ADU Company in Los Serranos — Plans, Permits & Build, One Fixed Price

We handle the design, the engineering, and the city permit, then build it. One contract, one crew, one accountable point of contact. Free feasibility check on your lot before you commit.

✓ Licensed & Insured ✓ Written quotes ✓ Permits handled
Schedule Free Estimate

Call to schedule your free estimate

🛡 Licensed & Insured 📝 Written Fixed-Price Quotes 💲 No Change Orders · Free Estimates

ADU Company in Los Serranos, CA

Kitchen remodeling in Los Serranos means working with ranch-style and mid-century homes on larger, often sloped lots where San Bernardino County rules apply, not Chino Hills city codes. Westminster ADU Builders has served Los Serranos since 2016, and we’ve learned which older homes hide outdated wiring behind seventies cabinets and which newer tract kitchens just need better layout, not a gut job. We build both prefab and site-built ADUs, and we finish the kitchens inside them with the same crew. Call (833) 620-3521 to talk through what your Los Serranos kitchen could look like.

Call (833) 620-3521

Why Los Serranos Homes Are Different

Los Serranos sits in unincorporated San Bernardino County territory, tucked against the rolling hills that border Chino Hills State Park. That one fact changes more than people expect. Permits come from the county, not the city of Chino Hills, and hillside grading reviews slow things down on sloped parcels. We routinely see homeowners who assumed Chino Hills rules applied, then discovered county setback and defensible-space requirements they hadn’t planned for.

The housing stock runs from 1960s ranch homes on half-acre lots to newer tract builds, with horse properties mixed in along the northern edge. Older kitchens here often have load-bearing walls that were never meant to come out, original galvanized plumbing, and electrical panels sized for a 100-amp world. Summers are hot and dry, and Santa Ana winds push fire-safety requirements on exterior finishes. When we plan a kitchen or an ADU in Los Serranos, we’re thinking about grading, fire-resistant siding, and cooling loads, not just cabinet layouts.

Our Main Los Serranos Services

Most Los Serranos homeowners call us about two things: adding an ADU to a large rear yard, and remodeling a bathroom or kitchen in a home that’s ready for an update.

ADU Builders in Los Serranos

Los Serranos lots are bigger than what you’ll find down in Chino or Pomona, which means detached ADUs usually fit, even with county setback rules. The catch is slope. Homes along the hillside edges often need grading plans and retaining walls before a foundation goes in, and that’s a different process from what flat-lot Chino Hills homeowners deal with. We walk every Los Serranos client through the county checklist first, then match the build method to the lot. See ADU Builders in Los Serranos for the full breakdown.

ADU Builders in Los Serranos

Bathroom Remodeling in Los Serranos

Older ranch homes in Los Serranos often have one bathroom with original cast-iron plumbing and a layout that worked in 1965. When we remodel, we address the water lines, venting, and subfloor before we pick tile. And because we also build ADUs, the same team can handle a bathroom in the new unit and a refresh in the main house without two contractors stepping on each other. Read more at Bathroom Remodeling in Los Serranos.

Bathroom Remodeling in Los Serranos
Need help today?Fast, friendly service and a no-obligation free estimate.

Call (833) 620-3521

What happens when you call

  1. 1
    A real person answersNo phone trees — you reach a local pro.
  2. 2
    You get an upfront price rangeHonest numbers before anyone is dispatched.
  3. 3
    A background-checked tech heads outLicensed & insured, dispatched right away.
  4. 4
    You approve before work beginsNothing starts until you say go.

Kitchen Remodeling in Los Serranos

Kitchen remodeling in Los Serranos often comes down to two problems. Older ranch homes have kitchens that weren’t designed for how families cook now, with cramped layouts, too little counter space, and plumbing and electrical that predate modern appliances. Newer tract homes may have decent bones but cheap cabinets and awkward islands. Either way, the job has to account for county inspection requirements and hot summers that punish a poorly ventilated cook space.

We handle the full scope from design through finished tile and cabinet hardware. If you’re also adding an ADU, we can sequence both projects so the same crew builds the ADU and finishes its kitchen, then turns to the main house. That’s the kind of single-contractor coordination that keeps a Los Serranos project moving. For a fuller look at our process, see Kitchen Remodeling.

Full Kitchen Renovation

Signs you need it

Your Los Serranos kitchen has a layout that forces traffic through the cooking zone, cabinet boxes are delaminating from decades of heat and dry air, or the electrical panel can’t support a modern range and hood.

What it costs in Los Serranos

A full kitchen renovation in Los Serranos typically falls between $85,000 and $100,000, depending on whether walls move and how much plumbing and electrical gets replaced.

How we do it

We start with a site assessment and field measurements, then produce drawings, get county permits, demo to the studs, update plumbing and electrical, install drywall and flooring, and finish with cabinets, counters, appliances, and trim.

Cabinet Replacement and Countertop Upgrade

Signs you need it

Your cabinet boxes are sound but the doors are tired, or the counters are worn laminate or cracked tile that fights you every time you wipe them down.

