Schedule ADU Consultation
(909) 443-1324 ext: 267
Schedule ADU Consultation (909) 443-1324 ext: 267

Riverside ADUs

Everything about building Accessory Dwelling Units in Riverside, CA

Research local zoning codes for ADU design
Calculate returns and costs to get financing
Estimate your project costs and timeline

Check your property's zoning, browse designs & get contractor estimates for your ADU project:

I'm interested in

The city government of Riverside will approve ADUs under California's statewide mandated regulations.
The California Building Code (CBC) 2019 is adopted.

Last Updated 10/13/20


City Hint: The city permitted a total of 31 ADU projects in the past year of 2019, which is below the average compared to other cities in California.

Number of ADUs allowed:

According to state law, all single-family homes are allowed at least one Accessory Dwelling Unit (ADU). Additionally, single-family lots which are owner-occupied may create one Accessory Dwelling Unit (ADU) and one Junior Accessory Dwelling Unit (JADU). Also, multi-family lots may now add one ADU per every four existing residential units, so long as they were legally established.

Types of ADUs allowed:

Detached ADU, Attached ADU, Junior ADU are approved. ADUs may be new construction or converted from existing space. JADUs must be converted from existing space.

Lot size:

Residential properties will not be subject to any minimum lot size for Accessory Dwelling Unit (ADU)s by ordinance or of the underlying zoning district. ~ Updated: State Law AB-68

ADU size:

Detached ADUs may be up to 1,200 square feet of livable space. Attached ADUs may be up to either 1,200 square feet or 50% of the size of the primary dwelling, whichever is less. For example, a 2,000- square-foot house may have an attached ADU of up to 1,000 square feet, or a detached ADU of up to 1,200 square feet.

JADUs may be up to 500 square feet in size and may be configured as efficiency or studio units


ADUs are allowed in the side and rear yards but are not allowed in front yards. In the side and rear yards, ADUs must be set back at least four feet from all property lines and from other buildings


ADUs do not require any additional parking. Additionally, if a garage or carport serving the primary dwelling is converted into an ADU, no replacement covered parking spaces for the primary dwelling are required.

Like ADUs, JADUs do not require their own dedicated parking spaces. If an existing attached garage is converted to a JADU, no replacement covered parking spaces for the primary dwelling are required.

Fire Safety:

Fire sprinklers are not required for the ADU unless they are also required for the primary unit.

Shape, materials and style:

ADU Design: No exterior stairways may be located on the side of the structure facing a public right-of way, except for alleyways.


ADUs are subject to the same height and story limits set by the Zoning Code for the primary dwelling. In most areas of the City, the maximum height is 35 feet and two stories. ADUs may also be constructed above existing structures such as garages or as second-story additions to the primary dwelling.

Design review:

ADUs will be reviewed in a Ministerial process, without discretion, and will be approved or denied within 120 days of application, according to state law.

Number of Bedrooms:

Not specified by State Standards.


An ADU can be rented separately from the primary dwelling. The property owner does not have to occupy one of the homes on the property to rent either home to other occupants. An ADU cannot be sold or conveyed separately from the primary dwelling except in limited circumstances by nonprofit affordable housing organizations

Utility connections:

ADUs may have separate utilities or may be tied into the existing connections serving the primary dwelling. Separate connections allow the ADU to be billed separately but cost more to install. Contact Riverside Public Utilities at 951-826-5489 (Electric) or 951-826-5285 (Water), or the Public Works Department at 951-826-5341 (Sewer), for more information. Gas/telecommunications questions will need to be directed to the provider in your area. In some areas of the City, electric and/or water service is provided by other agencies

Allowed Zones:

*** Beginning in 2020, according to state law, all residential zoning districts, including single-family and multi-family, are allowed to build Accessory Dwelling Units. ***

Accessory dwelling units are allowed in all single family residential zones.

Lot Coverage:

Lot Coverage: Maximum lot coverage shall comply with that of the underlying zone.

Residential Building Code:

The California Building Code (CBC) 2019 is adopted.

Call/Text ADU Operator (909) 443-1324
Dial Ext: 267
Detached ADU in Hayward, CA $9,025 saved

ADU Design Library

Browse hundreds of models to find the right fit for your property.

ADU Model 975 sqft

W 39 ft L 25 ft

ADU Model 448 sqft

W 28 ft L 16 ft

ADU Model 484 sqft

W 22 ft L 22 ft

Customer Reviews

"Housable has been a great resource regarding my ADU project. I purchased both the Property and Design Reports. In both cases, they delivered as promised and on time."

Ed in Corona, CA

"My experience with Housable was exceptional. The team was extremely helpful and responsive. I am very satisfied and happy to have used these services. As a home owner I do not know the construction lingo or process but the Housable team very kind and helpful and patient with me. My expectations were exceeded. Thank you for everything."

Monica H. in Oakland, CA

"The property report was great! Made me feel like my project is feasible."

Alexandria in Santa Ana, CA

Complete 5-Step Process

Browse hundreds of permit-ready ADU designs and order one to customize to your needs.
Connect with local contractors to get site visits and cost estimates for your project.
Mark up changes to your plans and provide critical info needed to permit your project.
Finalize your project blueprints to submit for building permits.
Select your contractor and build your project.

What our customers say:

Customer Reviews

"My permits were APPROVED, thank you for all your hard work. I am in the process of meeting with contractors. "

Mary S. in San Jose, CA

"I just wanted to let you know that the permit process has been completed and we are currently in the construction phase. The work you guys did was great and I will definitely be using this service again in the future. I will keep you guys updated on anything important. Thanks!"

Patrick L. in Orange County, CA

Detached ADU in Livermore, CA

1,003 sq. ft., 3 bed, 2 bath - Built in 2020

Completed Project

Total Project Cost:
Architectural Design Fees
Market Rate
Architecture Fees:
Percentage of Project Cost:
Housable Fees
Design + Permitting
ADU Permit Set:
Percentage of Project Cost:

Net Savings With Housable:

Estimate Your ADU Potential
Costs / ROI



* upon completion of ADU


* based on local average price per sqft


* estimated by location


* 30 years / 5% interest rate / 20% down payment


Size: 500 sqft


Appreciation Estimate = (Base Value: $) / (Home's Living Space: sqft) * (ADU's Living Space: sqft)

Rental Estimate = (Rent Per Sqft: $2.42) * (ADU's Living Space: sqft)

Check your property's zoning, browse designs & get contractor estimates for your ADU project:

Everything you need to get accurate estimates from contractors for your ADU project. Get help with ADU feasibility, design, permitting and sourcing contractors for your project in one place.

I'm interested in