California ADU Rules & Regulations

In January 2020, a whole new world opened up for ADUs in California. Here’s what you need to know about California’s ADU rules and laws.

More ADU building opportunities for California

To address the housing crisis, California passed a series of bills aimed at creating more opportunities for residents to build ADUs. Restrictions that cities, counties, and homeowners associations placed on ADU construction were lifted in 2020, creating an opportunity in every backyard across the state. As you embark on building a home addition, or an additional home, there are a few important terms you’ll want to know.

California ADU Parking Requirements

You do NOT need to build an additional parking space for an ADU if one of the following apply:

• The ADU is located within 0.5 miles from a public bus stop or rail station.
• The ADU is part of or within the primary residence or existing accessory building.
• The ADU is on a street that requires on-street parking permits but the permit has not been offered to the occupant of the ADU.
• The ADU is located within one block of where a motor vehicle provides hourly and daily service as part of a regional fleet operated by a public agency or publicly-leased motor-vehicle-sharing organization.
• The ADU is located within a historic district listed in the City’s Historic Resources Inventory.

California ADU Setbacks

The setbacks (minimum distance requirements) between structures or property lines are:

• Primary residence: 10 feet
• Side and rear property lines: 4 feet
• Front setbacks: Varies by city, per zone

California ADU Size Limits & Restrictions

The size of your units will ultimately be determined by a few factors in addition to lot size:

• 426 sq ft – The smallest unit allowed, per HUD requirements
• 850 sq ft – Max size for 1 bedroom unit (if within setbacks)
• 1000 sq ft – Max size for a 2 bedroom unit
• 1200 sq ft – Certain cities allow for larger units

We build in all of California

See ADU rules for your city

Your property is unique

Every property is subject to a variety of restrictions, be it lot size, easements, or installation logistics. Our team of experts is here to do research on your property so you don’t have to. If you’d like a free property assessment, provide your address below.

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