A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Fillmore, CA
Adding an ADU in Fillmore, CA means building on a specific kind of property: lots carved out generations ago, homes with real setbacks, and a Ventura County climate that swings from fog to triple digits. Benson ADU Builders handles the full ADU and home addition process here, from first survey to final inspection, with a written price before any work starts. Troy Eastman runs our Fillmore projects with the same rule every time: no surprises, no verbal estimates that drift, no scope creep. Call (903) 568-7222 and you’ll reach a live person who can talk square footage, setback rules, and ballpark costs on the first call.
Why Fillmore Homes Are Different
Fillmore’s housing stock tilts older, and that changes how we approach every addition. Many homes near Central Avenue and the neighborhoods off Sespe Street were built before modern foundation standards, which means we spend real time on soil and footing work before framing ever starts. The terrain matters too: properties on the east side of town sit closer to the foothills, and grading there can add cost that a flat lot in the valley floor simply doesn’t carry.
Ventura County’s permit office reviews Fillmore ADU applications for setback compliance, fire access, and utility capacity. That’s not a hidden hurdle, it’s a known step we price into your written quote up front. The summer heat also plays a role: stucco and siding details need to go in before the hottest weeks, and we schedule exterior work around those stretches so materials cure properly. None of this is unique to Fillmore in a way that makes the job impossible. It just means the contractor you choose needs to know the town well enough to plan for it.
Fillmore homeowners tend to ask the same three questions: how much, how long, and will the price stay put. Our answers are written down before you sign anything.
Our Main Fillmore Services
Most Fillmore calls to Benson ADU Builders start with one of three projects: a full ADU in the backyard, a home addition that expands the footprint of the main house, or a room addition that turns unused space into something livable. Each has its own page below with local pricing and process details.
ADU Builders in Fillmore
A backyard ADU in Fillmore is typically a detached unit with its own kitchen, bath, and entry, and it’s the most common project we quote for local homeowners who want rental income or a place for family without buying a second property. Fillmore lots vary in depth, which means we spend early time measuring side and rear setbacks before suggesting a floor plan. We build both site-built units and prefab options from the brands homeowners can research themselves. ADU Builders in Fillmore covers pricing, timelines, and what the permit process looks like here.
Home Addition Contractor in Fillmore
A home addition in Fillmore means expanding the existing structure, often to add a primary suite, enlarge a kitchen, or create a great room that opens to the backyard. Older Fillmore homes sometimes have non-standard framing, so we inspect before quoting and include any structural corrections in the written price. Home Addition Contractor in Fillmore breaks down the full scope, from foundation to roof tie-in, with current local pricing.
Room Addition Contractor in Fillmore
A room addition is the smaller sibling: converting a garage, finishing an attic, or adding one bedroom or office without changing the home’s overall layout. Fillmore homeowners use room additions for a dedicated workspace, a nursery, or a quiet guest room, and the permit path is often simpler than a full home addition. Room Addition Contractor in Fillmore explains what counts as a room addition in Ventura County and what to budget.
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 Fillmore
Benson ADU Builders is authorized to build with Cover, Dvele, and Boxabl prefab systems, and we stock the common repair and finish parts for those builds locally, so turnaround on a Fillmore job doesn’t wait on a parts truck from out of state. See our brands for the full list and what each system does best.
Pricing for ADU Company in Fillmore, CA
| Service | Typical range in Fillmore |
|---|---|
| Detached ADU (site-built, 400 – 600 sq ft) | $180,000 – $260,000 |
| Detached ADU (prefab, 400 – 600 sq ft) | $150,000 – $220,000 |
| Garage conversion to ADU | $120,000 – $170,000 |
| Attached JADU (studio, up to 500 sq ft) | $90,000 – $140,000 |
| Home addition (primary suite, 300 – 500 sq ft) | $140,000 – $210,000 |
| Room addition (single bedroom, 150 – 250 sq ft) | $60,000 – $100,000 |
| Room addition (office or studio, 100 – 200 sq ft) | $45,000 – $80,000 |
| Kitchen expansion (200 – 400 sq ft) | $90,000 – $150,000 |
Prices in Fillmore shift most with two things: soil and access. A hillside lot east of town that needs extra grading or a retaining wall will land higher than a flat parcel near downtown. Whatever the number is, it goes in writing before work starts, and it doesn’t change unless you change the scope.
Neighborhoods We Serve in Fillmore
Our crews work throughout Fillmore, from the older lots near downtown up to the newer streets on the east side. We know the setback patterns and terrain differences from one street to the next.
- Central Fillmore (near Central Avenue and Main Street)
- East Fillmore (foothill-adjacent lots off Sespe Street)
- West Fillmore (flat valley parcels near the Santa Clara River)
- North Fillmore (neighborhoods off A Street and B Street)
- South Fillmore (toward the citrus groves and city limit)
Most Fillmore estimates are scheduled within a few business days once you call, and we’ll confirm the exact time before we send a uniformed, background-checked technician to your property.
Service Area – Cities Near Fillmore
Beyond Fillmore, our crews cover the surrounding Ventura County communities. If you’re in Moorpark, CA, Santa Paula, CA, Somis, CA, or Simi Valley, CA, we can scope and quote your ADU or addition the same way: written price, real timeline, no surprises.
Serving Fillmore, CA - Our Local Coverage Area
We’re based in the Fillmore 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 Fillmore
Yes. Benson ADU Builders pulls all required Ventura County and Fillmore city permits, and we handle the inspections too. Your written quote includes permit costs so there’s no line item that appears later.
A prefab ADU in Fillmore generally runs 4 – 7 months from permit approval to final inspection. A site-built unit takes longer, usually 7 – 12 months depending on size, grading, and weather windows on exterior work.
No. The price we write before work starts is the price you pay, unless you ask for a change in scope. Our 365-Day Done Right Promise backs the workmanship in writing for a full year after completion. Call (903) 568-7222 for a free Fillmore estimate.
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 Fillmore 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.
