How United Build Partners helps Riverside homeowners
We're not a construction company. United Build Partners is an ADU advisory and contractor-matching service: we start with a free review of your property and goals, help you understand what's realistic for your lot under Riverside's rules, and — when it's a good fit — connect you with up to three contractors in our network suited to your project type and neighborhood. From there, you compare proposals and decide who to work with; the licensed contractor you choose handles the actual design and construction.
ADU rules and permitting in Riverside
Like every California city, Riverside's ADU rules start with the statewide baseline — ministerial approval and a 60-day review clock on complete applications (see our California ADU laws guide). The city's Community & Economic Development Department (CEDD) administers the local process, and Riverside has invested more than most Inland Empire cities in making it navigable.
What's specific to Riverside
- Dwell Riverside permit-ready plans. The city publishes permit-ready ADU standard plans (including an 800 sq ft design) for properties in single-family zones — R-1, RE, RR, RC, and RA-5 — that have or will have a single-family home. Using one can significantly shorten design and plan review.
- Historic properties are handled differently. A property designated, or even eligible for designation, as a Cultural Resource under Title 20 of the Riverside Municipal Code can't use the permit-ready program, and the city publishes separate ADU design standards for historic properties. If your home is older, check your status early — it changes your path.
- Size standards. Detached ADUs may be up to 1,200 sq ft of livable space. Attached ADUs are capped at 1,200 sq ft or 50% of the primary home's size — with the 50% cap waived where it would prevent an 800 sq ft, one-bedroom unit.
- ADUs, JADUs and MADUs. The city's published FAQ covers Junior ADUs (up to 500 sq ft within the existing home) and also addresses movable ADUs (MADUs) — worth reading if you're considering a non-traditional unit.
- Every residential property qualifies for at least one ADU + one JADU. Per the city's FAQ, all residential properties are eligible to create at minimum one ADU and one JADU alongside the existing home, subject to standards.
Property and lot considerations
Riverside is geographically large and residentially varied — from compact older neighborhoods near downtown (where Cultural Resource status is most likely to come into play) to semi-rural parcels in RR and RA-5 zones with substantial room for a detached unit. That variation is exactly why the permit-ready program's zoning list matters: a large conventional lot in an R-1 tract may have a streamlined path, while a craftsman-era property a mile away may need custom design under the historic standards. A property review sorts out which situation you're in before you spend on plans.
Common ADU types for Riverside homeowners
Homeowners on larger Riverside lots often find the detached ADU the natural fit — especially where a permit-ready plan matches the lot. A garage conversion suits tighter lots or budgets, and a Junior ADU is the lowest-cost path where converting existing interior space works. The city's MADU provisions add a further option worth discussing at review.
Cost factors in Riverside
Construction costs in Riverside generally run somewhat below coastal Los Angeles and Orange County levels, but the same drivers apply — type, size, site conditions, and finish level. See our cost guide for SoCal ranges and what they exclude, and our soft-costs guide for the budget lines beyond the construction bid. Using a Dwell Riverside plan can reduce the design line specifically.
Financing your Riverside ADU
Most homeowners fund ADU construction through a HELOC, cash-out refinance, a construction loan, or some combination — see our ADU financing overview and loan payment calculator for how each works. Financing options aren't generally city-specific, but a lender may consider your neighborhood and local rents when evaluating projected rental income as qualifying income.
How our process works
Frequently asked questions
It's the city's permit-ready ADU plan program: pre-reviewed standard plans available for properties in single-family zones (R-1, RE, RR, RC, RA-5) with a single-family home. Using one can shorten both design and plan check. Properties designated or eligible as Cultural Resources under Title 20 aren't eligible and follow separate historic design standards.
Possibly. If the property is designated, or eligible for designation, as a Cultural Resource, the permit-ready program is off the table and the city's ADU Design Standards for Historic Properties apply. Confirm your property's status with the Planning Division early — it affects design cost and timeline.
Detached ADUs: up to 1,200 sq ft of livable space. Attached: up to 1,200 sq ft or 50% of the primary home, and the 50% cap can't prevent an 800 sq ft one-bedroom unit. JADUs: up to 500 sq ft within the existing home.