All ADU Regulations

Oakland, California

Oakland has updated its ADU ordinance to comply with new state laws. Read all the up-to-date requirements & know watch out for when building an ADU in Oakland.

September 15, 2023
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Oakland, CA

According to the City of Oakland's Planning & Building Department, a total of 225 ADUs were permitted in Oakland in 2022. This is a significant increase from the 100 ADUs permitted in 2021. The increase is due to a number of factors, including the city's ADU incentive program, which provides financial assistance to homeowners who build ADUs. Here’s a quick look at the requirements for building an ADU in Oakland, as of 2023:

General ADU Requirements

Oakland categorizes ADUs on single family properties as either Category 1, Category 2 or a Junior ADU (JADU):

  • Junior ADU (JADU): Conversion of a space within the existing liveable envelope of a building (e.g. an existing bedroom or living room), resulting in a living unit of not more than 500 sq. ft. Owner-occupancy in the main home or ADU is required.
  • Category 1 ADU: Conversion of space within an existing single family home, conversion or rebuild of an existing accessory structure; includes no expansion of the existing building envelope other than up to 150 sq. ft. for purposes of accommodating ADU access and egress only.
  • Category 2 ADU: Construction of a new detached or attached accessory structure, including an exterior addition to a single family home. These are the most common types of ADUs in Oakland.

ADUs must be equipped for independent living and have permanent facilities for:

  • Living
  • Eating
  • Sleeping
  • Sanitation (i.e. a bathroom)
  • Cooking
  • Exterior access that is separate from the primary dwelling

ADU kitchens must also have:

  • A sink with running water
  • Countertops and cabinetry of a reasonable size
  • A refrigerator
  • A permanent range/cooktop that doesn’t need more than 120V or natural/propane gas

JADUs may share bathroom/sanitation facilities with the primary dwelling, but they must have a separate entrance. Conversion ADUs must also have their own entrance.


All properties zoned for single family, two-family or multifamily may be eligible to build ADUs.


During the course of permitting your ADU project, you can expect to pay the following fees:

  • Plan check fee: The plan check fee is charged to review the plans for the ADU and ensure that they meet all applicable building and zoning codes. The fee is $1.50 per square foot.
  • Building permit fee: The building permit fee is based on the size of the ADU and the type of construction. The fee for a detached ADU is $234.17 per square foot, and the fee for an attached ADU is $160.08 per square foot.
  • Water and sewer connection fee: If the ADU requires a new water or sewer connection, the homeowner will be charged a connection fee. The fee is based on the size of the ADU and the location of the property.
  • School impact fee: For new detached units over 750 square feet, a school impact fee of $3.48 per square foot is charged during the building permit stage for all residential property.

In our experience in Oakland, the total cost of city permit fees ranges from $5,000 to $15,000.

Similarly, the other fees are also dependent on the specific needs of your property and the scope of your project. Our experts can help you figure out all the costs involved at the start of your project.

Number of units

The number of ADUs you’re able to build depends on how your lot is zoned:

  • Lots zoned for single family use may add 1 ADU and 1 Jr. ADU (JADU).
  • Lots zoned for two-family or multi-family may add up to 2 detached ADUs per lot or up to 25% of the existing units in the building if conversions of existing non-living space.

Building size

The maximum ADU you can build depends on the ADU type:

  • The maximum size for a JADU is 500 sq. ft.
  • 850 sq. ft. for a one bedroom detached ADU
  • 1,000 sq. ft. for a 2+ bedroom detached ADU
  • Attached ADUs cannot be greater than 50% of the existing home’s floor area.

ADUs above 800 sq. ft. may be subject to the lot coverage or floor area ratio maximums of the underlying zoning district.

Building height

Detached ADUs can reach a maximum height of 16 feet, measured from the lowest point of grade to highest point of the ADU. Attached ADUs can reach the same height as the main structure, assuming they comply with the standards for that zone.


Conversion of existing unfinished basement space can be used for an attached ADU.


Minimum setbacks of 4 feet from the side and rear lot lines, as well as 6 feet from any existing structures are required for detached ADUs. In our recent experience, Oakland allows eaves to protrude 2 ft. into the setback on side setbacks.

Existing structure conversions like detached garages common across Oakland, you can keep your legacy setbacks if you stay within the existing footprint and building envelope. it’s important to note that there can be no wall openings (like windows) within 3 ft. of the property line.

In our experience mini-split compressors (for HVAC) can be placed in the rear or side setback if the sound produced is under 45dB. Water heaters cannot be in setbacks because there is no product compliant with both sound and energy requirements. The City of Oakland requires that all exhaust vents are > 3' from the property line.


No additional parking is required for ADUs in Oakland, as the city is well served by public transportation. Even when converting a garage or carport, replacement parking is not required.

