







A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Thousand Oaks, CA
Adding an ADU in Thousand Oaks means working with real terrain: lots slope in the Conejo Valley, soil conditions shift by neighborhood, and setback rules change based on where your parcel sits. Benson ADU Builders handles the whole process, from first survey to final inspection, so you aren’t juggling three different trades. We build with prefab systems like Cover and Dvele when speed and precision matter, and site-built additions when the lot demands a custom footprint. Call (903) 568-7222 and we’ll walk you through both paths, with a written price before anything gets signed.
Why Thousand Oaks Homes Are Different
Thousand Oaks housing stock skews mid-century and 1980s-90s ranch-style, which means most backyards were graded for a single structure and a pool, not an accessory dwelling. Many lots from Lynn Ranch to Newbury Park border open space or sit on slopes that trigger hillside grading review. That adds time and a structural engineer to the conversation. The summer heat and Santa Ana winds also shape material choice: stucco and fiber cement hold up far better than vinyl siding out here, and we spec James Hardie products on most Thousand Oaks projects for that exact reason. HOA overlays in communities like Wildwood and Sunset Hills can restrict ADU height, colors, and even where a driveway can punch through. We pull every permit with the City of Thousand Oaks and Ventura County, and we don’t start digging until the paperwork clears. That’s the only way to keep a Thousand Oaks job honest.
Our Main Thousand Oaks Services
Thousand Oaks homeowners call us most about three projects: a standalone backyard ADU, an attached home addition, or a single room bump-out that turns a cramped floor plan into something livable.
ADU Builders in Thousand Oaks
A detached ADU in Thousand Oaks typically requires a separate structure, new utility runs, and compliance with the city’s floor area and setback rules. We survey the lot first, confirm what the zoning allows, then show you prefab options from Dvele, Cover, and Mighty Buildings alongside a traditional site-built estimate. You choose based on schedule, budget, and how the unit needs to function. Learn more about how we approach ADU Builders in Thousand Oaks, including what fits under the 800-square-foot city allowance.

Home Addition Contractor in Thousand Oaks
A full home addition means tying new framing and roofline into the existing structure without making the original house look bolted-on. On the sloping lots east of the 23 freeway or the flatter parcels near Westlake Boulevard, we engineer the foundation and drainage first, then match the cladding and roof pitch. You get one crew, one schedule, and one written price instead of a loose collection of subs. See how we run projects end to end on our Home Addition Contractor in Thousand Oaks page.

Room Addition Contractor in Thousand Oaks
One extra room changes the whole flow of a ranch-style Thousand Oaks house. We’ve converted spare side yards into bedrooms, carved offices out of garage-adjacent space, and pushed kitchens out toward back patios with a bump-out framed to match the original 1970s vaulted ceilings. Site access dictates how we stage materials, and on tight Thousand Oaks lots, that means careful sequencing with the neighbors in mind. Details on timelines, permits, and cost examples are on the Room Addition Contractor in Thousand Oaks page.

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.
Brands We Service in Thousand Oaks
Where a Thousand Oaks ADU calls for a prefab, we build with Cover, Dvele, Mighty Buildings, and Boxabl systems. Where it calls for cladding, we use James Hardie siding and trim. See the full range on our brands page, then ask which system fits your lot.
Pricing for ADU Company in Thousand Oaks, CA
| Service | Typical range in Thousand Oaks |
|---|---|
| Prefab ADU (Cover or Dvele, 400-800 sq ft) | $180,000 – $320,000 |
| Detached site-built ADU (studio, 400-600 sq ft) | $160,000 – $260,000 |
| Detached site-built ADU (2-bed, 600-800 sq ft) | $210,000 – $350,000 |
| Garage conversion to ADU | $95,000 – $170,000 |
| Attached ADU (converted rear wing or new addition) | $140,000 – $240,000 |
| Home addition (single room, 300-500 sq ft, full finish) | $110,000 – $190,000 |
| Room addition (bedroom with closet and window, no bath) | $85,000 – $145,000 |
| Room addition (primary suite with bath) | $135,000 – $220,000 |
| Site prep, grading, and foundation on sloped lots | $18,000 – $50,000 |
| Utility runs and hookups (water, sewer, electric, gas) | $12,000 – $40,000 |
Slope is the fastest way to push a Thousand Oaks budget up: steep lots need retaining walls and extra foundation piering, and those aren’t optional. We give you a written line-item price before any work starts, so the cost you approve is the cost you pay.
Neighborhoods We Serve in Thousand Oaks
Benson ADU Builders runs projects all over Thousand Oaks, from flat-lot neighborhoods near the 101 to hillside parcels that need engineered foundations. We coordinate parking and staging with the neighbors and keep material deliveries tight so the street stays clear.
- Newbury Park
- Lynn Ranch
- Wildwood
- Sunset Hills
- Dos Vientos
Service Area – Cities Near Thousand Oaks
Beyond Thousand Oaks, our crews cover the Conejo Valley and adjacent communities. We also regularly work in Westlake Village, CA, Oak Park, CA, Newbury Park, CA, and Agoura Hills, CA. Same written-price guarantee and the same live-person phone line on every job.
Serving Thousand Oaks, CA - Our Local Coverage Area
We’re based in the Thousand Oaks 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 Company in Thousand Oaks

We typically begin site surveying and design work within one to two weeks of your signed estimate. Permits through the City of Thousand Oaks add their own timeline depending on the project scope, slope review, and any HOA requirements. Call (903) 568-7222 and we’ll give you an honest calendar read.
Yes in some communities. HOAs like Wildwood and Sunset Hills can set rules on ADU height, setback, color, and driveway placement that go beyond city zoning. We pull HOA design guidelines before the first drawing so the plan clears both the association and the city.
If any work we performed isn’t right within a full year after completion, Troy Eastman and the Benson team make it right. The promise is stamped on your written guarantee, and every project also includes a free second visit if a covered repair fails.
No. You receive a written price before any work begins, and we don’t bill for surprises at the door. If a slope or soil condition requires a change, we put the revised number in writing before anything is modified. Call (903) 568-7222 for a free estimate.
Call Benson ADU Builders at (903) 568-7222 and tell us about your Thousand Oaks lot. We’ll give you a straight answer on what’s possible, what it costs, and how long it takes. A live person answers, day or night, and your written price comes before any work starts.
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 Thousand Oaks Customers Say
"Booked a consult online and met the project manager two days later. Weekly progress updates arrived by text with photos. ADU finished on schedule."
- Hannah W."Clean, quiet crew. They respected the neighbors, kept noise to working hours, and swept the driveway every evening."
- Hope C."Communication was the best part. I always knew what was happening that week without having to ask."
- Dolly N.



