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

Calaveras County's current ADU rules are in Section 17.25.040 of the Zoning Code adopted July 16, 2024 (effective August 15, 2024), which replaced the older Chapter 17.66 framework. ADUs are allowed on any lot zoned to permit single-unit or multi-unit dwellings that contains, or will contain, a primary dwelling. On a lot with an existing or proposed single-unit dwelling, the County permits one detached ADU or one ADU within the existing/proposed dwelling, plus one junior ADU (JADU) within the existing/proposed single-unit dwelling. Lots with multi-unit dwellings may add two detached ADUs and conversions of up to 25 percent of non-livable space. The maximum floor area for an attached or detached ADU is 1,200 square feet; a JADU is capped at 500 square feet and must include an efficiency kitchen, with owner occupancy required for the JADU. Setbacks are a minimum of four feet from interior side and rear lot lines (five feet for an ADU built above a garage), and conversions of existing legal structures require no additional setback. The code states that automobile parking is not required for an ADU. An application that complies with the chapter and Government Code 65852.2 is approved ministerially through the building permit process and must be approved or denied within 60 days. ADUs may be rented for terms of 30 consecutive days or more but may not be sold separately from the primary residence or used as a transient (under-30-day) rental. Properties on wells serving more than one unit must demonstrate adequate water source capacity.