What it costs in Los Serranos

Cabinet replacement and countertop work around Los Serranos generally runs $35,000 to $75,000, with the spread driven by cabinet construction, countertop material, and whether you’re changing the layout at all.

How we do it

We remove the old cabinet faces or boxes, adjust for new counter depths, install the new cabinets and counters, and reconnect the sink, faucet, and appliances with new shutoffs and supply lines.

What Kitchen Remodeling Costs in Los Serranos

Item Typical range in Los Serranos
Full kitchen renovation $85,000 – $100,000
Cabinet replacement and countertop upgrade $35,000 – $75,000
Kitchen work inside a new ADU $30,000 – $45,000

Hillside homes in Los Serranos can push costs higher when kitchens sit on slab foundations that need trenching for new drain lines, or when county inspectors require panel upgrades with the remodel. Every quote we give is a written line-item number, and we don’t pad it with change orders later.

How long does a kitchen remodel take in Los Serranos?

Expect six to ten weeks for a full Los Serranos kitchen remodel once permits are issued. County permit review adds time, especially on hillside parcels with grading notes, so we file early.

Will the price change once work starts?

No, not unless you change the scope. We write fixed-price quotes after we’ve opened walls and confirmed what’s behind them. The number we agree on is the number you pay.

Brands We Service in Los Serranos

We work with a curated set of prefab brands including Cover, Dvele, and Boxabl, keeping familiar panels and hardware accessible for Los Serranos clients rather than pushing a single vendor. See our brands for the full lineup and what each one fits best.

Pricing for ADU Company in Los Serranos, CA

Service Typical range in Los Serranos
Full kitchen renovation $85,000 – $100,000
Cabinet replacement and countertop upgrade $35,000 – $75,000
Kitchen work inside a new ADU $30,000 – $45,000
Detached ADU (prefab) $140,000 – $280,000
Detached ADU (site-built) $200,000 – $400,000
Garage conversion ADU $80,000 – $150,000
Attached ADU addition $120,000 – $250,000
Foundation and grading (hillside lots) $15,000 – $45,000
Bathroom remodel (small to medium) $18,000 – $35,000
Bathroom remodel (full, larger) $35,000 – $60,000

Sloped lots, county grading review, and fire-resistant siding requirements are the three biggest cost drivers we see in Los Serranos. You’ll get a fixed written quote before we start, and we don’t hit you with surprise change orders.

Neighborhoods We Serve in Los Serranos

We work throughout the Los Serranos side of the 91709 ZIP, from the horse-property streets along Pipeline Avenue up to the hillside parcels near the state park edge. Most of our crews reach any Los Serranos address within about thirty minutes from our Westminster base.

  • Los Serranos ranch-home streets east of Pipeline
  • Hillside parcels backing up to Chino Hills State Park
  • Tract-home sections near the Chino Hills border
  • Horse-property lots along the northern edge of 91709
  • Sloped rear-yard lots throughout unincorporated Los Serranos

Service Area – Cities Near Los Serranos

We also serve homeowners in nearby Chino, CA, where flat-lot city permitting is a different animal from Los Serranos county review. We cover Yorba Linda, CA and Montclair, CA for clients on the county edges, and we’re in Pomona, CA regularly for older housing stock that needs the same careful planning. Call and we’ll confirm we cover your street before we schedule anything.

Serving Los Serranos, CA — Our Local Coverage Area

We’re based in the Los Serranos 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 Los Serranos

Ready to get started? Free estimates · Free on-site estimates response in Los Serranos
Call (833) 620-3521

What happens when you call

  1. 1
    A real person answersNo phone trees — talk to a local adu pro.
  2. 2
    You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
  3. 3
    We come out and measureLicensed & insured, at a time that suits you — the visit and the quote are both free.
  4. 4
    You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.

What Los Serranos Customers Say

★★★★★ 5.0 from 4+ reviews

"The kitchenette layout he suggested made better use of the space than the one on our original sketch."

— Lisa Hayes

"Knew the local setback and parking rules cold, which saved us from designing something that would never have been approved."

— Daniel Norris

"Sound insulation between the unit and the main house is better than I expected. You genuinely cannot hear the tenant."

— Farah Hassan

How It Works in Los Serranos

Getting your adu handled is simple and fast.

1

Call or Request a Free Estimate

Tell us about your adu needs and we provide an upfront, transparent quote — no obligation, no hidden fees.

2

Licensed Technician Dispatched

A background-checked, certified technician arrives in Los Serranos — typically within 30–60 minutes, with parts stocked on the truck.

3

Problem Solved, Guaranteed

We complete the job to your full satisfaction, backed by our warranty and 100% satisfaction guarantee.

Request a Free Estimate

Tell us what's going on in Los Serranos — we'll get back to you fast. No obligation.

When you submit this form, you agree to our Privacy Policy and consent to receive communications via phone, email, or SMS about your request, including by the independent contractors we may refer it to.

Prefer to text? Text Now
Call Now - 24/7 Dispatch
Areas We Serve
Call Now - 24/7 Dispatch