Fire safety

According to state law, if fire sprinklers aren’t required for your primary residence, then they are not required for your ADU either. There has been discussion at Oakland City Council around preventing ADUs from being built in Very High Fire Hazard Zones in the Oakland Hills. If in doubt, reach out to our team or the city for an assessment of whether this applies to your property.

Utility connections

ADUs are never required by EBMUD to have a separate water meter. Instead, the homeowners decide whether they would like a separate water meter. The majority of homeowners could provide water service to their ADU based on their existing meter, but some opt to install an additional meter.

PG&E typically requires a separate gas meter when ADUs are issued a separate and unique address. However, some exceptions apply. The Fire Marshal requires detached ADUs to have a separate address, so most detached ADUs will require a separate gas meter.


Owner occupancy is not a requirement for permitting an ADU from January 1, 2020 until January 1, 2025. This is a great opportunity for rental property owners to increase their yields in a cost-effective way.


While long-term rentals are permitted for ADUs, short-term rentals (e.g. Airbnb for less than 30 days) are not permitted in Oakland.


Are you in a creek protection area? Do you have a utility easement over your property? Reach out to us and we’ll help you build a custom ADU to fit your unique property characteristics and local regulations!


How close to my house can I build an ADU in Oakland?

When building a detached ADU, it should be at least 6 ft. away from existing structures. You cannot build a detached ADU in within the front setback area of a multi-family home. It is a good idea to check such requirements with local authorities before starting your project.

Can I convert my garage into an ADU?

Yes, if you own a single-family or multifamily home in a residential-zoned area, you may convert your garage into an ADU in Berkeley. Depending on the condition that your garage is in, the project may take under 9 months to complete and cost less than building a detached ADU. Reach out to our team to get an assessment on the condition of your garage and whether it can be converted affordably.

What is the smallest ADU I can build in Oakland?

Across California, the smallest ADU you may build is 150 sq. ft., regardless of type.

Does an ADU need a kitchen in Oakland?

Yes, ADUs must accommodate permanent and independent living, and be equipped with a fully functional kitchen.

Can I build 2 ADUs on my property in Oakland?

If your property is zoned for single-family living, then you may be eligible to build one ADU and one Jr. ADU (JADU). Multi-family properties may be able to build more detached and conversion ADUs, based on the number of dwelling units already on the property. Reach out to our team for an assessment on how many.

What is the difference between an ADU and a JADU?

ADUs may either be attached to or detached from the primary dwelling, while JADUs are contained entirely within the primary dwelling. ADUs must be equipped with permanent facilities for independent living, but JADUs need only have an “efficiency” kitchen and may share some facilities with the primary dwelling. The maximum size allowed for a JADU is 500 sq. ft., while two-bedroom ADUs in Oakland may be up to 1,000 sq. ft.

How much does an ADU increase property taxes in Oakland?

Thankfully, your existing property will not be reassessed if you build an ADU in Oakland! You can expect the value of your property to increase after you build your ADU. Since property taxes are often based on property values, this can increase your property taxes. However, any increases will only be based on the value of the ADU itself. Building an ADU will not trigger a reassessment of the value of your main home.

How many bedrooms can an ADU have in Oakland?

There’s no explicit limit to the number of bedrooms for an ADU in Oakland, however at the maximum allowable size of 1,000 sq. ft., you’d generally be able to fit 2 nicely sized bedrooms or 3 smaller ones if you get creative.

How long does it take to build an ADU in Oakland?

The entire process, from start to finish, would depend on the type of ADU you’re building, the scope of your project, and the area you’re building in. In our experience in Oakland, the permitting timeline ranges from 3-6 months. Our fastest yet was 48 days!

Can I rent my ADU in Oakland?

Yes, many homeowners we’ve worked with in Oakland rent out their ADUs, given the high demand for housing and high rents. Short-term rentals of less than 30 days are not allowed in Oakland, but you can rent out your ADU on platforms like Airbnb for 30+ days.

How many square feet can an ADU be in Oakland?

Depending on the zoning of your property, setbacks and the number of bedrooms you are hoping to include, you may be allowed to build an ADU that has a maximum area of 1,000 sq. ft. in Oakland.

Can you build a 2-story ADU in Oakland?

It is possible to build a two-story ADU in Oakland. Category 1 ADUs do not have height restrictions, but Category 2 ADUs must comply with the maximum height of the underlying zoning district.

Do I need solar on my ADU in Oakland?

Solar requirements for ADUs were updated for 2023. As of 2023, ADUs below 1,000 sq. ft. (which is currently all ADUs in Oakland) are likely exempt from solar requirements. All conversion ADUs are exempt from solar requirements.

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