Carlsbad, CA Accessory Structures: Garage Conversions (2026)

Under CMC 21.10.030 and Government Code §65852.2(a)(1)(D)(xi), Carlsbad is prohibited from requiring replacement parking when an existing covered or uncovered garage is converted to an ADU. Effective January 1, 2025, SB 1211 extended this protection so that when a garage, carport, or uncovered parking space is demolished to make way for new ADU construction, no replacement parking is required either. The existing garage footprint may remain at its current setback even if that setback is less than today's 4-foot minimum, but any expansion beyond the existing walls must meet the 4-foot side and rear setback. A garage-to-ADU conversion can be permitted as either: (1) a full ADU (up to 1,200 sq ft if expansion is included), or (2) a JADU when the garage is attached to the primary dwelling — JADUs are capped at 500 sq ft, must include an efficiency kitchen, may share a bath with the primary dwelling, and require an owner-occupancy deed restriction on either the primary unit or the JADU. The conversion requires a building permit and must meet the California Residential Code: minimum 7-foot ceiling height, emergency egress (a window meeting 5.7 sq ft net clear opening with 24-inch height/20-inch width minimum), light and ventilation, smoke and CO alarms, and one-hour fire separation between the converted unit and the primary dwelling where they share a wall. Conversions in the Coastal Zone also require a Coastal Development Permit under CMC 21.201, and for Local Coastal Program properties the city has confirmed CMC 21.10.030 setbacks take precedence over state defaults. Fire sprinklers may be required only if the primary dwelling is already required to have them (Gov. Code §65852.2(g)). The ADU permit application is the same digital-portal submission used for new construction, and ministerial review must finish within 60 days of a complete application.