City ADU planning guide

Concord ADU regulations and next steps

Start with the most important planning decisions, then review the detailed city rules below before choosing a detached ADU plan or requesting a property-specific feasibility review.

Concord ADU rules overview

Detailed local requirements vary by property. Use this section as a starting point for setbacks, parking, height, utilities, and approval considerations.

Lot fit

Setbacks and buildable area

Start with rear and side setbacks, lot coverage, access, and where a detached ADU can realistically sit on the property.

Design limits

Size, height, and unit type

Check whether the property is better suited for a detached ADU, attached ADU, garage conversion, or junior ADU.

Approvals

Parking, utilities, and permits

Confirm parking exemptions, utility connection requirements, impact fees, and city review steps before finalizing plans.

Concord, CA, has detailed ADU regulations that follow state laws with some local adaptations. Below is a comprehensive overview:

Types of ADUs Permitted:

  • Detached ADUs Separate structures from the primary residence.
  • Attached ADUs Units sharing at least one wall with the main residence.
  • Conversion ADUs Converting existing structures such as garages, basements, or accessory buildings.
  • Junior ADUs (JADUs) A maximum of 500 sq. ft., created within the existing home, requiring a separate entrance and an efficiency kitchen.

Zoning and Lot Requirements:

  • ADUs are allowed in all residential zones (e.g., R-6, R-7).
  • No minimum lot size requirement applies for ADUs, consistent with California state law.

Size Limits:

  • Detached ADUs Up to 1,200 sq. ft.
  • Attached ADUs Limited to 50% of the floor area of the primary dwelling, up to 1,200 sq. ft.
  • JADUs Maximum 500 sq. ft.
  • Minimum size 150 sq. ft., per California Building Code for efficiency units.

Setbacks:

  • Rear and side setbacks Minimum of 4 feet.
  • Front yard setbacks Must comply with the zoning standards for the primary residence.
  • No setbacks are required for conversion ADUs (e.g., garage or accessory building conversions).

Height Limits:

  • Detached ADUs Maximum height of 16 feet.
  • Attached ADUs The same height limit as the primary residence.
  • Additional Height Allowances May be available for ADUs near transit corridors or for two-story units.

Parking Requirements:

  • No Parking Required
    • If the ADU is located within ½ mile of public transit.
    • If the ADU is part of a converted structure (e.g., garage).
    • If the ADU is in a historic district or where on-street parking permits are required.
  • If parking is required One space per unit or per bedroom, which can be tandem or in a driveway.

Owner-Occupancy:

  • For ADUs No owner-occupancy requirement for ADUs built or approved between January 1, 2020, and January 1, 2025.
  • For JADUs The property owner must live in either the JADU or the primary residence.

Utilities and Fees:

  • Utility Connections
    • Detached ADUs: May require new utility connections.
    • Attached ADUs and JADUs: Usually share existing connections.
  • Impact Fees
    • Waived for ADUs smaller than 750 sq. ft.
    • Proportional fees for larger ADUs, based on their size relative to the main residence.

Design Standards:

  • ADUs must complement the design of the primary residence, including rooflines, materials, and colors.
  • Privacy considerations include proper placement of windows and doors to reduce impacts on neighboring properties.
  • Landscaping or fencing may be required to improve privacy and aesthetics.

Permitting Process:

  • Streamlined Approval
    • Concord must approve applications within 60 days if they meet zoning and building codes.
  • Required Documentation
    • Site plan showing lot dimensions, setbacks, and ADU placement.
    • Floor plans and elevations.
    • Compliance with Concord’s building and zoning codes.

Other Considerations:

  • Affordable Housing Incentives
    • Concord may provide incentives for ADUs rented at affordable rates.
  • Historic Properties
    • Additional restrictions may apply to properties in designated historic districts.
  • Green Building Requirements
    • New detached ADUs may need to include solar panels and meet energy efficiency standards.

Next Steps:

  • Research Property Zoning
    • Use Concord’s zoning map or contact the city’s Planning Division for specific lot requirements.
  • Pre-Application Consultation
    • Engage with Concord’s Planning Division to clarify design and compliance issues.
  • Prepare Plans
    • Hire an architect or designer experienced with Concord’s ADU regulations.
  • Submit Your Application
    • Include all necessary documents, pay application fees, and await approval within the 60-day review period.
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