ADU Parking Requirements in California: What You Need to Know

ADU Parking Requirements: California's Rules Explained

Parking requirements have historically been one of the biggest barriers to building Accessory Dwelling Units in California. Before recent state legislation, many cities required one or two additional parking spaces for each ADU, which effectively prevented homeowners with small lots or no extra parking space from building an ADU.

Fortunately, California state law has dramatically simplified ADU parking requirements. In most situations, no additional parking is required when you build an ADU. However, the rules have nuances that every homeowner should understand before starting their project.

This guide explains the current state of ADU parking requirements in California, covers the extensive list of exemptions, addresses common misconceptions, and provides practical strategies for meeting any parking requirements that do apply to your project.

California State Law on ADU Parking

Under California Government Code Section 65852.2, the baseline parking requirement for a standard ADU is one parking space per unit or per bedroom, whichever is less. However, this baseline requirement is subject to a long list of exemptions that eliminate the parking requirement for the vast majority of ADU projects in California.

The Exemption List: When No Parking Is Required

California law exempts ADUs from any parking requirement when any one of the following conditions is met:

Exemption	Description
Transit proximity	Within 1/2 mile of a public transit stop
Historic district	Located within an architecturally or historically significant district
Car-share vehicle	Car-share vehicle is located within one block of the ADU
Permitted parking	On-street parking permits are required but not offered to the ADU occupant
Garage conversion	The ADU is a conversion of an existing garage, carport, or covered parking structure
Within existing space	The ADU is created within the existing space of the primary dwelling or accessory structure
JADU	The unit is a Junior ADU (JADU) of 500 sq ft or less

The transit proximity exemption alone covers a massive portion of California's urban and suburban areas. In Los Angeles, for example, the Metro bus and rail system is extensive enough that the majority of residential properties are within half a mile of a transit stop. This single exemption eliminates the parking requirement for most ADU projects in the city.

How "Public Transit" Is Defined

California defines a "public transit" stop broadly. It includes bus stops, rail stations, ferry terminals, and any other fixed-route transit service. The 1/2-mile distance is measured as walking distance, not straight-line distance. In practice, this covers most urban and many suburban properties in California's major metropolitan areas.

To determine if your property qualifies for the transit exemption, you can use Google Maps to measure the walking distance from your property to the nearest transit stop. If it is 0.5 miles or less, you are exempt from ADU parking requirements.

Parking and Garage Conversions

One of the most important parking provisions in California's ADU law relates to garage conversions. When you convert an existing garage, carport, or covered parking structure into an ADU, the local jurisdiction cannot require you to replace the eliminated parking spaces.

This applies to both attached and detached garages, regardless of the number of parking spaces being eliminated. It also applies regardless of whether any other parking exemption applies to your property.

What This Means in Practice

If you have a two-car garage and convert it into an ADU, you are losing two parking spaces. Under state law, the city cannot require you to:

• Build a new garage or carport
• Create new off-street parking spaces on your property
• Provide replacement parking in any form

This provision was specifically designed to remove one of the biggest obstacles to garage conversion ADUs. Before this law, many cities required replacement parking for converted garages, which was often impossible to provide on smaller lots, effectively blocking the projects.

When Parking IS Required

In the relatively rare situations where none of the exemptions apply, the maximum parking requirement is one space per unit or per bedroom, whichever is less. Here is what that looks like in practice:

ADU Type	Max Parking Required	Notes
Studio ADU	1 space	1 per unit
1-bedroom ADU	1 space	1 per bedroom = 1 per unit
2-bedroom ADU	1 space	1 per unit is less than 2 per bedroom
JADU	0 spaces	Always exempt

Parking Space Requirements When They Apply

If parking is required, the space must meet the following standards:

• Size: Standard parking space dimensions (typically 8.5 feet by 18 feet)
• Location: Can be provided as tandem parking (one behind the other) in the existing driveway
• Covered vs. uncovered: Covered parking is not required; an open parking space is sufficient
• Setback: The parking space can be located in any setback area, including the front yard setback

The ability to provide tandem parking in the existing driveway is key. Most single-family homes in California have driveways long enough to accommodate at least one tandem parking space, so even in the rare cases where parking is required, it can usually be accommodated without major site modifications.

Local Variations and How to Respond

While California state law sets the ceiling on what local jurisdictions can require, some cities may try to impose stricter parking requirements or create additional hurdles. Here is how to handle common situations.

When Your City Asks for More Than State Law Allows

If your local planning department tries to require parking that conflicts with state law, you have several options:

1. Cite the specific state code: Reference California Government Code Section 65852.2 and the specific exemption that applies to your project.
2. Request a supervisor review: Ask to speak with a planning supervisor or manager who may be more familiar with current state law.
3. File a complaint with HCD: The California Department of Housing and Community Development (HCD) has the authority to review and enforce state ADU law against non-compliant local jurisdictions.
4. Consult a land use attorney: If informal resolution fails, a letter from an attorney citing state law often resolves the issue quickly.

