ADU Parking Requirements: Are You Required to Add a Parking Space?

One of the most common barriers to ADU feasibility used to be the requirement to add an off-street parking space for each new unit. State ADU laws have systematically dismantled these requirements in many markets — here is where things stand.

California: no parking required in most cases

California's ADU law eliminates parking requirements for ADUs in any of these situations: within half a mile of public transit, within an architecturally or historically significant district, part of a garage conversion, within one block of a car-share vehicle, or in a city that has no minimum parking for residential uses. In practice, most urban California ADUs have no parking requirement.

Washington: no local parking requirements allowed

HB 1337 (2023) prohibits Washington cities from requiring any additional off-street parking for an ADU, full stop. This is the most complete parking exemption of any state ADU law.

Other states: parking rules vary

• Oregon: cities may not require more than one additional parking space per ADU, and none if within half a mile of transit.
• Texas, Florida and most other states: no statewide parking preemption — local rules apply, often requiring one space per ADU or per bedroom.

Why parking requirements matter for feasibility

A parking requirement on a tight lot can make an ADU impossible — there simply may not be room to add a paved space and still fit the ADU structure within setbacks and lot coverage limits. Knowing your jurisdiction's parking rule is one of the first feasibility checks to make.

Parking rules change frequently. Always confirm with your local planning department.