Awaiting expert review. This page covers rules that vary by state and local jurisdiction. It is kept out of search results until a qualified reviewer has checked it; the sources below are dated so you can verify each point.
Quick answer
An ADU parking requirement is a local zoning rule that a new accessory dwelling unit must come with a set number of off-street parking spaces, usually on the driveway or elsewhere on the lot.
California caps it at one space per unit or per bedroom, whichever is less, bans it outright in six listed situations, and bars cities from making you replace a garage you convert or demolish.
Quick facts
- California maximum
- One space per ADU or per bedroom, whichever is less 2
- Form allowed
- Tandem on a driveway; in setback areas unless specific findings are made 2
- No parking at all
- Six cases, including within ½ mile walking distance of public transit 5
- Replacement parking
- Cannot be required when a garage, carport or space is converted or demolished 2
- Local option
- A city may reduce or eliminate ADU parking 2
- Other states
- Rules vary by state and city
Key takeaways
- A parking requirement is a rule that an ADU must come with off-street parking.
- In California a city can require at most one space per ADU or per bedroom, whichever is less.
- No space at all can be required in six listed cases, such as within a half-mile walk of transit.
- If you convert or tear down a garage for an ADU, the city cannot make you replace that parking.
- A required space may be tandem on your driveway.
- Other states set their own rules. Some cities there ask for more.
What it means, in plain English
Off-street parking means a parking space on your own lot, not on the street. A parking requirement says how many of those spaces a new ADU must have.
Tandem parking means one car parked behind another, usually on a driveway. Replacement parking means new spaces to make up for a garage or carport you remove.
In California, the state sets the most a city may ask for. A city can ask for less, or none at all 2.
Why it matters to you
Parking takes space. A standard space plus room to reach it can use much of a small backyard. On a narrow lot, a required space can decide whether an ADU fits at all.
Parking also costs money. Paving, a new curb cut or a longer driveway all add work. If your lot qualifies for an exemption, you can skip that spending and use the space for the unit or a yard.
Finally, it affects a garage conversion. Turning a garage into an ADU removes covered parking. California says you do not have to replace it 2.
What a parking requirement does to an ADU project
Parking used to be the quiet project-killer for backyard units. A required space has to fit somewhere, often where the ADU would go, and if the ADU replaces a garage the city could once ask for those spaces back. On a narrow lot that can be the difference between a buildable unit and none.
California now treats parking as a ceiling, not a floor. The rules sit in two current sections of the Government Code: Section 66314(d)(10) and (11) for the cap and replacement parking, and Section 66322 for the no-parking cases 2 5. For the full data set, see the ADU parking research.
When California bars any ADU parking requirement
| # | Condition |
|---|---|
| 1 | Within one-half mile walking distance of public transit |
| 2 | Within an architecturally and historically significant historic district |
| 3 | Part of the proposed or existing primary residence or an accessory structure |
| 4 | On-street parking permits are required but not offered to the ADU occupant |
| 5 | A car share vehicle is located within one block |
| 6 | The ADU application is submitted with a permit application for a new single-family or multifamily dwelling on the same lot |
Sources: [5]
Why the transit exemption is wider than it sounds
The half-mile test turns on how "public transit" is defined. Section 66313(m) defines it as a location, including a bus stop or train station, where the public may access buses, trains, subways and other transportation that charge set fares, run on fixed routes and are available to the public 1.
A fixed-route bus stop counts. The distance is walking distance, not a straight line on a map.
That combination puts many urban and suburban lots inside the exemption. Measure the walking route to the nearest qualifying stop before you design a parking space you may not need.
Example: three lots, one rule
Hypothetical California lots, used to show how the sections combine.
| Lot | Facts | Maximum a city can require |
|---|---|---|
| A | New detached 2-bedroom ADU, nearest bus stop a 1-mile walk, no other exemption | One space: one per unit is less than one per bedroom for two bedrooms; tandem on the driveway allowed |
| B | Same ADU, bus stop a 0.3-mile walk | None (66322(a)(1)) |
| C | Garage converted to an ADU, no transit nearby | None for the ADU, which sits in an accessory structure (66322(a)(3)); the lost garage spaces need not be replaced (66314(d)(11)) |
Illustration only. The planning department confirms which conditions apply to a real lot.
How parking fits the California review process
California ADU applications get ministerial review. That means a planner checks your plans against fixed rules, with no hearing and no judgment call 4. Parking is one of those fixed rules.
So the parking test is a yes or no check. Either your lot meets one of the six cases, or the city may ask for up to one space. A planner cannot ask for extra spaces because the street feels busy. The guide below runs the whole test in order.
A city may also choose to go further than the state. It can reduce or drop ADU parking entirely in its own ordinance 2. Check the local text, because your city may be more generous than the state floor.
- If Any one of the six § 66322(a) cases applies (for example, a half-mile walk to transit)
- Then None 5
- If The ADU replaces a garage, carport or covered space
- Then No replacement parking for the lost spaces 2
- If None of the six cases applies
- Then At most one space per unit or per bedroom, whichever is less 2
- If A space is required
- Then It may be tandem on an existing driveway 2
- If Your city’s ordinance sets less or none
- Then The lower local rule applies
California only, from Gov. Code §§ 66314(d)(10)–(11) and 66322(a), as read on 7 October 2026. The planning department confirms which case applies. Source: [2] [5]
Providing a space anyway
Reasons some owners add one
- A space can matter to tenants and to resale in car-dependent areas
- A driveway tandem space often needs no new paving
What it costs the project
- Paving and curb work add cost
- A space can consume the footprint the ADU needs
- A new driveway or curb cut may need a separate approval
How to work out what your lot needs
- Count the bedrooms planned for the ADU.
