National City
Detached ADUs
Independent living units up to 1,200 sq. ft.
Attached ADUs
offering up to 1,200 sq. ft. with direct connection
Conversion ADUs
Conversion ADUs: Transform Existing Spaces
JADUs
Affordable 500 sq. ft. units within existing homes.
Key Requirements of Detached ADUs
Maximum Size: Up to 1,200 sq. ft.t.
Building Separation: Minimum 5 feet between detached ADUs and other structures.
Height:
Standard height: Up to 16 feet or the height of the primary residence, whichever is greater.
Special Allowance: Up to 18 feet for ADUs within 1⁄2 mile of a major transit stop.
Setbacks:
Front Yard: Follow local zoning rules.
Side and Rear Yards: Minimum 4 feet.
Parking:
Rules: Parking may be required unless exemptions apply.
Exemptions: No parking required if the ADU:
Is within 1⁄2 mile of public transit.
Is part of a garage or existing structure conversion.
Is located in an area with nearby car-share services.
Key Requirements of Attached ADUs
Maximum Size: Up to 1,200 sq. ft.
Height: Matches the height of the primary residence or up to 16 feet.
Setbacks:
Front Yard: Must comply with zoning rules.
Side and Rear Yards: Minimum 4 feet.
Parking:
Rules: Exempt if close to public transit or part of a converted structure.
Key Requirements of Conversion ADUs
Maximum Size: Based on the size of the existing structure.
Height: Matches the original height of the converted space.
Setbacks: Existing structures being converted do not require additional setbacks.
Parking:
Rules: No replacement parking is required for garage conversions.
Exemptions: Applies to public transit proximity or existing spaces.
Key Requirements of JADUs
Maximum Size: 500 sq. ft.
Heights: Matches the height of the primary residence.
Setbacks: Not applicable for conversions within the home.
Parking:
Rules: No parking required for JADUs.
Exemptions: Applies to all garage conversions for JADUs.
National City
Additional Requirements in National City
What is the maximum size for a detached ADU?
Answer: Detached ADUs can be up to 1,200 sq. ft.
What’s the size limit for attached ADUs?
Answer: Attached ADUs can be greater than 800 sq. ft. or up to 50% of the primary home’s size.
What are the setback requirements?
Answer: Side and rear setbacks are a minimum of 4 feet.
Are two-story ADUs allowed?
Answer: Yes, two-story ADUs are permitted if they meet setback and height standards.
Do I need to provide parking for my ADU?
Answer: No, parking is waived for ADUs near public transit, converted structures, or car-share facilities.
Can I convert my garage into an ADU?
Answer: Yes, garage conversions are allowed with no requirement for replacement parking.
How tall can my ADU be?
Answer: ADUs can be up to 16 feet tall or 18 feet near transit stops.
Can I build an ADU on a multifamily property?
Answer: Yes, up to 2 detached ADUs are allowed, plus conversions of up to 25% of existing units.
Do ADUs require separate utility connections?
Answer: Not for most single-family properties, but separate connections may be required for detached ADUs on multifamily lots.
Can I rent out my ADU?
Answer: Yes, ADUs can be rented for long-term use (31+ days), but short-term rentals are prohibited.
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