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
An ADU in West Hills, CA is a practical way to add living space on a lot you already own, without leaving the neighborhood you chose for its quiet streets and canyon-adjacent setting. Most West Hills homeowners we talk with are weighing a detached ADU in the backyard against a room addition on the main house, and the right answer usually comes down to your lot’s slope, your setback lines, and how you want the new square footage to live. We’re Sutton ADU Builders, and we handle all three. Call (472) 248-8213 when you want a written price before any work starts.
Why West Hills Homes Are Different
West Hills sits at the western edge of the San Fernando Valley, where the terrain starts rolling up toward the Santa Monica Mountains. That changes ADU work in ways you don’t see in flatter parts of the Valley. Lots here often carry a grade change of several feet front to back, which means a detached ADU frequently needs a retaining wall, extra foundation work, or a stepped slab. On hillside parcels in the streets above Sherman Way and Platt Avenue, drainage becomes the first conversation, not the last. Water moving across a sloped lot will find its way toward any new structure, and a poorly planned pad can send runoff toward your house or your neighbor’s foundation.
The housing stock matters too. West Hills grew in waves, with ranch houses and split-levels from the 1960s and 70s making up a large share of the streets east of Valley Circle Boulevard. Those homes have real backyards, which is good for ADU siting, but their original utility panels are often sized for the era. A detached ADU with its own kitchen and mini-split nearly always requires a panel upgrade or a separate subpanel, and that cost belongs in your budget from day one. Some West Hills neighborhoods fall under HOA rules that add a design-review step before the city will even look at the permit, so we map that out early and don’t let it surprise you at plan check.
Our Main West Hills Services
Three kinds of work make up most of what we do in West Hills: home additions that extend the main structure, detached ADUs in the backyard, and room additions that solve a single pressing problem. Each has its own local page with full pricing and trade-specific detail.
Home Addition Contractor in West Hills
A home addition in West Hills usually means extending the main house outward: a larger kitchen, a primary suite, or a family room that opens to the backyard. On split-level lots, we often tie the new roofline into the existing ridge so the addition doesn’t look stitched on. The structural work has to account for the age of the original framing, and on sloped parcels the foundation detail drives much of the budget. That’s the project where a written price matters most, because site conditions can shift the number quickly if nobody priced them up front. See the full breakdown on our Home Addition Contractor in West Hills page.
ADU Builders in West Hills
A detached ADU in West Hills is the project we’d start with if your lot is deep enough, because it adds rentable or family space without touching your existing home’s roofline, systems, or daily routine. The site work is the variable: slope, soil, drainage, and how far the new unit sits from the main electrical panel. We walk every West Hills lot before quoting, and we put the site-prep line items in writing so you’re not waiting for a change order after excavation begins. Full pricing, timelines, and what the 365-Day Done Right Promise covers are on the ADU Builders in West Hills page.
Room Addition Contractor in West Hills
A room addition in West Hills is the tightest-scope version of a home addition: one room, one purpose, one permit. We see a lot of these on 1960s and 70s ranches where a family needs a home office, a ground-floor bedroom for an aging parent, or a laundry room that isn’t a hallway. Because the scope is smaller, the written price is easier to hold, and the work typically disturbs less of the house while it’s underway. Local conditions still apply, especially with slab foundations and older shear walls. Details are on the Room Addition Contractor in West Hills 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 West Hills
We work regularly with Dvele, Mighty Buildings, and Boxabl systems in West Hills, and we stock common replacement hardware and trim locally so schedule slips don’t stretch into weeks. Our team stays current with our brands and their install requirements.
Pricing for ADU Company in West Hills, CA
These are the ranges we quote most often for West Hills work. Sloped lots, HOA design review, and panel upgrades are the three most common reasons a final number lands at the upper end.
| Service | Typical range in West Hills |
|---|---|
| Detached ADU, standard site | $180,000 – $320,000 |
| Detached ADU, sloped or hillside lot | $220,000 – $380,000 |
| ADU foundation and site work only | $35,000 – $80,000 |
| Garage conversion to ADU | $95,000 – $170,000 |
| Home addition, 250 – 400 sq ft | $90,000 – $160,000 |
| Home addition, 400 – 800 sq ft | $150,000 – $260,000 |
| Room addition, single room | $55,000 – $110,000 |
| Electrical panel upgrade (if required) | $3,500 – $7,000 |
| Permits and plan check for ADU | $4,000 – $9,000 |
| Site prep, drainage, and grading | $10,000 – $30,000 |
West Hills pricing runs higher than flat Valley lots when a retaining wall or drainage swale enters the picture, and older panels push the electrical line up too. Whatever the number, we hand you a written price before the first tool is lifted, and that number doesn’t change unless you change the scope.
Neighborhoods We Serve in West Hills
We work across the whole West Hills area, from the streets off Victory Boulevard up into the hillside parcels near the Upper Las Virgenes Canyon Open Space Preserve. Our crews move through the area daily, so scheduling a site visit usually happens within the week.
- Valley Circle Boulevard corridor
- Platt Avenue and Sherman Way area
- Streets south of Victory Boulevard
- Hillside lots near the canyon preserve
- West Hills neighborhoods east of Valley Circle
Service Area – Cities Near West Hills
If you’re in a neighboring community, the same written-price standard applies. We serve Canoga Park, CA, Woodland Hills, CA, Calabasas, CA, and Chatsworth, CA with the same fixed-price, photo-badged-crew process we bring to West Hills.
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
Site visits in West Hills are typically scheduled within a week of your call. The visit includes a walk of the proposed ADU or addition location, a check of the existing panel, and a look at grade and drainage. After the visit, you’ll get a written price, usually within a few business days.
Some West Hills homes fall under HOAs that require design review before the city permit moves forward. We identify that early, pull the HOA’s architectural guidelines, and submit what they need. The city permit still runs its own course, but the HOA step is common and we handle it as part of the pre-construction work.
Not unless you change the scope. The written price covers the work we described, including known site conditions like slope, drainage, and panel upgrades. If an unforeseen condition appears during excavation, we stop and bring you the numbers before doing anything that costs money. Call (472) 248-8213 to schedule your free estimate and get a written price for your West Hills project.
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
"Backyard ADU for my mother. The project manager showed ID and walked me through the permit steps, the foundation plan, and the schedule. Moved her in on time."
- Margaret C."Insulated the walls and ceiling properly. It stays comfortable even in July."
- Tamika W."They handled the drawings and the permit paperwork for us. All I had to do was pick the finishes."
- Rosa M.
