







A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Somis, CA
Benson ADU Builders is the ADU company Somis homeowners call when they want a real price in writing before any dirt moves. Adding an ADU, home addition, or room addition in Somis works differently than it does in Oxnard or Thousand Oaks because the lots are larger, the setbacks are more forgiving on agricultural parcels, and the older ranch-style stock gives us room to work. Call (903) 568-7222 for a free estimate on any project in Somis.
Why Somis Homes Are Different

Somis sits at the eastern edge of Ventura County, tucked between Camarillo and Moorpark, where residential streets fade into lemon groves and horse ranches. That agricultural zoning shapes almost every ADU project we price here. Many Somis lots are a half acre or more, which means detached ADUs usually clear the standard rear and side setback requirements without a variance. But older parcels in Somis were platted before today’s stormwater rules, so grading and drainage corrections show up in more estimates than you’d see on a tight suburban lot in Camarillo.
The building stock is older ranch homes, mostly built between the 1950s and 1980s, with a few newer custom builds mixed in along North and West Streets. Those older homes frequently need panel upgrades before we can feed a new ADU subpanel, and several Somis streets are on septic rather than sewer, which affects how Ventura County Environmental Health reviews the project. Santee Avenue and the roads branching off Somis Road tend to be the flat, build-friendly parcels; the hillside lots up toward the Santa Monica Mountains need extra pier work and sometimes a soils report before we can quote foundation costs. If the home has an HOA, we review the CC&Rs early so the design package matches what the board will actually sign off on.
Our Main Somis Services
Most Somis homeowners reach out for one of three projects, and each has its own dedicated Somis page with full pricing and details:
ADU Builders in Somis
A detached ADU on a Somis acre is often the cleanest permitting path we see, because the zoning already allows an accessory unit on most agricultural and residential lots. We price both prefab and site-built options, and for Somis clients we walk through how Cover and Dvele models handle the county’s fire-hardening requirements for wildland-adjacent zones. Detached units on larger lots rarely trigger the neighbor-notification friction you’d find on a dense Ventura street. ADU Builders in Somis

Home Addition Contractor in Somis
Because so many Somis homes sit on oversized lots, we’re often adding a primary suite or a great-room wing to the back of a ranch house rather than bumping toward the side lot lines. The older single-story homes in Somis are good candidates for a gable-end addition that ties into the existing truss profile, and we always check the septic layout before setting the foundation line. We handle the full set: foundation, framing, roof tie-in, electrical and plumbing through a dedicated home addition permit with Ventura County. Home Addition Contractor in Somis

Room Addition Contractor in Somis
A single-room bump-out in Somis, like a larger kitchen or a home office with a view toward the orchards, is usually a spot-zoned permit that avoids a full plan check, which keeps the pre-construction phase shorter. We quote the whole job, including drywall, paint, flooring, and the patch-in where the new roof meets the old one. Somis homeowners working from home call about this one most when they want a dedicated office with a separate entrance. Room Addition Contractor in Somis

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 Somis
We build with Dvele, Boxabl, and Mighty Buildings in Somis, and we service every unit we install. Parts for these systems are ordered from the manufacturer and staged at our dispatch hub before the crew rolls, so Somis installs don’t stall waiting on a panel shipment. See our brands for the full line.
Pricing for ADU Company in Somis, CA
Below are the ballpark ranges we quote for Somis work today. These include our written-price guarantee, meaning the number on your estimate is the number on the invoice, unless you change the scope yourself.
| Service | Typical range in Somis |
|---|---|
| Detached one-bedroom ADU (prefab, base spec) | $180,000 – $260,000 |
| Detached one-bedroom ADU (site-built) | $220,000 – $320,000 |
| Detached two-bedroom ADU (prefab, base spec) | $260,000 – $380,000 |
| Detached two-bedroom ADU (site-built) | $300,000 – $450,000 |
| Garage conversion to ADU | $110,000 – $190,000 |
| Home addition, 300 to 600 square feet | $120,000 – $260,000 |
| Home addition, 600 to 1,200 square feet | $240,000 – $480,000 |
| Primary suite addition | $150,000 – $300,000 |
| Bathroom addition (non-primary) | $55,000 – $110,000 |
| Room addition, single room | $60,000 – $140,000 |
| Kitchen expansion bump-out | $80,000 – $160,000 |
| Septic expansion or tie-in work (where required) | $15,000 – $40,000 |
The two things that push Somis prices to the top of these ranges are septic-related upgrades and hillside foundation work. Both get caught in the estimating phase, not after demolition starts. Troy Eastman makes sure every Somis quote includes a written price before any work begins, so there’s no “we found a problem” add-on later.
Neighborhoods We Serve in Somis
We cover all of Somis, including the ranch parcels that don’t show up on a standard city map. Most of our Somis crews can be on site within one business day for an initial walk-through.
- Somis Road corridor
- North and West Street area
- Santee Avenue and surrounding ranch parcels
- Mesa Drive and the hillside lots below the Santa Monica ridgeline
- Lemon Grove and Bradley Road area
Service Area – Cities Near Somis
While this page covers Somis specifically, our crews also cover the surrounding towns for ADU and addition work. That includes Camarillo, CA, Santa Paula, CA, Moorpark, CA, and Newbury Park, CA. If you’re on the edge of Somis and cross into an adjacent town, we can typically schedule the same crew.
Serving Somis, CA - Our Local Coverage Area
We’re based in the Somis 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 Somis

Most Somis walk-throughs get scheduled within one business day. Scheduling is coordinated from our Los Angeles office, with crews based locally for Somis work. Call (903) 568-7222 and a live person picks up.
Somis is unincorporated Ventura County territory, so residential building permits go through Ventura County, not a city hall. Septic parcels also need a sign-off from the county’s Environmental Health division. We handle both tracks and include permit fees in our written estimate, so there’s no surprise line item.
Yes. The price on your written estimate from Benson ADU Builders is fixed unless you change the scope. That’s the point of our no-hassle upfront pricing, and it’s stamped on the 365-Day Done Right Promise that covers every Somis project for a full year. If you want to see it in writing before committing, call (903) 568-7222 and ask for the line-item quote.
For a free estimate on an ADU, home addition, or room addition in Somis, call Benson ADU Builders at (903) 568-7222 and ask for Troy. Written price first, every time.
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 Somis 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.



