Accessory Dwelling Units (ADUs) in the RR-15 Rural Residential District
Accessory dwelling units are permitted in the RR-15 Rural Residential district, provided they comply with the development standards and design requirements specified in the Concord Development Code. These units are allowed in addition to a primary single-family dwelling and must adhere to specific size limitations, set back requirements, and permanent foundation mandates.
Permissibility of Accessory Dwelling Units
Accessory dwelling units are a permitted residential use on lots within the RR (Rural Residential) zoning district, which includes the RR-15 sub-designation [Section 18.200.180(C)(7)]. The RR-15 district is intended for rural single-family residential development [Section 18.30.010(A)].
General Requirements for Accessory Dwelling Units
All accessory dwelling units must meet the following requirements:
- Permit Requirement: A building permit is required for any accessory dwelling unit or junior accessory dwelling unit [Section 18.200.180(C)(1)].
- Foundation: A permanent foundation system in accordance with the Uniform Building Code is required for all accessory dwelling units [Section 18.200.180(C)(2)].
- Subdivision: Accessory dwelling units may not be sold independently of the primary dwelling but may be leased separately [Section 18.200.180(C)(4)].
- Short-Term Rentals: Accessory dwelling units cannot be rented for a term of less than 30 days [Section 18.200.180(C)(5)].
Size and Setback Standards
The size of an accessory dwelling unit is regulated based on the net area of the lot. Additionally, minimum setback requirements apply to ensure neighborhood compatibility.
| Standard | Requirement |
|---|---|
| Minimum Size | 150 square feet |
| Maximum Size (<12,000 sq. ft. lot) | 1,000 square feet (excluding up to 230 sq. ft. for attached garages/carports) |
| Maximum Size (≥12,000 sq. ft. lot) | 1,200 square feet (excluding up to 460 sq. ft. for attached garages/carports) |
| Minimum Interior Side/Rear Setback | 4 feet |
| Front/Corner-Side Setback | Must comply with primary dwelling setbacks |
Note: The size limitation is waived if it would restrict the accessory dwelling unit to less than 800 square feet [Section 18.200.180(C)(8)].
Parking Requirements
Parking for an accessory dwelling unit is required in addition to the off-street parking required for the primary single-family dwelling.
- Requirement: One off-street parking space is required per accessory dwelling unit or per bedroom, whichever is less [Section 18.200.180(C)(11)].
- Exemptions: Parking is not required if the unit is located within a one-half mile walking distance of public transit, within a designated architecturally/historically significant district, or if there is a car share vehicle site within one block [Section 18.200.180(C)(11)(b)].
Sections Cited
- Section 18.30.010: Purpose
- Section 18.200.180: Accessory dwelling units