ADU Rules in San Bernardino

San Bernardino permits Accessory Dwelling Units (ADUs) and Junior ADUs (JADUs) in all residential zones under California state law (Government Code §65852.2) and the city's Development Code, updated by Ordinance MC 1645 (effective January 2025). The city also offers a pre-approved ADU plans program to simplify construction.

What You Can Build

Single-Family Lots (RE, RL, RS, RU)

• By-right ADU: Up to 800 square feet — streamlined approval
• Standard ADU: Up to 850 sq ft (studio/1-bed) or 1,000 sq ft (2+ bedrooms)
• Attached ADU: Up to 50% of primary dwelling (minimum 800 sq ft guaranteed)
• JADU: Up to 500 square feet within existing single-family structure
• One ADU plus one JADU per lot

Multifamily Lots (RM, RMH, RH)

• Conversion ADUs: Up to 25% of existing units (minimum 1)
• Detached ADUs: Up to 2 new detached ADUs per property

Size Limits

Setbacks

• Front setback: 25 feet (matching residential zone standards)
• Side setback: 4 feet minimum for detached ADU
• Rear setback: 4 feet minimum for detached ADU
• Conversion exception: Existing structures maintain current setbacks
• Lot coverage: ADU cannot cause total lot coverage to exceed 50%

Height

• Detached ADU: 16 feet maximum
• Near transit: 18 feet within ½ mile of a major transit stop
• Attached ADU: Up to 25 feet

Parking

One parking space per ADU is generally required. Parking is exempt when:

• The ADU is within half a mile of a public transit stop
• The ADU is under 750 sq ft
• The ADU is a conversion from existing space
• A garage is demolished or converted for the ADU
• Within a historic district

Tandem parking and uncovered spaces are allowed to satisfy the requirement.

Owner Occupancy

• ADUs: Not required (per AB 976)
• JADUs: Owner must occupy either the JADU or primary residence

Rental Restrictions

• Minimum 30-day rental term — no short-term vacation rentals
• ADUs cannot be sold separately from the primary dwelling (except under AB 1033 conditions)

Pre-Approved Plans

San Bernardino offers pre-selected ADU plans to reduce design costs and speed up permitting:

• 462 sq ft plan (studio/1-bedroom)
• 738 sq ft plan (1-2 bedrooms)

Using pre-approved plans can significantly reduce the review timeline since the plans have already been checked for building code compliance.

Permit Process

ADU permits are processed through ministerial review — no public hearing or discretionary approval.

1. Verify zoning: Check your property using the interactive zoning map
2. Choose plans: Select a pre-approved plan or prepare custom plans
3. Submit application: File with the Community & Economic Development Department, Planning Division
4. Plan review: 60-day maximum for complete applications
5. Permit issuance: Receive building permit and begin construction
6. Inspections: Schedule required inspections during construction
7. Final approval: Certificate of Occupancy upon passing final inspection

Contact the Planning Division at (909) 998-2300.

Fees and Costs

• ADUs under 750 square feet are exempt from development impact fees
• Building permit, plan check, and inspection fees apply
• Pre-approved plans may reduce plan check costs
• Utility connection fees may apply for detached ADUs

Key Considerations

• San Bernardino has multiple overlay districts (Airport, Freeway Corridor, Foothill Fire, Flood Plain) — check if your property is affected
• Multi-family zones have a 35 ft height restriction within 75 feet of RS zone boundaries — this may affect attached ADUs
• The city website has transitioned from sbcity.org to sanbernardino.gov — both domains work
• Solar panels are required on new detached ADUs per California Energy Code
• Fire sprinklers required only if the primary dwelling has them
• Check FEMA flood maps — San Bernardino has flood-prone areas

Official Resources

• San Bernardino ADU Program
• San Bernardino Development Code (American Legal)
• San Bernardino Interactive Zoning Map
• California Government Code §65852.2