Riverside permits ADUs, JADUs, and chassis-based MADUs (Movable ADUs) with distinct siting and design rules. Detached two-story ADUs are allowed up to 30 ft in most cases — among the most generous in California.
Detached ADU up to 1,200 sq ft livable. Attached up to lesser of 1,200 sq ft or 50% of primary, with 850 sq ft (1BR) / 1,000 sq ft (2+ BR) minimums. JADU max 500 sq ft. MADU 150–430 sq ft.
State guarantee: California requires every city to allow at least an 800 sq ft ADU exempt from local lot coverage, FAR, and front-setback rules.
Height baseline: 16 ft for detached, rising to 18 ft within ½ mile of major transit. Attached ADUs follow the primary home, capped at 25 ft.
No additional parking required for ADUs. Converting a garage/carport to an ADU/JADU requires no replacement covered spaces for the primary dwelling.
Plans by a licensed design professional submitted to Building & Safety. The city also advertises Permit-Ready ADU Plans on its website.
State backstop: A complete ADU permit must receive a decision in 60 business days. If the city stalls past 30 business days, AB 253 lets you hire a certified private plan checker to force a 10-business-day decision.
Plan check/permit issuance plus some impact and utility capacity fees. City points to CalHFA ADU grants up to $25,000 (state program).
SB 543: No impact fees on ADUs ≤750 sq ft. Above 750 sq ft, fees scale to the ratio of ADU size vs the main home.
Visit the official Riverside ADU page (link in hero) for current eligibility and downloads.
Standard ADUs in Riverside: no owner-occupancy required (made permanent in 2023).
JADUs: limited to 500 sq ft of interior livable space within an existing single-family home. Owner occupancy is required only when sanitation facilities are shared with the main house. JADUs cannot be used as short-term rentals (AB 1154 / SB 543).
Sketch a floorplan, walk through it in 3D, and have our planners review it for size, height, and setback compliance before you submit to Riverside.
Heads up: Local rules change frequently. This page summarizes publicly available state law (California Government Code §§ 66310–66342) and current local guidance for general planning purposes. Always confirm specifics with the Riverside planning desk before submitting plans. ADUMetrics does not provide legal advice.