Rancho Cordova, CA Accessory Structures: ADU Rules (2026)

Rancho Cordova's zoning code treats accessory dwelling units as a matter of right rather than discretionary approval. 060(D). 060(E), the city cannot require a conditional use permit, design review hearing, or public notice; it can only require a building permit, and the code sets a 60-calendar-day clock for the city to issue or deny that permit once a complete application is submitted, unless the applicant requests a delay or files simultaneously with a new-home permit application. Size and dimensional standards depend on whether the unit is attached or detached.

Attached ADUs top out at 850 square feet for a one-bedroom or 1,000 square feet for two or more bedrooms, capped at 50 percent of the existing primary dwelling's floor area, with an extra 150 square feet allowed solely for an ingress/egress addition. Detached units share the same 850/1,000-square-foot caps but get a separate height table: 16 feet for new construction, or 18 feet if the lot sits within a half-mile walk of a major transit stop or high-quality transit corridor. Both types carry four-foot side and rear setbacks, with the front setback following the primary dwelling's standard, and no setback applies when an existing structure is converted.

A junior ADU, built entirely inside the existing house, is capped at 500 square feet, needs its own entrance and an efficiency kitchen. Multifamily parcels may add ADUs by converting non-livable space up to 25 percent of existing units, plus up to two detached units, and owners must record a city-form deed restriction before permit issuance.