ADUByCity
Verified March 14, 2026

ADU Regulations in Rancho Cucamonga, California

San Bernardino County · CA · Pop. 178,000

Max ADU Size

1,200

sq ft detached

Rear Setback

4 ft

Permit Timeline

60 days for ministerial review

Build Cost

$150,000 – $310,000

Zoning

Allowed ADU Types

✓Detached ADU
✓Attached ADU
✓JADU (Junior ADU)
✓Garage Conversion
Max per lot: 2 ADUs✓ No owner-occupancy required

Rancho Cucamonga uses density-based zone designations (VL=Very Low, L=Low, LM=Low-Medium, M=Medium, MH=Medium-High). ADUs are permitted by right in all residential zones per state law.

Source: City of Rancho Cucamonga — Accessory Dwelling Units · RCMC Title 17 (Zoning Ordinance), Chapter 17.38

Dimensions

Size & Setback Requirements

Detached

1,200

sq ft max

JADU

500

sq ft max

Attached

50% of primary home, max 1,200 sq ft

Setbacks

front

Same as primary dwelling

side

4 ft

rear

4 ft

Max height: 16 ft (detached); 25 ft or match primary if attached

Lot coverage: Per underlying zone; ADUs exempt from lot coverage calculation

Conversions of existing garages or structures may have reduced or zero setbacks where the existing structure already encroaches. New detached ADUs must maintain 4 ft side and rear setbacks.

Permitting

Permit Process

Department

Planning Department

Review Timeline

60 days for ministerial review

Permit Fees

$7,000 – $14,000

Impact Fees

Impact fees waived for ADUs under 750 sq ft; proportional fees apply above that threshold

Required Documents

  • ›Site plan (to scale, showing all structures and setbacks)
  • ›Architectural floor plans
  • ›Elevation drawings
  • ›Title 24 energy compliance report
  • ›Structural drawings (new construction)
  • ›Grading/drainage plan (if applicable)

Rancho Cucamonga processes ADU permits through its online permitting portal. Inland Empire construction costs are generally 20–30% below LA/OC, making the city an attractive market for ADU investment.

Visit Planning Department →

Infrastructure

Utilities & Requirements

Solar

Required

Parking

Not required

Separate Meter

Optional

Fire Sprinklers

See note

Sewer: Connect to existing sewer lateral; separate connection generally not required for conversions
Fire Sprinklers: Not required unless primary dwelling has fire sprinklers
Parking: No additional parking required

Cucamonga Valley Water District serves most of the city; verify utility provider for your parcel. Electrical panel upgrade commonly needed for new detached ADUs.

Financials

ADU Costs in Rancho Cucamonga

Typical Build Cost

$150,000 – $310,000

Cost per Sq Ft

$210 – $280

Monthly Rental

$1,500 – $2,400/mo/mo

Property Value Added

Adds $130,000 – $260,000 to property value

Available Grants & Programs

  • ★CalHFA ADU Grant Program (up to $40,000 for eligible low-income owners)
  • ★San Bernardino County HOME Program funds may be available

Rancho Cucamonga's logistics and warehousing economy draws a large workforce, sustaining strong rental demand despite Inland Empire pricing. Garage conversions typically run $60,000–$120,000, offering strong ROI.

Use the free ADU Cost Calculator →

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Disclaimer: Information is compiled from publicly available municipal codes for general informational purposes only. It does not constitute legal, zoning, or construction advice. Regulations change frequently. Always verify with your local planning department. Last verified: March 14, 2026. Verify with Planning Department

Explore More

Nearby Cities in San Bernardino County

San Bernardino

Max 1,200 sq ft · $100,000 – $220,000

Fontana

Max 1,200 sq ft · $110,000 – $230,000

Ontario

Max 1,200 sq ft · $115,000 – $240,000

Victorville

Max 1,200 sq ft · $115,000 – $240,000

Rialto

Max 1,200 sq ft · $130,000 – $265,000

Hesperia

Max 1,200 sq ft · $115,000 – $235,000

Rancho Cucamonga Quick Facts

  • Max size1,200 sq ft
  • Rear setback4 ft
  • Permit timeline60 days for ministerial review
  • Build cost$150,000 – $310,000
  • Rental income$1,500 – $2,400/mo/mo
  • Owner occupancyNot required

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Official Source

City of Rancho Cucamonga — Accessory Dwelling Units

RCMC Title 17 (Zoning Ordinance), Chapter 17.38

Last verified: March 14, 2026

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