ADU builder? The featured spot in your city is open. Call or text 424-298-3600

ADU Builders in Rancho Cucamonga, CA

31 builders · ranked by Google rating and review volume · 15 CSLB license verified

★ Featured ADU builder

Featured ADU builder — this spot is open

Put your ADU company at the top of this page, in front of Rancho Cucamonga homeowners who are comparing builders right now. Includes your logo, project photos, a direct call button and a link to your website.

📞 Call 424-298-3600💬 Text 424-298-3600

With roughly 174,453 residents at the 2020 Census, Rancho Cucamonga is one of San Bernardino County's largest communities. We found 31 ADU builders and contractors that show up for Rancho Cucamonga homeowners on Google Maps, 11 of them based in the city itself. Their average Google rating is 4.8 stars. 12 market themselves specifically as ADU builders, and 1 mention garage conversions. 15 have a matched, active CSLB license shown with a verified badge. The top-rated by our review-weighted score are JNC Construction, Skilled Home Builders and Hostetler Construction Inc..

Lots across San Bernardino County are often larger and land costs lower, which makes detached and prefab ADUs attractive. Foothill and mountain areas can face wildfire-zone construction requirements.

#6

Khan Construction Co.

4.9 (37 Google reviews)
✔ CSLB License Verified #700519

5802 Aurora Ave, Jurupa Valley, CA 91752

Serves Rancho Cucamonga · based in Jurupa Valley
Home builderGeneral contractor
CallWebsiteView profile
#7

Backyard Estates

4.9 (30 Google reviews)
✔ CSLB License Verified #1076065

2335 W Foothill Blvd #18, Upland, CA 91786

Serves Rancho Cucamonga · based in Upland
Home builder
CallWebsiteView profile
#22

OSHI Construction Inc.

5.0 (2 Google reviews)
✔ CSLB License Verified #990408

10722 Arrow Route Ste 304, Rancho Cucamonga, CA 91730

Based in Rancho Cucamonga
Remodels & additionsHome builderGeneral contractor
CallWebsiteView profile
#23

R&R Improvements

4.6 (10 Google reviews)
✔ CSLB License Verified #1087664

16226 Windcrest Dr, Fontana, CA 92337

Serves Rancho Cucamonga · based in Fontana
Remodels & additionsHome builderGeneral contractor
CallWebsiteView profile
#27

Home Masters Int'l

3.9 (38 Google reviews)
✔ CSLB License Verified #1009476

9038 Hellman Ave, Rancho Cucamonga, CA 91730

Based in Rancho Cucamonga
Remodels & additionsHome builderGeneral contractor
CallWebsiteView profile
#29

Ironbridge ADU

No rating yet (0 Google reviews)

Service-area business · Upland

Serves Rancho Cucamonga · based in Upland
ADU specialistPrefab / modularHome builder
CallWebsiteView profile
#31

Premier ADU

No rating yet (0 Google reviews)

Service-area business · Upland

Serves Rancho Cucamonga · based in Upland
ADU specialistGeneral contractor
CallWebsiteView profile

Permits and pre-approved plans in Rancho Cucamonga

ADU permits in Rancho Cucamonga go through the city's building or planning department. Under AB 1332, every California city and county had to set up a pre-approved ADU plan program by January 1, 2025, so ask Rancho Cucamonga whether it has approved plans you can use. See our pre-approved plans guide and California ADU law summary.

Planning an ADU in Rancho Cucamonga? Start here

Prefab and Modular ADUs in California: Real Costs, Permits and PitfallsGarage Conversion ADU Cost in Southern California (and What Drives It)SB 9 vs ADU: Lot Splits, Duplexes and Backyard Units in CaliforniaThe ADU Permit Process in California: Step by Step (2026)

All ADU guides →

Rancho Cucamonga ADU FAQ

How many ADU builders serve Rancho Cucamonga?

Our directory lists 31 ADU builders and contractors that appear for Rancho Cucamonga on Google Maps, including companies based in nearby San Bernardino County communities.

Do I need a permit to build an ADU in Rancho Cucamonga?

Yes. ADUs need a building permit from the City of Rancho Cucamonga, which must approve or deny a complete application within 60 days under state law. Many cities also offer pre-approved plans that speed up review.

How much does an ADU cost in Rancho Cucamonga?

Most Southern California detached ADUs land around $350 to $550 per square foot all-in, garage conversions around $200 to $350, and JADUs around $50,000 to $150,000. Use our ADU cost estimator and get three itemized bids.

How are Rancho Cucamonga ADU builders ranked here?

By Google rating weighted by the number of reviews, so a 4.9 with 200 reviews ranks above a 5.0 with 3. Featured placements are clearly labeled and don't affect the organic ranking.

Nearby cities in San Bernardino County

San Bernardino 51Fontana 83Ontario 54Victorville 16Rialto 56Hesperia 18Chino 49Upland 27Chino Hills 117Apple Valley 17Redlands 20Highland 8
📞 Call 424-298-3600💬 Text us