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The State of California is pushing for the development of accessory dwelling units (ADUs). ADUs offer exceptional housing options at an affordable rate. Recent legislation has made it the perfect time to start building an ADU on your own property. Before you get started, it is crucial you know the ADU requirements in San Jose.

DreamHome Remodeling & Builders wants to help create an accessory dwelling unit for your property. We can do that by building it and giving you the essential details to make it a legal ADU. In order to certify your ADU, you must follow the guidelines set by the City of San Jose.

ADU Resources

Before we jump into the ADU requirements in San Jose, we have listed a few helpful resources for your project:

You can find all the necessary requirements for your ADU in the resources above. We have broken down the majority of the requirements into simpler terms and reading below.


Before you jump into building an ADU, you must know if your property qualifies. Zoning is important in any residential building project. The following general plan designations qualify:

  • Downtown
  • Urban village
  • Urban residential
  • Transit residential
  • Rural residential
  • Residential neighborhood
  • Mixed-use neighborhood or commercial

If you are unsure of your designation, find out on the San Jose Online Permit Service. Once you know if you qualify, you can determine what type of property you have: single-family or duplex/multifamily. You may build a single ADU for single-family properties while duplexes can build up to three, two detached and one attached.

detached adu requrements in San Jose


There are four designations your property may have: easements, historic designation, geohazard zone, and flood zone. You can find out if your property has any of the designations by using the resources below:

If your property does have any of the above designations, it does not disqualify you from building an ADU. However, there will be additional ADU requirements in San Jose for you to meet. You’ll have to speak with public works by calling (415) 650-2586.


Now that you know your qualifying ADU requirements in San Jose, we can get into the development details. The development includes location, size, room specifications, and parking. We’ll walk you through the broad requirements of each area.


Single-family ADUs have the following options for the location:

  • Attached ADU: It must share a wall with the main residence or roof structure and be separated no more than 10 feet. The ADU’s front door cannot be facing the same street as the main dwelling’s facade.
  • Detached ADU: It must be in the backyard or 45 feet from the front of the property line. It should be at least 6 feet away from the main dwelling.

Duplex ADUs require the following:

  • Attached ADU: Must be a converted existing non-livable space such as an attic, basement, garage, etc.
  • Detached ADU: It must be in the backyard or 45 feet from the front of the property line. It should be at least 6 feet away from the main dwelling. Conversion of a detached garage or accessory dwelling is also acceptable.


The maximum square footage of your single-family ADU is based on your lot’s square footage.

  • Up to 9,000 square feet
    • Detached: 1,000-square-foot maximum
    • Attached: Up to 800-square-foot or up to 50% of primary dwelling without exceeding 1,000 square feet
  • Greater than 9,000 square feet
    • Detached: 1,200-square-foot maximum
    • Attached: Up to 800-square-foot or up to 50% of primary dwelling without exceeding 1,200 square feet

Any lot size for duplexes is limited to an 800-square-foot maximum ADU for duplexes, no matter if it’s attached or detached.

Room Specifications

Each type of room in your ADU has specific requirements it must meet in order to be approved. The details of each room are outlined below:

Sleeping Area: Your ADU may have up to two bedrooms, with each being a maximum of 400 square feet.

Kitchen: The kitchen must have a sink, food preparation counter, storage, cabinets, and a permanent cooking facility such as an oven.

Bathroom: You may have up to two bathrooms in your ADU. They require a sink, toilet, and a shower/bath facility.

Storage: Storage such as a closet may not exceed 60 square feet.

above garage adu requirements in San Jose


Finally, one of the last development ADU requirements in San Jose is parking. Not all ADUs require parking since some may be exempted from this. To determine if you do require a parking space for your ADU, visit the San Jose ADU webpage. If you do require parking for your ADU, it must be located on a solid surface without mud or dust. The minimum length of the driveway is 18 feet.

Comprehensive ADU Requirements in San Jose

The ADU requirements in San Jose we listed above are broad looks at the handbook and checklist. We encourage you to look at the resources we linked above to better understand what the City of San Jose requires. You should also check out our Complete Guide to ADUs in California. It features nearly everything regarding these beneficial structures.

You should also know that many of these ADU requirements are handled by your general contractor, like the team at DreamHome Remodeling & Builders. We can assist you in meeting each of the requirements set by the city and state. You can learn more about our ADU services by visiting its respective page on our site. You can reach us for a free estimate by calling (415) 650-2586 or filling out the free estimate form. Our team would love to help you create essential housing in the Greater San Jose area.

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