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

Monterey County's inland ADU ordinance (section 21.64.030) expressly addresses garage conversions. Subsection E.6 states that no setback is required for an existing garage that is converted, or demolished and reconstructed, as an ADU within the existing footprint of the structure. Where an ADU is built above a garage, a minimum 4-foot setback must be maintained from the side and rear lot lines. Consistent with state ADU law (Gov. Code 65852.2 / 66310 et seq.), when a garage, carport or covered parking is demolished or converted in connection with an ADU, the county does not require those off-street parking spaces to be replaced. A converted garage must still meet building-code requirements that apply to detached dwellings - structurally sound walls and foundation, and proper utilities (electrical, water, sewer, HVAC, insulation), which may require additional permits. The conversion is processed ministerially if it meets all applicable requirements. Units on private wells or septic systems require review by the Director of Environmental Health for adequate water and sewage.