Tuolumne County, CA Accessory Structures: Garage Conversions (2026)

In unincorporated Tuolumne County, a garage conversion is reviewed under Title 17 (Zoning) and the County's building code. The most common pathway is converting a garage to an Accessory Dwelling Unit: under California ADU law adopted into the County's Title 17 ADU chapter, an ADU created within an existing accessory structure such as a garage is a conversion and requires no setback, and conversions are exempt from added height limits. A limited 150-square-foot expansion is permitted where needed to accommodate ingress and egress for the converted unit. Converting a garage to general habitable space that is not an ADU is also possible but is reviewed under the zoning and building codes, and the County's parking standards (Chapter 17.30 of the Ordinance Code) may require that off-street parking eliminated by the conversion be replaced, though state ADU rules waive replacement parking when the conversion creates an ADU. All conversions require building permits to ensure the new living space meets light, ventilation, egress, smoke-detection and energy requirements. Because much of unincorporated Tuolumne County is in elevated fire-hazard terrain, fire-safety and defensible-space measures in the building code may also apply, and sprinklers can be required in limited circumstances (for example where the primary home is sprinklered). Verify whether the conversion is being processed as an ADU, since that determines which standards and exemptions apply.