Practical Parking Strategies for ADU Properties

Even when parking is not legally required, providing convenient parking for ADU tenants can make your rental unit more attractive and command higher rents. Here are practical strategies for managing parking on ADU properties.

Driveway Optimization

Many California driveways can be widened or extended to accommodate additional vehicles. Check your local setback requirements, but widening a driveway by 2 to 4 feet can often create enough space for a parallel parking area. Cost: $2,000 to $5,000 for driveway widening.

Permeable Parking Pads

A permeable parking pad (grass pavers or permeable concrete) can provide a parking space without adding impervious surface area to your property. These are less visually intrusive than a traditional concrete parking space and may satisfy local stormwater requirements. Cost: $2,000 to $4,000 for a single parking space.

Carport Structures

A simple carport provides covered parking at a fraction of the cost of a garage. Modern carport designs can complement your ADU aesthetic while providing weather protection for vehicles. Cost: $3,000 to $8,000 for a single-car carport.

Frequently Asked Questions About ADU Parking

Do I need to provide parking for my ADU in Los Angeles?

In most cases, no. The vast majority of residential properties in Los Angeles are within 1/2 mile of a public transit stop, which exempts them from ADU parking requirements. Additionally, if you are converting a garage, no replacement parking is required regardless of transit proximity. Contact the LA Department of Building and Safety to confirm the parking requirements for your specific property.

Can my city require me to replace parking I lose when converting my garage?

No. Under California Government Code Section 65852.2(a)(6), local agencies cannot impose parking standards on an ADU that involves the conversion of an existing garage, carport, or covered parking structure. This applies statewide, regardless of any local ordinance to the contrary.

What if I am building a new detached ADU (not a garage conversion)?

For a new detached ADU, parking requirements depend on whether any of the state exemptions apply to your property. The most common exemption is transit proximity (within 1/2 mile of a transit stop). If no exemption applies, the maximum parking requirement is one space per unit. This space can be provided as tandem parking on your existing driveway.

Can I provide tandem parking to meet ADU parking requirements?

Yes. California law specifically allows tandem parking (one car behind another) to satisfy ADU parking requirements. This means you can use your existing driveway to provide the required parking space without adding new paved areas to your property.

Does my JADU need parking?

No. Junior ADUs (JADUs) are always exempt from parking requirements under California law, regardless of transit proximity or any other factor. This is one of the many advantages of building a JADU.

What if my HOA requires parking for ADUs?

California state law generally preempts HOA restrictions on ADUs. Under AB 670, HOAs cannot unreasonably restrict ADU construction, which includes parking requirements that go beyond what state law allows. However, HOA disputes can be complex, so consult with a real estate attorney if your HOA is blocking your ADU project over parking concerns.

City-by-City ADU Parking Exemption Details in California

California's statewide ADU laws significantly relaxed parking requirements, but implementation varies by city. Understanding the specific rules in your municipality helps you plan your ADU project more effectively and avoid unnecessary expenses. Here is a detailed breakdown of parking requirements in California's major cities.

Los Angeles ADU Parking Rules

The City of Los Angeles has been one of the most progressive cities in California when it comes to eliminating ADU parking barriers. Under current LA regulations:

• No additional parking is required for any ADU located within one-half mile of a public transit stop
• No parking is required for any ADU that is part of an existing structure (garage conversion, basement conversion, or addition to the main home)
• No replacement parking is required when converting a garage to an ADU
• For detached new-construction ADUs not near transit, the city may require one parking space, but this can be met with tandem parking or in driveway configurations
• Junior ADUs (JADUs) never require additional parking in Los Angeles

In practice, the vast majority of ADUs built in Los Angeles qualify for full parking exemptions due to the city's extensive public transit network. If you are building in LA, consult our guide to the Los Angeles ADU permit process for the most current information.

San Francisco ADU Parking Rules

San Francisco has eliminated all off-street parking requirements for ADUs citywide. This applies regardless of:

• The location of the ADU on the property
• Proximity to public transit
• Whether a garage is being converted
• The size or type of ADU being constructed

San Francisco's comprehensive parking exemption reflects the city's dense urban character and robust public transportation system. Homeowners who convert garages to ADUs are not required to replace the lost parking spaces. This policy has been a significant driver of ADU construction in the city, making projects more affordable by eliminating the cost of building additional parking.

San Diego ADU Parking Rules

San Diego follows California's statewide standards closely and has added its own local provisions to encourage ADU construction:

• No parking required for ADUs within one-half mile of a public transit stop (including bus routes with frequent service)
• No parking required for ADUs that are part of an existing structure or existing accessory structure
• No replacement parking required for garage conversions
• No parking required within an architecturally and historically significant district
• For ADUs that do not qualify for exemptions, one space is required but can be provided in tandem, on the driveway, or through mechanical lifts

San Diego's extensive bus network means that many residential areas qualify for the transit proximity exemption, even in suburban neighborhoods that homeowners might not initially expect to qualify.

