Are you thinking of building an ADU?

You're not alone. Whether you have a relative with special needs, an aging loved one, a boomerang kid, or just want to earn some extra income, ADUs offer a small but mighty solution to the urban housing crisis.

However, building an ADU isn't as simple as picking up your materials and getting to work. You have to have the right permits in hand, which means you need to understand your local zoning laws and building codes. Here's what you need to know.

Zoning Laws and Ordinances

California zoning laws and ordinances for ADUs vary depending on the county and city. The most significant consideration is density restrictions, but there are several others to keep in mind.

Rules related to ADUs are specified in Section 20.30 of the San Jose Zoning Code. A good place to start is by checking your zoning map and use classifications, which will determine what structures you can and cannot build.

As a rule, if you have four or less pre-existing lots, you are allowed one ADU. If you have five or more pre-existing lots, there is no limit on the number of units. However, it must fit within the property envelope and comply with local planning and building codes.

Keep in mind that due to recent re-zoning, some districts do not have density controls. This means that as long as you follow regulations on building size, shape, open space requirements, and unit mix, there is no limit on the number of dwellings you can have on your property.

Planning and Building Codes

Building codes in California are governed by the California Building Code (CBC). However, several cities have adopted their own building codes to adapt and interpret state laws based on local conditions. In San Jose, you would refer to the San Jose Building Code.

One of the big features of the building code is the type of occupancy. This determines the requirements for construction materials, fire safety, exits, and other considerations.

Buildings that can have ADUs fall under the R-M Occupancy Groups. You're most likely to deal with R-2 or R-3 dwellings.

R-2 occupancies have three or more dwellings, while R-3 has one or two. If you live in a house classified as R-3 with two dwelling units, adding an ADU will change your classification to R-2, thus changing your safety requirements.

ADUs are also allowed in any Planned Development (PD) district that does not expressly prohibit them.

The type of residence you have and the area you're in may also change the rental rules attached to your ADU--check the Department of Housing for more information on that front. You have the right to rent to whomever you choose, provided that you comply with fair housing laws.

San Jose's ADU-Friendly Policies

Here's the good news: San Jose is one of the most ADU-friendly cities in the state of California.

That's not by accident. Mayor Sam Liccardo worked with the city council to push through new regulations, guidelines, and processes over the summer which would make it easier than ever to build an ADU. The idea was simple: using ADUs as a cost-effective way to combat San Jose's unaffordable housing crisis.

For example, if you use one of the city-approved Single Family Master Plans and make an appointment to meet with city staff on Tuesdays (when the city offers an express review service) you could walk out with a building permit in 90 minutes.

The city is also looking into creating a forgivable loan program, incentivizing ADU owners to keep rent rates affordable.

The Permit Process

As you can guess, San Jose is eager to make the permit approval process as straightforward as humanly possible. But there’s much more to do.

Permits are basically a stamp of approval from the city to begin a construction project. The city has agreed that the building you've proposed is safe and meets all city planning requirements.

If you are working with an ADU specialist, contractor and/or architect, have a conversation with them about who is responsible for obtaining permits. If you're responsible for obtaining them, ask your contractor or architect to help you through the process of preparing application materials and what permits you will need.

For example, you'll need to apply for a building permit, but you may also need an electrical permit. Electrical permits inevitably make things more complicated. Some cities issue their own permits and use their own inspectors. Others only issue these permits through the state Department of Labor.

Check with local building officials about who has jurisdiction to issue an electrical permit and where to call for inspections.

Either way, you will need to submit a site plan with your application. Understand that if you submit a design and the city approves it, this becomes your final design, whether the city left it alone or made changes. You have to be prepared to accept the approved design as the design you're going to build.

What Makes San Jose Unique

Because San Jose wants to incentivize homeowners to build ADUs, the city has created a process to make it easier to start building. City officials have also developed ways to make the whole building process easier to understand.

To that end, the city created a Universal Checklist, which will be your new best friend during this process. It's there to help you find out right away if your project will need any special permits and spell out what you can and cannot do based on your property.

Plus, the city allows you to meet with a City Planner (for free!) to understand what your ADU plans should include and to address any concerns you might have.

That said, getting an appointment with a planner can still take up to 8 weeks. So expect an ADU project to take some time.

Ready to Build Your ADU?

If you're ready to get your project off the ground, we're ready to make your vision a reality.

We're ADU experts with a long background in housing advocacy. Click here to check out our available services, or talk to an ADU specialist today about your options.

Either way, you will need to submit a site plan with your application. Understand that if you submit a design and the city approves it, this becomes your final design, whether the city left it alone or made changes. You have to be prepared to accept the approved design as the design you're going to build.

Ready to Build Your ADU

If you're ready to get your project off the ground, we're ready to make your vision a reality.

We're ADU experts with a long background in housing advocacy. Click here to check out our available services, or talk to an ADU specialist today about your options.