A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in West Hills, CA
Adding an ADU in West Hills usually costs between $180,000 and $420,000 depending on whether you go prefab, garage-conversion, or site-built, and the big local variables are fire-zone requirements, hillside grading, and the age of your existing structure. Benson ADU Builders handles all of it with a written price before any work starts, so you’ll never get a surprise change order when the shovel drops. Call (559) 282-2291 for a free estimate.
Why West Hills Homes Are Different
West Hills is the hotter, hillier western edge of the San Fernando Valley, and that changes how we build. Summer temperatures regularly clear 100°F, so any ADU here needs better insulation and higher-efficiency cooling than a comparable unit in, say, the coastal basin. We specify R-38 or better ceiling insulation, low-E dual-pane glass, and mini-split or ducted heat pumps sized for triple-digit afternoons, not just July averages. The area also sits in a Very High Fire Hazard Severity Zone, which means ember-resistant vents, Class A roof assemblies, and defensible-space setbacks are baked into every design from day one, not bolted on after a plan-check rejection.
The housing stock leans heavily toward mid-century ranch homes and 1970s-80s single-story builds on oversized lots, many with detached garages and deep rear yards in the foothills north of Roscoe Boulevard. That’s why detached ADUs and garage conversions dominate the West Hills market. Homeowners here often have 8,000 to 15,000 square-foot lots, but the challenge comes on hillside parcels north of Victory Boulevard, where the Hillside Ordinance tightens height and grading limits. On those sites, we frequently shift to split-level or stepped foundation designs to stay within the rules while preserving usable square footage.
Our Main West Hills Services
Most West Hills homeowners reach out about one of three things: building a new detached ADU, expanding the footprint of the main house, or converting underused space into a properly permitted room. Each service has its own West Hills page with full pricing, timelines, and project examples.
ADU Builders in West Hills
Detached ADUs and garage conversions are the most common project type in West Hills, and for good reason. The lots are big, the rear yards are deep, and the updated accessory dwelling unit ordinance makes adding a rental unit or multigenerational suite more feasible than ever. Prefab options from ADU Builders in West Hills can cut construction time by months, while site-built units let you match the architectural character of an existing ranch home. On hillside lots, we handle the grading and foundation engineering that standard flat-lot builders often overlook.
Home Addition Contractor in West Hills
A home addition in West Hills means tying new rooflines into mid-century ranch framing, which is usually straightforward but sometimes reveals 50-year-old foundation settling that needs addressing first. We price the full scope up front, including engineering, shear wall upgrades, and fire-zone compliance, so the number you approve is the number you pay. See Home Addition Contractor in West Hills for the full breakdown.
Room Addition Contractor in West Hills
A single room addition, whether it’s a primary suite, home office, or expanded kitchen, is the fastest way to add square footage without a full remodel. In West Hills, we pay close attention to window orientation on west-facing walls, where afternoon heat gain is brutal from June through September. Room Addition Contractor in West Hills covers what a room addition costs, how long it takes, and what permits you’ll need.
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 West Hills
We’re authorized to build with Abodu, Cover, Dvele, and Mighty Buildings, which means you get a curated set of vetted, independently researchable ADU products instead of one take-it-or-leave-it option. See our brands for the full list and what each one does best.
Pricing for ADU Company in West Hills, CA
| Service | Typical Range in West Hills |
|---|---|
| Detached ADU (prefab, 1 bed / 1 bath) | $180,000 – $280,000 |
| Detached ADU (site-built, 1 bed / 1 bath) | $220,000 – $340,000 |
| Detached ADU (site-built, 2 bed / 2 bath) | $280,000 – $420,000 |
| Garage conversion to ADU | $140,000 – $220,000 |
| JADU (junior ADU, attached) | $90,000 – $150,000 |
| Home addition (primary suite, 400 sq ft) | $180,000 – $260,000 |
| Home addition (kitchen expansion) | $140,000 – $220,000 |
| Room addition (single room, 200 sq ft) | $80,000 – $130,000 |
| Room addition (home office) | $60,000 – $100,000 |
Hillside lots north of Victory Boulevard will push prices toward the top of these ranges because grading, retaining walls, and stepped foundations add real cost. Fire-zone requirements like ember-resistant vents and Class A materials also add a few thousand dollars that flatland builders don’t always quote. Whatever your project, Benson ADU Builders puts a written price in your hands before any work starts, and that number doesn’t move unless you change the scope.
Neighborhoods We Serve in West Hills
We work across all of West Hills, from the equestrian-zoned streets near Fallbrook Mall up into the hillside neighborhoods off Valley Circle Boulevard. Response time for estimates anywhere in the city is typically within 48 hours.
- Foothill estates north of Roscoe Boulevard
- Hillside parcels off Valley Circle Boulevard
- Neighborhoods around Welby Way and Platt Avenue
- Areas near Shadow Ranch Park
- Streets bordering El Camino Charter High School
Service Area – Cities Near West Hills
Benson ADU Builders also serves homeowners in the surrounding San Fernando Valley communities. If you’re in Canoga Park, CA, Woodland Hills, CA, Winnetka, CA, or Calabasas, CA, the same written-price guarantee and 365-Day Done Right Promise apply. Scheduling is coordinated from our Los Angeles office, and crews serve West Hills locally.
Serving West Hills, CA - Our Local Coverage Area
We’re based in the West Hills 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 West Hills
We typically schedule West Hills estimates within 48 hours of your call. The site visit takes about an hour, and you’ll receive a written line-item price afterward, not a verbal ballpark. Call (559) 282-2291 to book yours.
Yes. Because West Hills sits in a Very High Fire Hazard Severity Zone, your ADU plans must include ember-resistant vents, Class A roofing, and defensible-space clearances. We handle all of that in the design phase and pull every permit ourselves.
We do. Hillside parcels north of Victory Boulevard fall under the Hillside Ordinance, which limits height and grading. We will design around those limits rather than fight them, often using split-level or stepped foundations to maximize buildable square footage. Call (559) 282-2291 to discuss your specific lot.
Ready to talk numbers? Call (559) 282-2291 for a free, no-pressure estimate on your West Hills ADU, home addition, or room addition. You’ll get a written price before any work starts, backed by the 365-Day Done Right Promise.
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 West Hills Customers Say
"Room addition off the kitchen. Framing, drywall, and paint all done well."
- Wade L."Fixed quote and clear change orders approved by text."
- Trina M."Communication was the best part. I always knew what was happening that week without having to ask."
- Dolly N.
