Accessory Dwelling Units in the RL (Low Density Residential) District
In the RL (Low Density Residential) District of the City of Concord, accessory dwelling units are a permitted residential use. Homeowners may develop an accessory dwelling unit on a lot that contains an existing or proposed single-family principal dwelling, provided the unit meets specific size, design, and development standards set forth in the Concord Development Code.
Permissibility of Accessory Dwelling Units
Accessory dwelling units are explicitly permitted in the R (Residential) District, which includes the RL (Residential Low Density) zoning designation [Section 18.200.180(C)(7)]. These units provide independent living facilities for one or more persons and include permanent provisions for living, sleeping, eating, cooking, and sanitation [Section 18.200.180(B)].
Development and Design Standards
Accessory dwelling units in the RL District must comply with the general requirements for accessory dwelling units, except where specific exceptions apply.
Size and Height Limitations
The size of an accessory dwelling unit is limited by the following standards:
| Standard | Requirement |
|---|---|
| Minimum Living Area | 150 square feet |
| Maximum Size (General) | Lesser of 50% of the principal dwelling floor area or 1,000 square feet (for lots < 12,000 sq. ft.) / 1,200 square feet (for lots ≥ 12,000 sq. ft.) |
| Maximum Size (Waived) | If size limitations restrict the unit to less than 800 square feet, the limitation is waived |
For height, detached accessory dwelling units in the RL District are generally limited to 16 feet, though this may be increased to 18 feet under specific conditions related to transit proximity or if the lot features an existing multistory principal dwelling [Section 18.200.180(C)(17)].
Setbacks
Accessory dwelling units in the RL District must adhere to the following setback requirements:
| Setback Type | Minimum Requirement |
|---|---|
| Interior Side Setback | 4 feet |
| Rear Setback | 4 feet |
| Front/Corner Side Setback | Must comply with principal dwelling requirements |
Parking Requirements
Parking for an accessory dwelling unit is in addition to the requirements for the principal dwelling, but exemptions may apply [Section 18.200.180(C)(11)].
- Requirement: One off-street parking space is required per accessory dwelling unit or per bedroom, whichever is less.
- Parking Exemptions: Parking is not required if the accessory dwelling unit is located within one-half mile walking distance of public transit, is part of an existing structure, or is located within a designated architecturally and historically significant historic district.
General Requirements
- Short-Term Rentals: Accessory dwelling units cannot be rented for terms of less than 30 days [Section 18.200.180(C)(5)].
- Subdivision: Accessory dwelling units cannot be sold independently of the principal dwelling [Section 18.200.180(C)(4)].
- Design: For units that are not pre-approved, exterior materials, roof pitch, and colors must be consistent with the principal dwelling [Section 18.200.180(C)(10)].
Sections Cited
- Section 18.200.180 (Accessory dwelling units)