ADU Parking Requirements
The most common worry about converting a garage is losing the parking space, and on this point state law is unusually direct: a city cannot make you replace it. That rule has one local exception in the City of San Diego worth knowing before you plan.
California ADU law was renumbered by SB 477 in March 2024. The sections cited here are the current ones, Gov. Code 66310 to 66342. Local overlays still apply to your parcel, so confirm your specifics with your city building department or San Diego County before finalising plans.
What the rules actually say
- State law: "When a garage, carport, covered parking structure, or uncovered parking space is demolished in conjunction with the construction of an accessory dwelling unit or converted to an accessory dwelling unit, the local agency shall not require that those offstreet parking spaces be replaced" (Gov. Code 66314(d)(11))
- For a JADU, an ordinance "shall not require additional parking as a condition to grant a permit", and state housing guidance confirms that holds even when the JADU is converted from an attached garage (Gov. Code 66334(a))
- City of San Diego exception: replacement parking can be required where the property is in the Coastal Overlay Zone, within the Beach Impact Area of the Parking Impact Overlay Zone, and outside a transit priority area
- In that same City bulletin, a driveway shorter than 18 feet measured from the back of the sidewalk inward can lead the City Engineer to require the driveway be closed
- Rules change and overlays are address-specific. Confirm your parcel with your building department before committing to a plan
Common questions
Will I have to add a parking space if I convert my garage?
State law bars a local agency from requiring replacement parking when a garage is converted to an ADU (Gov. Code 66314(d)(11)). The City of San Diego lists one exception, for parcels in the Coastal Overlay Zone that sit within the Beach Impact Area of the Parking Impact Overlay Zone and outside a transit priority area. If you are near the coast, confirm your specific parcel with Development Services first.
Does a junior ADU trigger a parking requirement?
No. A JADU ordinance "shall not require additional parking as a condition to grant a permit" (Gov. Code 66334(a)), and state housing guidance has confirmed that applies even where the JADU is converted from an attached garage.
What happens to my driveway?
Usually nothing. The City of San Diego bulletin does note that where the driveway is less than 18 feet long measured from the back of the sidewalk inward, and the curb no longer complies, the City Engineer can require the driveway be closed. That is a site-specific call your plan checker makes, so raise it early if your driveway is short.
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