000 depending on lot conditions, and it’s where generic builders underbid.
Framing, Envelope, and Finishes
Once the foundation passes inspection, framing moves fast. We use uplift strapping rated for Oxnard’s coastal wind exposure. Roof fasteners are stainless steel, not galvanized, because salt air near the harbor and beaches will rust standard hardware within a year or two. Interior finishes, electrical, plumbing, and HVAC typically bring the total to $180,000 – $320,000 for a completed unit ready to rent or occupy.
JADU in Oxnard

A JADU in Oxnard, or junior accessory dwelling unit, converts space inside an existing home, most often an attached garage, into a compact living unit under 500 square feet. It shares the main house’s lot but gets its own entrance, a kitchenette, and a separate bath. JADUs cost $90,000 – $160,000 in Oxnard because you’re reworking an existing structure rather than building new. That savings comes with a caveat: Oxnard’s coastal wind and corrosion requirements still apply to any new openings, any exterior hardware, and any structural upgrades to the existing garage.
Garage Conversion Reality in Oxnard
Many 1950s and 1960s era homes in Oxnard have attached garages with slab floors that were never engineered for living space. We check the slab thickness, the wall anchorage to the foundation, and the roof diaphragm before quoting. If the slab is too thin or unpermitted additions exist, your JADU price moves up. A straight garage conversion with good bones runs $90,000 – $130,000.
Utility Runs and Compliance
Every JADU needs its own electrical subpanel in Oxnard, and older homes often need a service upgrade to carry the additional load. Water and sewer tie-ins vary by lot. If the main house sits far from the sewer lateral or the water meter is undersized, expect $8,000 – $18,000 in utility work beyond the base conversion. We price all of it in writing before work starts.
Trusted Brands We Service in Oxnard
We work with leading ADU manufacturers and material suppliers, matched to your lot, budget, and timeline. For Oxnard’s wind and corrosion environment, we often spec Cover panels for their factory-sealed exterior assemblies, Dvele for high-performance modular units that hold up in salt air, and Mighty Buildings for panelized systems that install quickly once the foundation is done. These aren’t off-the-shelf kits we hope will fit. We order to your site plan and coordinate delivery so materials arrive when your Oxnard foundation has passed inspection and not a week before. Fast turnaround on parts and panels keeps your permit schedule intact.
Common ADU Builders Problems We See in Oxnard Homes
- Under-budgeted foundations. A builder quotes standard footings, then hits Oxnard’s expansive clay and suddenly needs a soil report plus deeper excavation. Your $22,000 foundation becomes $40,000. We include the soils report in our written price from day one.
- Coastal corrosion on standard hardware. Homes within a couple miles of the beach or Channel Islands Harbor see galvanized fasteners rust in under a year. We spec stainless steel for all exterior connections, which costs more up front and lasts decades.
- Plan check rejections over wind loads. Oxnard enforces specific upward-lift requirements for accessory structures. A missed detail here sends your permit back for corrections, adding weeks. We’ve worked the city’s plan check enough to submit right the first time.
- Old garages that won’t pass inspection. Unpermitted prior work, cracked slabs, and missing anchorage fail inspection on JADU conversions. We identify these during the estimate, not after the walls are open.
Pricing for ADU Builders in Oxnard, CA
Here’s what we quote, in writing, for Oxnard specifically. A detached ADU runs $180,000 – $320,000. A JADU from an attached garage runs $90,000 – $160,000. Soil reports add $3,500 – $7,000 on detached builds. Deeper footings for expansive clay add $10,000 – $28,000. Service upgrades run $4,000 – $9,000 when your existing panel can’t carry the new load. Stainless steel exterior hardware adds $3,000 – $8,000 compared to standard galvanized. Those are real numbers from real Oxnard builds. We don’t change them at the door. Call (831) 230-7250 and we’ll give you a line-item quote for your specific lot, free.
We Also Serve Cities Near Oxnard
Our crews cover Oxnard and the surrounding area, including Port Hueneme, Camarillo, Somis, and Santa Paula. Many of our Oxnard clients also own rental property nearby, and we handle ADU builds across the county line with the same written pricing and 365-Day Done Right Promise. If you’re in Oxnard or a neighboring city, ADU Builders in Oxnard is where you’ll find us working week to week.
Serving Oxnard, CA - Our Local Coverage Area
We’re based in the Oxnard 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 Oxnard
Yes, in most cases. Oxnard’s expansive clay soils shift with moisture, and the city generally requires a geotechnical report before approving a detached ADU foundation. The report runs $3,500 – $7,000 and typically saves far more by getting the footing depth and reinforcement right before concrete pours. Call (831) 230-7250 and we’ll confirm whether your specific lot triggers the requirement.
Plan for 10 to 14 months. Soils report and foundation engineering run 3 to 6 weeks. City plan check in Oxnard typically takes 6 to 10 weeks, longer if wind load details are incomplete. Construction runs 5 to 8 months depending on finishes. We schedule every phase and keep you updated through the process. Call (831) 230-7250 for a build calendar specific to your lot.
Usually yes, if the garage has an adequate slab, proper wall anchorage, and no major unpermitted work. Oxnard allows JADUs up to 500 square feet within the existing footprint. Some coastal-adjacent garages need extra structural upgrades for wind uplift. We’ll inspect and tell you exactly what your garage needs before we quote, in writing. Call (831) 230-7250 to schedule a walkthrough.
Foundation surprises. If you skip the soils report and hit expansive clay mid-dig, your footing costs can rise $10,000 – $28,000 with no warning. That’s why our written price always includes the report and engineered footings up front. The second cost driver is service panel upgrades. Older Oxnard homes often need a panel replacement to feed the ADU, adding $4,000 – $9,000. We identify that during the estimate, not after drywall goes up. Call (831) 230-7250 for a quote that covers these items before work begins.
No separate water meter is required for most ADUs in Oxnard. You may share the existing meter as long as the service line has enough capacity. However, many older homes in Oxnard have undersized laterals, and we sometimes install a larger line or add a sub-meter for tenant billing. We’ll check your service size and meter capacity during the estimate. Call (831) 230-7250 and we’ll confirm what your lot needs.
Last spring our crew built a 500-square-foot detached ADU off a 1950s bungalow in the Southwinds neighborhood. We upgraded the roof uplift strapping to meet Oxnard’s wind exposure for the coast, swapped standard roof fasteners for stainless steel due to salt air, and worked with the city’s plan check to get the foundation engineered for the local expansive clay, keeping the project on schedule and under the owner’s target budget. That’s the standard we bring to every Oxnard build.
Ready to get a real number? Call (831) 230-7250 now. You’ll reach a live person who can answer questions about your Oxnard lot and schedule a free estimate. We’ll provide a written price before any work starts, and the 365-Day Done Right Promise in writing on every project. That’s The Kingswell Way: a small house on your larger property, built right, priced honestly, and guaranteed.
Written by Russ Delmar, Owner at Lodgewick ADU Ventura, serving Oxnard since 2010.




