What Qualifies as an ADU in California?

Are you a California homeowner looking to maximize your property’s potential? You may have heard the buzz about accessory dwelling units (ADUs) and are curious how they can benefit you. 

Get ready to know the possibilities and unlock the hidden value of your home with Nestadu by your side.

What is an ADU?

ADUs, or granny flats, in-law units, or backyard cottages, are secondary housing units on a single-family residential lot.

They can be attached to the main house, located in a separate building, or converted from existing space like a garage or basement.

Qualifies as an ADU

Qualifications for ADUs in California

In California, ADUs must meet specific qualifications to be considered legal. These include:

  • ADUs must be located on a residentially zoned property.
  • ADUs must have a separate entrance from the main house.
  • ADUs must meet local building and zoning codes.

California’s ADU Requirements

Are you considering building an accessory dwelling unit (ADU) on your property in California? Before you start construction, it’s essential to understand the state’s requirements for ADUs.

1) Maximum Size Allowances for ADUs in California

When planning your ADU, size is a crucial factor to consider. California has set maximum square footage limits for both detached and attached ADUs:

  • Detached ADUs can generally have a maximum of 1,200 square feet of living space.
  • Attached ADUs are typically limited to 50% of the primary dwelling’s area.

Remember that, depending on your property type, there may be some exceptions to these size limits. For example, multifamily buildings or homes on larger lots may have different allowances.

2) Zoning and Location Restrictions for ADUs

Before building your ADU, you must ensure it’s permitted in your zone. 

In California, ADUs are typically allowed in:

  • Single-family residential zones
  • Multifamily residential zones

However, you must check with your local zoning department for specific requirements in your area.

You must also adhere to setback requirements and distance regulations from the primary dwelling to maintain proper spacing and privacy.

Qualifies as an ADU

3) Parking Requirements and Alternatives

In most cases, California requires one additional parking space for an ADU. However, there are some exceptions and alternatives available:

  • The parking requirement may be waived if your ADU is located near public transit or in an area with parking permit programs.
  • Some cities allow for tandem parking or off-site parking as an alternative to on-site parking.

4) Owner Occupancy Rules and Exceptions

California requires that the property owner occupy either the primary dwelling or the ADU.

This helps ensure that ADUs provide housing for the owner or their family rather than being used solely as rental properties.

However, this rule has some exceptions, such as when a government agency or non-profit organization owns the property.

5) Building Codes and Safety Standards

To ensure the safety and structural integrity of your ADU, it’s crucial to comply with local building codes and safety regulations. This includes:

  • Obtaining necessary permits before starting construction
  • Undergoing inspections throughout the building process

Working with a qualified contractor and your local building department can help you navigate these requirements and ensure that your ADU meets all necessary standards.

Qualifies as an ADU


How do I know if my property qualifies for an ADU in California?

Specific criteria must be met in California for a property to qualify for an ADU. These criteria include the size and zoning of the lot, as well as local regulations and restrictions. It is advisable to consult with a local ADU specialist or the city planning department to determine if your property qualifies.

Are there any size restrictions for ADUs in California?

Yes, California has specific size restrictions for ADUs. Generally, the maximum size for a detached ADU is 1,200 square feet or 50% of the size of the main house, whichever is less. For attached ADUs, the size restrictions may vary depending on local regulations.

Can I rent out my ADU in California?

Yes, ADUs in California can be rented out to tenants. This can give homeowners additional income or housing options for family members or guests.

Are there any financial incentives for building an ADU in California?

Yes, financial incentives are available for building ADUs in California. These incentives may include reduced permit fees, property tax exemptions, and low-interest loans. 

Why Choose Nestadu?

Choosing Nestadu for your ADU project means partnering with a trusted, experienced team committed to delivering high-quality results. We have a track record of completing ADU projects in California and ensuring compliance with all regulations.

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Ready to start your ADU project? Contact Nestadu today to schedule a consultation with one of our experts.

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