San Luis Obispo County, CA Accessory Structures: Garage Conversions (2026)

Per San Luis Obispo County Code Section 22.30.470(G) (Standards to Establish One (1) Accessory Dwelling or Junior Accessory Dwelling within a Proposed Single-Family Dwelling or Existing Structure), as enacted by Ordinance No. 3409, an ADU may be created completely within the existing space of an accessory structure such as a detached garage. 'The existing accessory structure to be converted to an accessory dwelling may be expanded by a maximum of 150 square feet. Such expansion shall only be permitted to accommodate ingress and egress.' The accessory dwelling must have exterior access separate from the proposed or existing single-family dwelling, and the side and rear setbacks must be sufficient to satisfy fire and safety requirements. The maximum size of the converted ADU is 1,000 sq ft. Per Subsection (F)(5), no off-street parking spaces are required for the ADU, and existing parking demolished or converted to create the ADU is not required to be replaced. Ministerial review applies under Government Code Sections 65852.2 et seq., without discretionary review or public hearing. Converting a garage to non-ADU habitable space (e.g., a bedroom or family room not meeting ADU standards) still requires a building permit and must meet California Residential Code habitability standards (ventilation, egress, fire separation, foundation) as adopted under Title 19 of the County Code.