California Accessory Dwelling Unit (ADU) Guide

What Is an Accessory Dwelling Unit?

An accessory dwelling unit (ADU) adds living space to a property that:

• Can be detached or attached to the property
• Is located on the same lot as a property
• Contains facilities that allow for adequate living independent of the main property (kitchen, bathroom, bed, etc.)

You can build these units from scratch, but people more commonly convert them from something else, such as a detached garage or a large shed.

Junior ADUs are classified separately from ADUs, as they are not required to have their own bathroom/sanitation facilities, and they also must be less than 500 square feet.

Can I Build an Accessory Dwelling Unit on My Property?

If you own a house, then you can build an ADU on your property if you so choose. Recent legislation prevents your HOA or municipal government from blocking you from building an ADU to increase housing availability. Keep in mind that this only applies to owners of houses, and HOAs can still regulate the construction of ADUs in condominium complexes.

While California homeowners can freely build ADUs, most municipalities subject these dwellings to regulation and have a rigid permit process in order to construct one. To get a permit, submit an application to your local government. It typically requires a site plan and safety precautions.

Once I Build an ADU, What Regulations Is it Subject to?

Renting out your ADU is legal in California for long-term rentals, but for short-term rentals of less than 30 days (Airbnb), many HOAs will strictly prohibit them. All rental restrictions that would apply to the main property will also apply to an ADU.

A local government or HOA may limit the maximum size of an ADU. But may not make this maximum less than 850 square feet, or less than 1,000 square feet for those with more than 1 bedroom. They must also allow the maximum height to be up to 16 feet at least. KAASS LAW helps navigate local regulations, obtain ADU permits, and resolve legal issues with HOAs or municipalities to ensure compliance.

Aspects of Building and Using ADU in California

In recent years, accessory dwelling units (ADU) have become a popular solution in California for:

• expand living space
• create rentable space
• provide independent living for family members

However, it is important to consider a number of legal and practical nuances when constructing and operating an ADU.

Zoning and Permits

California law gives homeowners the right to build ADU. However, local governments retain the authority to regulate the process. For example, you must comply with:

• building codes
• fire safety requirements
• plumbing standards

Obtaining a permit requires the submission of a detailed site plan. This includes:

• the location of the building
• utility connections
• compliance with access standards

Some counties require notification of neighbors or an environmental impact statement. In addition, ADU may not be allowed in certain seismically active areas. Or in protected historic districts. Therefore, it is important to consult with a real estate attorney before beginning construction.

Restrictions on the Use of ADU

Although ADU can be rented, there are strict rules. Rentals of less than 30 days are often prohibited. This is especially true in neighborhoods regulated by HOA, which may prohibit short-term rentals altogether. In addition, owners are required to register ADU with local authorities and comply with regulations.

Sometimes it is required that the owner live on the property where the ADU is located. Especially in the case of a rental. This requirement helps maintain order and reduces complaints from neighbors. For more information on rental regulations, visit the California Department of Housing and Community Development (HCD) website.

Other Legal Issues

It is also worth considering that ADU construction must comply with:

• insurance regulations
• utility connection requirements
• energy efficiency standards

For example, some municipalities require the installation of solar panels or energy-efficient windows.

Consider Tax and Financial Implications

Adding an ADU increases the overall value of a property. This may result in higher property taxes after reassessment. In addition, rental income from the ADU is taxable. It must be reported on your tax return. Failure to comply may result in fines. However, many see ADU as a way to increase a home’s market value and create a source of ongoing income.

Therefore, it is important to evaluate the potential costs and benefits in advance. At KAASS LAW we assist clients in drafting lease agreements. We assist in obtaining permits and resolving disputes with local governments or HOA.