Can an ADU Be Used As a Tiny House?

Here’s What You Need to Know.

A recent surge in tiny house popularity and interest in small living has led many customers to ask if an ADU can also be used as a tiny house.

The short answer is yes, an ADU can meet the same requirements for living as a tiny house, but just as there are state and local laws that govern ADUs, there are also rules and regulations for tiny houses.

Before you decide to purchase an ADU for use as a tiny house/primary residence, you need to check if your city, county, or municipality permits tiny houses in your location. Tiny houses are legal in the state of California but only in certain areas, including Sacramento, San Diego, San Francisco, and Los Angeles. Local building and zoning codes have the final say on whether or not tiny houses are permitted, and these can differ from one location to another. That’s why it’s important to make sure you are referring to the correct codes and requirements for your particular area.

Local codes may also determine which ADU models, sizes, and layouts you can choose as your tiny house. If you intend to live in a tiny house community, you will also need to follow the community’s rules.

The team at Backyard Unlimited can help you navigate all of the rules and requirements that will impact your ADU or tiny house to ensure you can meet compliance before you commit to purchasing your dwelling unit.

ADU vs. Tiny House – How Are They Different?

When comparing an ADU to a tiny house, the primary difference is how the dwelling will be used. While many considerations are involved in building an ADU or a tiny house, there’s no need to feel overwhelmed. We can assist you in determining the legal requirements for your dwelling structure and identify your options before you make a decision.

Continue reading below for more details on the differences between ADUs and tiny homes.

ADU vs. Tiny House – How Are They Different?


An ADU, or accessory dwelling unit, is supplemental living space that is added to a property where a primary residence already exists. These permanent structures include water, sewer, and power, and they are constructed in the same way as a typical home. The additional living space may be used as in-law quarters, a guest house, a rental unit, or other purpose, such as a studio or workspace. Some ADUs are combination garage/storage spaces with living space incorporated into the design. ADUs can be detached from or attached to the primary home, according to the homeowner’s needs, intended use, and local allowances.

Specific laws and regulations govern ADUs, and these rules vary from one municipality to the next.

ADU vs. Tiny House – How Are They Different?

Tiny Homes

A tiny house, or tiny home, shares many of the same features as an ADU, including plumbing, electrical, and sewer, but not all ADUs can serve as a tiny house.

According to the California Department of Housing and Community Development, a tiny house must have a minimum ceiling height of 7 feet 6 inches, at least one room that has 120 feet of gross floor area, and a net floor area of 70 square feet or more for all other habitable rooms. These requirements do not factor in other city and county codes.

For instance, in some parts of California, tiny houses are only permitted as ADUs, meaning the tiny house must share a property with a primary home. In other areas, a tiny house requires a permit or must be in a tiny home community or RV park.

Also, as of September 2023, ADUs no longer have an owner-occupancy requirement in California. So you could build an ADU and rent it out, as long as you adhere to any local rental requirements.

Options to Ownership – We’re Here to Help.

From initial consultation through final inspection, your team at Backyard Unlimited will oversee all of the details. Our design/build process helps ensure that you choose the right solution for your ADU or tiny house needs and that you comply with all state and local codes for building and inhabiting your new dwelling.

About Our Design/Build Process

Have Questions About ADU vs. Tiny House?

Give us a call at 855-630-7433 or contact our team, to discuss your project and get help designing your own private backyard space.