Shasta County, CA Accessory Structures: ADU Rules (2026)

Section 17.88.132 of the Shasta County Code (Title 17, Zoning) establishes development standards for ADUs and junior accessory dwelling units (JADUs). ADUs may be established by right in zones permitting a one-family residence, including Urban Residential (UR), Suburban Residential (SR), Rural Residential A (R-R-A) and B (R-R-B), and the Mixed Use (MU) district. The ordinance complies with California Government Code Sections 65852.2 and 65852.22 (state ADU law). ADUs cannot exceed 1,200 square feet, and on properties with a primary residence the ADU is limited to 50% of the primary residence's living space (whichever is less). Setback requirements are four feet from side and rear lot lines for ADUs. The county does not require additional off-street parking when the ADU is within one-half mile of public transit, is part of an existing structure, or is within an architecturally and historically significant historic district. Owner occupancy is not required for permits issued through 2025 under state law. The county provides seven free pre-approved ADU designs through the Department of Resource Management to streamline permitting. Connection to public water and sewer or proof of adequate well and septic capacity is required.