- Check whether the ADU is part of the house or an existing accessory structure, such as a garage.
- Measure the walking route from your lot to the nearest fixed-route bus stop or train station.
- Check if your lot is in a historic district, or if a car share vehicle sits within one block.
- Ask whether street parking permits are required and offered to ADU tenants.
- If none of the six cases apply, the most the city can require is one space.
- Show any required space on the site plan, tandem on the driveway if that works.
Where you will see it
- The city ADU ordinance. It states the local parking rule. Check it against state law.
- The site plan. Any required space is drawn on it, with its size and access.
- Plan check comments. A planner may ask for a space or accept an exemption.
- The application form. Many cities ask you to claim an exemption and show proof, such as a transit map.
Parking terms compared
| Term | Plain meaning | California ADU rule |
|---|---|---|
| Parking requirement | Spaces a new ADU must have | At most one per unit or bedroom, whichever is less |
| Parking exemption | A case where no space can be required | Six cases in Section 66322 |
| Replacement parking | New spaces for a garage you remove | Cannot be required for an ADU |
| Tandem parking | One car behind another | Allowed on a driveway |
Common misreadings
- Myth "Every ADU needs two parking spaces."
- Reality In California a city can require at most one, and often none 2.
- Myth "Transit means a train station only."
- Reality A fixed-route bus stop counts as public transit 1.
- Myth "Half a mile means a circle on a map."
- Reality The test is walking distance, along the route you would walk.
- Myth "My city ordinance asks for more, so I must provide it."
- Reality A local rule stricter than state law is null and void, and the state rule applies 3.
What to ask the planning department
- Which exemption does my lot qualify for, and what proof do you need?
- Which stops do you count as public transit near my lot?
- Does my lot sit in a historic district?
- Can a required space be tandem on my existing driveway?
- Would a new curb cut need a separate approval?
- Will you apply the state cap if the local ordinance asks for more?
Checklist for your project
- Print a map of the walking route to the nearest transit stop.
- Note the number of ADU bedrooms on the plans.
- Decide whether you want a space even if none is required.
- Show any space on the site plan with clear access.
- Claim any exemption in writing with your application.
- Keep the planner's written answer with your permit file.
Outside California
Other states set different parking caps, and in states without an ADU statute the city ordinance controls entirely, sometimes requiring two spaces. Check the state rule before applying California's cap.
Related guides and tools
- ADU regulations hub
- Garage conversion ADUs research
- Feasibility checkerTest your lot against the state ceilings
Questions about adu parking requirement
Does an ADU need a parking space in California?
At most one, and often none. Section 66314(d)(10) caps it at one space per unit or per bedroom, whichever is less, and Section 66322 bars any requirement in six cases, including within one-half mile walking distance of public transit.
If I convert my garage to an ADU, do I have to replace the parking?
No. Under Section 66314(d)(11), a California local agency cannot require replacement of off-street spaces lost when a garage, carport or parking space is converted or demolished for an ADU.
Does a bus stop count as public transit for the ADU parking exemption?
Yes, if it serves fixed-route transit with set fares open to the public. Section 66313(m) names a bus stop as an example.
Can the ADU parking space be in the driveway?
Yes. California law allows tandem parking on a driveway, and parking in setback areas unless the agency makes specific findings that it is not feasible.
How many parking spaces does an ADU need in California?
At most one. Section 66314(d)(10) caps it at one space per unit or per bedroom, whichever is less. Many lots need none, because Section 66322 bars any parking rule in six cases.
What counts as half a mile from transit for an ADU?
Half a mile of walking distance to public transit, such as a fixed-route bus stop or train station. It is measured along the walking route, not as a straight line on a map.
Do I need parking for a junior ADU?
A unit built as part of the main home falls under one of the Section 66322 cases, so a city cannot require parking for it. Confirm with your planning department.
Can my city require a covered or garage space for an ADU?
The state rule allows tandem parking on a driveway. A covered space requirement goes past what the state allows a city to demand, so ask the planner which section supports it.
What if my city ADU ordinance asks for more parking than state law?
A local rule that does not meet state law is null and void under Section 66316, and the state standards apply. Ask the planning department in writing which rule it is using.
Does a car share spot near my house remove the ADU parking rule?
Yes, if a car share vehicle is located within one block of the ADU. That is one of the six cases in Section 66322(a).
Sources
- California Legislative Information, Gov. Code § 66313, retrieved .
- California Legislative Information, Gov. Code § 66314, retrieved .
- California Legislative Information, Gov. Code § 66316, retrieved .
- California Legislative Information, Gov. Code § 66317, retrieved .
- California Legislative Information, Gov. Code § 66322, retrieved .
Expert review
Written by the HyreADU Research team. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.
How the numbers were checked: The cap, replacement-parking bar, six exemptions and the transit definition were each read in the current section on leginfo on 7 October 2026. Examples are hypothetical. Held for licensed review (G-REV).
Suggest a correction. We fix errors and say what changed.