How United Build Partners helps Corona 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 Corona'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 Corona
Like every California city, Corona's ADU rules sit on the statewide floor — ministerial review and a 60-day clock on complete applications (our California ADU laws guide covers the framework). What stands out locally is the documentation: Corona publishes its rules in homeowner-usable form rather than leaving you to read the municipal code cold.
What's specific to Corona
- Published ADU Regulations and Guide Sheet. The city's ADU Regulations (effective January 1, 2020) and an ADU Guide Sheet updated October 28, 2024 are posted on the Planning Division's Design Guidelines and Forms page — read the guide sheet before your first counter visit.
- ADU Flow Chart. The Building Division publishes a flow chart of the ADU process on its Plan Check Submittal Requirements page — useful for understanding the sequence from application through inspection.
- AB 1332 preapproval in intake. Corona directs design professionals who want plans pre-approved under AB 1332 to BuildingPlancheck@CoronaCA.gov. We haven't found a published catalog of already-approved plans yet, so treat this as an emerging program — ask the Building Division what's currently available.
- One counter for questions. Planning and Development operates from 400 S. Vicentia Ave, Suite 120 — plan check questions and ADU submittal requirements run through the Building Division there.
Property and lot considerations
Corona's housing stock leans newer than the region's older cores — large master-planned tracts, many governed by HOAs, alongside hillier terrain toward the city's southern edges. Two practical consequences: if your neighborhood has an HOA, read our guide on what HOAs can and can't do about ADUs before you design anything; and sloped lots change foundation and site-work costs enough to be worth flagging at the walkthrough stage. Newer tracts also tend to have tighter side yards — which makes the buildable envelope question worth answering before falling in love with a floor plan.
Common ADU types for Corona homeowners
On Corona's conventional suburban lots, the detached ADU and garage conversion are the paths we discuss most — conversions especially where three-car garages give room to spare. An attached ADU can fit where side-yard geometry allows, and a JADU remains the lowest-cost option for converting existing interior space.
Cost factors in Corona
Inland Empire construction pricing generally sits below coastal-county levels, but site conditions — slope, access, utility runs in larger yards — can offset that quickly. Our cost guide covers the SoCal ranges and their exclusions; pair it with the soft-costs guide and Corona's own fee schedule from the Building Division for a complete budget.
Financing your Corona 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
The program is in its intake phase: the city invites designers to submit plans for AB 1332 preapproval via BuildingPlancheck@CoronaCA.gov, but we haven't found a published catalog of approved plans yet. Ask the Building Division what's currently available — and under AB 1332, once a preapproved plan is used, the city must act on a complete application within 30 days.
The Planning Division posts the ADU Regulations and a homeowner-oriented ADU Guide Sheet (updated October 2024) on its Design Guidelines and Forms page, and the Building Division posts an ADU process flow chart. Together they're the clearest starting package — bring questions to 400 S. Vicentia Ave or call 951-736-2262.
Generally no — California law limits HOAs' ability to prohibit ADUs on single-family lots, though reasonable restrictions can apply. Corona has many HOA-governed neighborhoods, so read your CC&Rs and our HOA guide early.