A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Chino Hills, CA
Chino Hills is one of the few cities in the Inland Empire where adding an ADU usually means working with a sloped lot, an HOA design review, and a two-story stucco home built between the 1980s and early 2000s. That changes how we engineer foundations, where we place the unit, and how fast permits move. This page is a straight-forward look at what ADU and addition work costs here, which neighborhoods we serve, and what makes Chino Hills different from flatter cities nearby. If you’re pricing a detached ADU, a home addition, or a room addition, call (831) 231-0809 and we’ll give you a written number before any work starts.
Why Chino Hills Homes Are Different
Most homes here sit on generous lots inside master-planned communities, and a large share of them fall under HOA architectural guidelines. That means an ADU often has to match the main home’s stucco finish, tile roof profile, and setback lines, which is a very different conversation than you’d have in an older, unregulated neighborhood. We’ve found that Chino Hills projects routinely start with a design review submission before a single permit is pulled.
Terrain is the second factor. Many Chino Hills backyards sit below street level, especially in the rolling sections near Butterfield Ranch and Payne Ranch. A detached ADU there may need a custom stem wall or pier foundation, not a standard slab. The climate shapes material choices too: hot, dry summers and Santa Ana wind events push us toward wildfire-resistant cladding, upgraded insulation, and low-maintenance exteriors that don’t need repainting every three years. On hillside lots, a common solution is an ADU with garage space below and living area above, which uses the grade change instead of fighting it with expensive cut-and-fill grading.
Our Main Chino Hills Services
Three jobs account for nearly every call we get from Chino Hills homeowners: full ADU builds, larger home additions, and single room additions. Each has its own page with pricing detail and project timelines.
ADU Builders in Chino Hills
A detached ADU in Chino Hills usually means a 400 to 1,200 square foot unit, often with HOA design review and hillside foundation work. We build with prefab systems from manufacturers like Cover and Dvele when the lot allows, and site-build when the terrain or HOA guidelines require a custom footprint. Chino Hills is one of the few markets where a below-street backyard actually works in your favor, allowing a garage-under design that adds square footage without major regrading. See the full ADU breakdown on our ADU Builders in Chino Hills page.
Home Addition Contractor in Chino Hills
A home addition here typically means extending the first or second story of an existing 1980s-to-2000s stucco home. Matching rooflines matters, and in HOA communities the addition has to look like it was built with the original house. Chino Hills lots usually give us room to expand sideways rather than up, which keeps foundation work simpler on sloped ground. We cover permit drawings, HOA submissions, and full construction management. See the detailed scope and pricing on our Home Addition Contractor in Chino Hills page.
Room Addition Contractor in Chino Hills
A room addition is the smallest full-construction job we take on in Chino Hills: an extra bedroom, an office, a playroom, or an expanded kitchen. On a hillside lot, even one added room can trigger a soils report if the addition extends toward a descending grade, which is why our pricing always reflects the specific lot, not a generic square-foot figure. We stock James Hardie cladding options and matching stucco materials locally, so finish matching doesn’t stall the schedule. Full cost ranges are on our Room Addition Contractor in Chino 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 Chino Hills
We’re authorized to build with Cover, Dvele, and Boxabl prefab systems, and we routinely specify James Hardie cladding on Chino Hills projects where wildfire resistance and HOA design rules intersect. Panels and finish materials are ordered with local lead times, and most prefab wall systems arrive on site within four to eight weeks of permit approval. See the full list on our brands page.
Pricing for ADU Company in Chino Hills, CA
| Service | Typical range in Chino Hills |
|---|---|
| Detached ADU, finished | $180,000 – $320,000 |
| Prefab ADU (Cover or Dvele system) | $195,000 – $350,000 |
| Garage conversion ADU | $120,000 – $210,000 |
| JADU (junior ADU inside existing home) | $85,000 – $145,000 |
| Home addition, ground level, per sq ft | $135 – $225 |
| Second-story addition, per sq ft | $185 – $310 |
| Room addition, 200 – 400 sq ft | $60,000 – $115,000 |
| HOA design review package (when required) | $1,800 – $4,500 |
| Hillside foundation work, add-on | $8,000 – $30,000 |
Chino Hills pricing runs higher than flatland cities because of HOA design review fees, hillside soils reports, and the cost of matching stucco and tile roofs on newer master-planned homes. Every project we quote gets a written price before work starts, so the number you approve is the number you pay.
Neighborhoods We Serve in Chino Hills
We run crews throughout Chino Hills, including the master-planned communities where HOA design review is the biggest variable in the schedule. Typical response time for a site visit is two to four business days depending on how many estimates are already booked that week.
- Butterfield Ranch
- Payne Ranch
- Chino Hills East
- Vellano
- Los Serranos
Service Area – Cities Near Chino Hills
Our Chino Hills crews also cover nearby cities for ADU and addition work. If you’re just outside the Chino Hills boundary, we serve Bloomington, CA, Riverside, CA, Grand Terrace, CA, and San Bernardino, CA, with the same written-pricing guarantee on every job.
Serving Chino Hills, CA - Our Local Coverage Area
We’re based in the Chino 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 Chino Hills
Yes. Most Chino Hills ADU and addition projects are in HOA-governed neighborhoods, and we handle the design review package as part of the job. We prepare elevations, material boards, and site plans that match the association’s architectural guidelines, then submit on your behalf.
It varies by project and current city workload. HOA design review typically adds three to six weeks before city permits can be submitted. Hillside lots may also require a soils report, which adds another two to four weeks. We manage the sequence so you’re not waiting on paperwork that could have been filed in parallel.
Yes, and it’s one of the most common lot types we see in Chino Hills. A garage-under ADU design often works well, allowing living space above street level without extensive grading. We assess the slope during the free site visit and price the foundation work as a separate line item so you can see exactly what the terrain adds.
Call (831) 231-0809 to schedule a free site visit and get a written estimate for your Chino Hills ADU, home addition, or room addition. We answer live, every day.
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 Chino Hills Customers Say
"Fixed quote and clear change orders approved by text."
- Trina M."Room addition off the kitchen. Framing, drywall, and paint all done well."
- Wade L."Photos of each milestone, which I loved. Slab, framing, roof dry-in, each one came with a few pictures by text."
- Gwen D.
