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Zoning Guide

ADU Rules in Riverside

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ADU Rules in Riverside

Riverside permits Accessory Dwelling Units (ADUs) and Junior ADUs (JADUs) on all residential properties under California state law (Government Code §65852.2) and the Riverside Municipal Code (Title 19). As the county seat of Riverside County and a UC campus city, Riverside has seen growing interest in ADU construction for both family housing and rental income.

What You Can Build

Single-Family Lots (RA-5, RE, R-1 zones)

  • One ADU (attached or detached) plus one JADU per lot
  • Detached ADU: up to 1,200 square feet
  • Attached ADU: up to 1,200 sq ft or 50% of primary dwelling, whichever is less (guaranteed minimum of 850 sq ft)
  • JADU: up to 500 square feet within existing single-family structure

Multifamily Lots (R-3 zones)

  • Conversion ADUs: Up to 25% of existing units (minimum 1)
  • Detached ADUs: Up to 2 new detached ADUs per property

Size Limits

ADU Type Maximum Size
Detached ADU 1,200 sq ft
Attached ADU 1,200 sq ft or 50% of primary dwelling (min 850 sq ft guaranteed)
Junior ADU (JADU) 500 sq ft
Garage Conversion Existing footprint

Setbacks

  • Front setback: Must comply with base zone (25 ft in R-1-7000/R-1-8500)
  • Side setback: 4 feet minimum for detached ADU
  • Rear setback: 4 feet minimum for detached ADU
  • Conversion exception: ADUs in existing legal structures maintain current setbacks

Height

  • Detached ADU: 16 feet maximum
  • Attached ADU: Must not exceed height of primary dwelling
  • Near transit: Up to 18 feet for detached ADUs within ½ mile of a major transit stop
  • Multifamily lots: Up to 25 feet

Parking

No additional parking is required for ADUs under state law. Garage conversions are allowed without replacement parking. Specifically, parking is exempt when:

  • The ADU is within half a mile of a public transit stop
  • Within a historic district
  • A conversion from existing space
  • On a lot where a garage is demolished or converted for the ADU

Owner Occupancy

  • ADUs: Not required (per AB 976)
  • JADUs: Owner must occupy either the JADU or primary residence

Rental Restrictions

  • Long-term rental (30+ days) is permitted
  • Short-term rentals are generally prohibited for ADUs in Riverside
  • ADUs may not be sold separately from the primary dwelling (except under specific conditions per AB 1033)

Permit Process

ADU permits are processed through ministerial review — no discretionary approval, public hearing, or CEQA review required.

  1. Verify zoning: Check your property using Map Riverside
  2. Consult Planner on Duty: Contact the Planning Division at (951) 826-5371 for preliminary guidance
  3. Plan preparation: Prepare plans meeting California Building Code requirements
  4. Submit application: File with the CEDD Planning Division
  5. Plan review: 60-day maximum for complete applications
  6. Permit issuance: Receive building permit and begin construction
  7. Inspections: Schedule required inspections during construction
  8. Final approval: Certificate of Occupancy upon passing final inspection

Contact the Planning Division at (951) 826-5371 for questions.

Fees and Costs

  • ADUs under 750 square feet are exempt from development impact fees
  • Building permit, plan check, and inspection fees apply
  • Utility connection fees may apply for detached ADUs
  • School fees may be waived or reduced for smaller ADUs

Key Considerations

  • Riverside uses lot-size-based R-1 sub-zones (R-1-7000, R-1-8500, R-1-10500, R-1-13000) — verify your exact sub-zone
  • Check for overlay zones (S — Building Stories, X — Building Setback, ID — Innovation District) that may affect development
  • The Innovation District Overlay near the UC Riverside area has different standards
  • Solar panels are required on new detached ADUs per California Energy Code
  • Fire sprinklers are required only if the primary dwelling also has sprinklers
  • Check FEMA flood maps — Riverside has flood-prone areas near the Santa Ana River

Official Resources

More about Riverside Zoning

Sources

  1. City of Riverside ADUs/JADUs Information·riversideca.gov·Accessed 2026-04-04·Direct link
  2. Riverside Municipal Code Title 19 — Zoning·library.municode.com·Accessed 2026-04-04·Direct link
  3. California Government Code §65852.2·leginfo.legislature.ca.gov·Accessed 2026-04-04·Direct link

FAQ

Can I build an ADU in Riverside?
Yes. ADUs are allowed on all residential lots in Riverside under California state law and the city's zoning code. This includes RA-5, RE, R-1, and R-3 zones. You can build one ADU plus one JADU on a single-family lot.
Can I use my ADU as a short-term rental in Riverside?
No. Short-term rentals of ADUs are generally prohibited in Riverside. ADUs must be rented for long-term occupancy (30+ days).
How do I check if my property is eligible for an ADU?
Use Map Riverside at mapriverside.riversideca.gov to verify your property's zoning, or contact the Planning Division (Planner on Duty) at (951) 826-5371.