ADU Permit Process in Rancho Cucamonga & Ontario: Step-by-Step 2026
The ADU permit process in Rancho Cucamonga and Ontario CA stops more ADU projects than any other factor. Homeowners who plan their timeline without understanding permitting routinely discover that what they thought would take “a few weeks” actually takes three to five months. The permit phase alone can run 8—12 weeks for a complex project. […]