Detached ADU
A separate backyard home with its own entrance.
City guide · Riverside County
ADUs in Riverside, California
The City of Riverside states that all residential properties in the city are eligible to create at minimum one Accessory Dwelling Unit (ADU) and one Junior ADU (JADU) in addition to the existing home. Here is what Riverside homeowners should know before planning.
What is an ADU?
An Accessory Dwelling Unit is a smaller, independent home on the same lot as a primary residence. California law sets a statewide baseline for ADUs, and each city administers its own planning review, permits and inspections.
Types of ADUs to consider
Attached ADU
Built onto the existing home with independent exterior access.
Garage or space conversion
Turns existing space, such as a garage, into a living unit.
Junior ADU (JADU)
A smaller unit created within the walls of the existing home.
What the city says
- Dwell Riverside is the city's pre-approved detached ADU program, with an accelerated review for qualifying single-family properties.
- The city lists four single-story pre-approved plans: 746 sq ft (1 bed/1 bath), 800 sq ft (2/2), 1,020 sq ft (2/2) and 1,200 sq ft (3/2), in Craftsman, Ranch and Spanish styles.
- To use the pre-approved plans, the city's eligibility form asks whether the site has a single-family home, is outside a flood zone and is not a designated or eligible Cultural Resource. Planning staff decide eligibility.
- Building permit applications are submitted online through the Riverside Public Permit Portal.
Facts on this page come from the official sources listed. Requirements can change — confirm with the city before you design or build.
How the ADU process usually works
- Learn what your city allows and check your property's zoning and site conditions.
- Set a budget and choose a pre-approved plan or a custom design.
- Prepare plans and submit them to the city for planning and building review.
- Respond to plan-check comments, pay fees and receive your permit.
- Build with required city inspections, then receive final approval.
Official resources
- City of Riverside — ADUs/JADUs (Planning)
- City of Riverside — Permit-Ready ADU Plans (Dwell Riverside)
Riverside Planning Division: (951) 826-5800, 3900 Main Street, 3rd Floor.
Statewide guidance
Common questions
Can I build an ADU on my Riverside property?
The city says all residential properties are eligible for at least one ADU and one JADU. Whether a specific design fits your lot still depends on review by the Planning Division.
How big can my ADU be, and what setbacks apply?
Size limits, setbacks, height and parking rules depend on your lot, zone and ADU type. ADU California does not publish these numbers unless we can source them directly. Confirm them with the City of Riverside Planning Division before you design.
How much are permit fees and how long does approval take?
Fees and review times change and vary by project. Ask the City of Riverside Planning Division for current fees and timelines. Our cost estimator gives a planning-level range, not a quote.
How ADU California can help
Use our free tools to understand your property and plan your budget. We are an independent homeowner resource, not a government agency — always confirm requirements with the city.
Information reviewed: 2026-10-08 · Other locations