Rialto, CA Accessory Structures: ADU Owner Occupancy (2026)

070 governs accessory dwelling units citywide in Rialto's single-family and multi-family residential zones. Subsection H addresses occupancy directly: the accessory dwelling unit may be occupied without limitation, and if rented, the rental term must exceed thirty days, but neither the primary dwelling nor the accessory unit has to be owner-occupied. 22 as units of five hundred square feet or less built entirely within an existing single-family home: for a JADU, owner occupancy of either the primary residence or the JADU itself is required. Because standard ADUs carry no occupancy mandate, an owner can lease out the main house, the ADU, or both simultaneously, provided each tenancy runs longer than thirty days under subsection H's rental floor.

The Community Development Department processes ADU applications ministerially within sixty days under subsection D, without a public hearing, and the property must still meet the section's other standards: a four-foot minimum side and rear setback under subsection U, a sixteen-foot or one-story height cap under subsection T, and separate utility metering under subsection V unless the unit is a conversion of existing space. The absence of an owner-occupancy rule makes Rialto's ADU program workable for landlords assembling multi-unit rental portfolios on single-family lots, since the ordinance treats the ADU as an accessory use that does not count against the lot's allowable density under subsection R.