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

Porterville applies owner-occupancy to accessory dwelling units unevenly by type, and the dividing line is a date. For detached ADUs, section 301.16(C)(7) says that if permitted after January 1, 2025, owner-occupancy shall be required in the primary dwelling or the newly created detached accessory dwelling unit; section 301.16(D)(7) applies the identical rule, word for word except swapping in 'attached' for 'detached,' to attached ADUs. Both subsections carve out the same exception: owner-occupancy is not required if the owner is another governmental agency, land trust, or housing organization.

Junior accessory dwelling units are treated differently. Section 301.16(F)(8) requires owner-occupancy in either the remaining portion of the primary dwelling or the new junior ADU with no January 1, 2025 qualifier at all, meaning that requirement has applied to every permitted junior ADU rather than only ones permitted after that date. Conversion accessory dwelling units, covered in section 301.16(E), carry no owner-occupancy clause among their five listed standards of location, unit-count cap, floor area, setbacks and parking, so an owner converting existing multifamily space such as a storage room, boiler room or garage into a conversion ADU is not bound by an occupancy condition under this section.

The whole of section 301.16, including its January 1, 2025 date, was adopted by Ordinance 1909, effective January 21, 2025, syncing the City's rule to the date used in the state ADU law changes then taking effect. The Community Development Department checks the applicable occupancy box against the permit date when it processes an ADU building permit application.