Oakland ADU Parking Rules

Oakland has adopted some of the most ADU-friendly parking policies in the state:

• No off-street parking is required for any ADU citywide, regardless of transit proximity
• No replacement parking is required when converting a garage, carport, or covered parking structure
• JADUs are fully exempt from any parking requirements
• The city actively encourages ADU construction as part of its housing strategy

Oakland's blanket parking exemption makes it one of the easiest cities in California for ADU development from a parking perspective. This policy has contributed to Oakland becoming one of the top cities for ADU construction in the Bay Area.

Creative Parking Solutions for ADU Properties

Even when parking exemptions apply, some California homeowners prefer to maintain or add parking options on their property. Here are creative solutions that maximize your usable space while accommodating vehicles:

Tandem Parking Configurations

Tandem parking, where cars park one behind the other in a single lane, is explicitly permitted by California's statewide ADU law as an acceptable parking arrangement. A tandem space typically requires a driveway at least 18 feet long and 8.5 feet wide. This approach allows you to maintain parking capacity without consuming additional lot area for a traditional side-by-side configuration.

Permeable Paving Solutions

Permeable paving materials such as grass pavers, permeable concrete, or gravel grid systems allow you to create parking areas that double as landscaping. These solutions satisfy parking requirements while maintaining a more attractive appearance than standard concrete or asphalt. Many California cities also provide stormwater management credits for permeable surfaces, which can help with other aspects of your ADU project approval.

Mechanical Parking Lifts

For properties with limited space, mechanical parking lifts (car stackers) allow two vehicles to park in the footprint of one space. California law specifically allows mechanical lifts to satisfy ADU parking requirements. Residential lifts typically cost $3,000 to $10,000 and can be installed on existing driveways or in garages. This solution is particularly popular in dense urban neighborhoods of Los Angeles and San Francisco.

Shared Parking Agreements

In some situations, homeowners can establish shared parking agreements with neighboring properties or nearby commercial lots. While not universally accepted by all California cities, this approach can be viable in mixed-use areas. A formal written agreement recorded with the county is typically required to use shared parking to satisfy any remaining ADU parking obligations.

Converting Front Yard Space

Some California homeowners add a parking pad in the front yard area to compensate for spaces lost to ADU construction. Local regulations vary on front-yard parking, and you may need to limit the paved area to a percentage of your front yard. Drought-tolerant landscaping around the parking area can help meet local green space requirements while providing the needed vehicle accommodation.

Frequently Asked Questions About ADU Parking in California

Can my city require more parking than the state law allows for ADUs?

No. California's statewide ADU laws set maximum parking requirements that cities cannot exceed. Under current state law, cities cannot require more than one parking space per ADU, and they must grant full exemptions for ADUs near transit, within existing structures, or in other qualifying situations. If a city attempts to impose stricter parking requirements, those requirements are unenforceable under state law. This is one of the strongest protections California provides to ADU applicants.

Do I need to replace garage parking if I convert my garage to an ADU?

No. California law explicitly states that replacement parking is not required when you convert an existing garage, carport, or covered parking structure to an ADU. This provision applies statewide regardless of your city's local ordinances. The elimination of replacement parking requirements was one of the most impactful changes in California's ADU legislation, as it removed a major obstacle that previously made garage conversions financially impractical for many homeowners.

What counts as being "within one-half mile of public transit" for ADU parking exemptions?

The one-half mile distance is measured as a walking distance from the ADU site to the nearest transit stop. Qualifying transit includes bus stops, rail stations, ferry terminals, and other public transportation stops. The transit service does not need to be high-frequency; any regularly scheduled public transit stop within the required distance qualifies. In major California cities, this exemption covers the majority of residential parcels, effectively eliminating parking requirements for most ADU projects.

Can my HOA require additional parking for my ADU?

California law limits the ability of HOAs to restrict ADU construction, including imposing unreasonable parking requirements. While HOAs can establish design standards for ADUs, they cannot impose requirements that would effectively prohibit or unreasonably increase the cost of ADU construction. If your HOA is attempting to require additional parking beyond what state law allows, you may have grounds to challenge those requirements. Consult with a local attorney familiar with California ADU law for guidance specific to your situation.

How much does it cost to add a parking space for an ADU?

Adding a standard off-street parking space for an ADU in California typically costs between $5,000 and $15,000 for a basic concrete pad, including grading, drainage, and paving. More elaborate solutions like permeable pavers can range from $8,000 to $20,000. Mechanical parking lifts cost $3,000 to $10,000 for the equipment plus installation. For covered parking or a carport structure, expect to pay $10,000 to $25,000. Given these costs, homeowners who qualify for parking exemptions can save significantly on their overall ADU budget. For more on ADU costs in California, see our comprehensive guide.

Does an ADU parking space need to be a specific size in California?

Yes, when a parking space is required for an ADU, it must meet minimum dimension standards. A standard parking space in California is typically 8.5 feet wide by 18 feet long. Compact spaces, where permitted, are generally 7.5 feet wide by 15 feet long. Tandem parking spaces must provide at least 8.5 feet of width and sufficient length for two vehicles (typically 36 feet total). Accessible parking spaces for ADA compliance must be at least 9 feet wide with a 5-foot access aisle. Your local planning department can confirm the exact dimensions required in your jurisdiction.