Redding, CA Accessory Structures: ADU Rules (2026)

140 governs accessory dwelling units and junior accessory dwelling units on any lot carrying an existing or proposed single-family or multiple-family dwelling. An ADU is not counted as a dwelling unit for calculating the lot's allowable density, and any application meeting the section's requirements must be approved without a discretionary permit or public hearing, subject only to the code's other applicable provisions and the California Building Code. A detached ADU may go on RL, RE, RS, RM, GO, GC, GC-VR, DCD, or DMUD zoned lots, plus any district carrying an MU or MU-N overlay; a junior ADU is limited to districts zoned for single-family use where the property's existing or proposed use is single-family.

A detached or attached ADU must meet, at minimum, the California Building Code's efficiency-unit standard and cannot exceed one thousand square feet, while a junior ADU is capped at five hundred square feet. Height is limited to sixteen feet for a detached ADU, rising to eighteen feet within a half-mile walk of a major transit stop or high-quality transit corridor, or for a multi-story multifamily lot, with an extra two feet allowed to match the main dwelling's roof pitch; an attached ADU can reach twenty-five feet or the zoning district's height limit, whichever is less.

The city must approve or deny a complete building permit application within sixty days, and if denied, must return written comments identifying every defective or deficient item along with the applicable code sections. Where this local section conflicts with state ADU law, state law controls.