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Accessory Dwelling Units in the RS-7 Zoning District

Jurisdiction: ConcordCode Version: February 10, 2026

In the City of Concord, an Accessory Dwelling Unit (ADU) is a permitted use in the RS-7 (Single-Family Residential) zoning district, subject to specific development standards and building permit requirements. These units are allowed in addition to a primary single-family residence and must comply with the design, size, and parking regulations established in the Concord Development Code.

Permissibility of Accessory Dwelling Units in RS-7

The RS-7 district, classified under the "Single-Family Residential" category, allows for the establishment of Accessory Dwelling Units [Section 18.30.010]. Accessory dwelling units in the RS-7 district are not considered to exceed the allowable density for a lot [Section 18.200.180(C)(3)].

General Development Standards for Accessory Dwelling Units

Accessory dwelling units in the RS-7 district must adhere to the following development standards:

Standard Requirement
Minimum Living Area 150 square feet [Section 18.200.180(C)(8)]
Maximum Living Area Lesser of 50% of the primary dwelling's floor area or 1,000 square feet (on lots < 12,000 sq. ft.) [Section 18.200.180(C)(8)]
Interior Side/Rear Setback Minimum 4 feet [Section 18.200.180(C)(16)]
Height (Attached) Maximum 25 feet or the height of the primary dwelling, whichever is lower [Section 18.200.180(C)(17)]
Height (Detached) Generally 16 feet (some exceptions up to 18 feet near transit) [Section 18.200.180(C)(17)]
Parking Requirement 1 off-street space per unit or per bedroom (whichever is less) [Section 18.200.180(C)(11)]

Design and Operational Requirements

  • Rental Restrictions: Accessory dwelling units in the RS-7 district may not be rented for terms of less than 30 days [Section 18.200.180(C)(5)].
  • Subdivision Prohibition: Accessory dwelling units cannot be sold independently of the primary single-family residence on the same lot [Section 18.200.180(C)(4)].
  • Design Consistency: Unless an accessory dwelling unit is pre-approved by the City of Concord, it must maintain exterior colors and materials consistent with the primary residence [Section 18.200.180(C)(10)].

Parking Exemptions

Parking for an accessory dwelling unit is not required in the RS-7 district if the unit meets one of the following criteria [Section 18.200.180(C)(11)]:

  1. Located within a one-half mile walking distance of public transit.
  2. Located within a designated architecturally and historically significant historic district.
  3. Part of the proposed or existing primary dwelling or a conversion of an existing accessory structure.
  4. Located where on-street parking permits are required but not offered to the occupant of the accessory dwelling unit.
  5. Located within one block of a car share vehicle site.

Sections Cited

  • Section 18.30.010 (Purpose - Residential Districts)
  • Section 18.200.180 (Accessory dwelling units)

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Accessory Dwelling Units in the RS-7 Zoning District | Concord Zoning Guide