| Table of Content |
| 1. What is an ADU? |
2. Benefits of Building a Permitted ADU in California |
| 3. Types of ADUs in California |
| 4. California ADU Permit Requirements |
| 5. FAQ |
What is an ADU?
An Accessory Dwelling Unit (ADU) is a secondary housing unit located on the same lot as a primary residence. Often called secondary suites, granny flats, in-law units, or backyard cottages, ADUs are self-contained units with their own kitchen, bathroom, and entrance.
ADUs have become increasingly popular across California as a solution to the housing crisis and a way for homeowners to create additional living space or rental income.
Benefits of Building a Permitted ADU in California
Building a permitted ADU in Californiacomes with several advantages:
Rental Income: Generate steady monthly income by renting it out.
Increased Property Value: A legal ADU can significantly boost your home's market value.
Flexible Living Arrangements: Great for multigenerational living, guests, or home offices.
Sustainability: Smaller homes reduce carbon footprints.
Legal Compliance: Avoid costly fines, red tags, or forced demolition by staying permitted.
Types of ADUs in California
California law allows for different types of ADUs, depending on your property's zoning and size. Here's a breakdown:
1. Detached ADU
Standalone unit separate from the main home.
Can be built in a backyard or side yard.
Ideal for long-term rentals or independent family members.
2. Attached ADU
Physically attached to the main residence.
Shares a wall but has a separate entrance and amenities.
More cost-effective than detached units.
3. Garage Conversion ADU
Converts an existing garage into a livable space.
Fast and affordable if structure is already up to code.
4. Junior ADU (JADU)
A smaller unit (max 500 sq. ft.) created within the existing home footprint.
Must include a kitchenette and may share a bathroom with the main home.
Easier to permit due to less impact on zoning and infrastructure.
5. Basement or Attic ADU
Converts existing spaces inside your home.
Great for areas with space constraints or high land value.
California ADU Permit Requirements
While local laws may vary, the State of California has standardized many ADU rules to simplify the permitting process.
✅ General ADU Permit Guidelines:
No minimum lot size restrictions
No owner-occupancy requirement (until 2025, depending on city)
No impact fees for ADUs under 750 sq. ft.
Must meet local setback and height limits
Fire safety and utility connections may be required
🏢 City-Specific Requirements:
Check with your local planning department for:
Zoning compliance
Maximum unit size (often 850-1,200 sq. ft.)
Design standards
Parking exemptions (common near transit)
Permitting can take anywhere from 4 to 6 months, depending on complexity and city workload. It's advised to work with an experienced ADU designer or permit specialist.
