ADU Regulations in Rancho Cucamonga, California
Everything you need to know about building an ADU in Rancho Cucamonga — size limits, setbacks, permits, and costs.
How many ADUs are allowed in Rancho Cucamonga?
- → 1 Detached ADU (up to 1,200 sq ft)
- → 1 Attached ADU
- → 1 Junior ADU / JADU (up to 500 sq ft)
- → Up to 8 detached ADUs
- → Interior conversions up to 25% of existing units
All California cities must follow state-law minimums. Rancho Cucamonga follows California AB 68 and subsequent ADU laws.
Rancho Cucamonga ADU rules & limits.
| ADUs Allowed | Up to 3 units on a single-family lot (primary home + 1 ADU + 1 JADU); up to 8 detached ADUs on multifamily lots |
|---|---|
| Max ADU Size | 1,200 sq ft |
| Setbacks | 4 ft side & rear (CA state baseline) |
| Height | 16 ft detached |
| Parking | 1 space per ADU bedroom unless within 0.5 mile of Metrolink Cucamonga Station or the ADU is a garage conversion (parking waived in those cases) |
| JADU Allowed | Yes — up to 500 sq ft; owner-occupancy required if JADU is present |
| Impact Fees | Waived under 750 sq ft (state law) |
| Permit Timeline | 60 days maximum (state-mandated review window) |
ADUs permitted in R-1, R-2, R-3, and HR zones. Maximum lot coverage is 45% including all structures (primary residence, ADU, garage, accessory buildings). Rancho Cucamonga enforces parking unless the property is within 0.5 mile of Metrolink Cucamonga Station or the ADU is a garage conversion.
Contact: Rancho Cucamonga Planning: (909) 477-2750
What could your Rancho Cucamonga ADU earn?
Rental estimates based on current Inland Empire market rates. Actual rents vary by condition, amenities, and local demand.
Four paths to an ADU in Rancho Cucamonga.
From idea to reveal.
Free Feasibility Consultation
We walk your lot, check setbacks and lot coverage, and confirm what your jurisdiction will approve.
Design & Engineering
Floor plan, elevations, structural calcs, and Title 24 energy compliance — drawn for your specific lot.
Permit Submission & Approval
We submit to your city or county, manage plan-check corrections, and pay the permit fees.
Construction
Same Construction Station crew handles foundation, framing, MEP, drywall, and finish — start to keys.
Final Inspection & Move-In Ready
Final city inspection, certificate of occupancy where applicable, and two-year workmanship warranty.
Why build an ADU in Rancho Cucamonga.
Rancho Cucamonga has the highest median home values in the western Inland Empire, which makes ADU appraisal lift among the strongest in the region. The Metrolink Cucamonga Station parking waiver is a meaningful regulatory benefit — homeowners within a half-mile of the station avoid the per-bedroom parking requirement that applies elsewhere in the city, which unlocks ADU construction on lots where a parking pad simply doesn't fit. Etiwanda's larger 8,000–10,000 sq ft lots can comfortably accommodate a full 1,200 sq ft detached ADU within the 45% lot coverage cap. Long-term rental demand is exceptionally strong from Ontario International Airport employees, Victoria Gardens retail and restaurant workers, and Chaffey College students, and tenant quality tends to be among the strongest in the Inland Empire. Construction Station has worked through Rancho Cucamonga plan check multiple times.
Ready to build an ADU in Rancho Cucamonga?
We’ll walk your lot, confirm what Rancho Cucamonga will allow, and ballpark cost before you commit to anything.
Rancho Cucamonga ADU questions, answered.
How much does an ADU cost in Rancho Cucamonga?
How long does it take to get an ADU permit in Rancho Cucamonga?
Can I rent my ADU in Rancho Cucamonga?
Do I need owner-occupancy for an ADU in Rancho Cucamonga?
Does Construction Station build ADUs in Rancho Cucamonga?
ADU regulations change frequently. Always verify current requirements with the Rancho Cucamonga Planning Department at (909) 477-2750. This page was last updated May 2026.