Accessory Dwelling Unit Regulations for RS-7.5 Residential Zoning
In the City of Concord, Accessory Dwelling Units (ADUs) are permitted by right in the RS-7.5 (Single-Family Residential) district as an accessory use to a single-family principal dwelling. These units must comply with specific size, design, and development standards, though certain size limitations may be waived if they restrict the ADU to less than 800 square feet [Section 18.200.180].
Permitted Zoning Districts
Accessory Dwelling Units are allowed in zoning districts that permit single-family or multifamily principal dwelling residential uses. The RS-7.5 (Residential Single-Family) district is explicitly included in this authorization [Section 18.200.180].
Development Standards for Accessory Dwelling Units
The following standards apply to the development of Accessory Dwelling Units in the RS-7.5 district:
| Standard | Requirement |
|---|---|
| Minimum Living Area | 150 square feet |
| Maximum Size | Lesser of 50% of the principal dwelling floor area or 1,000 sq. ft. (on lots < 12,000 sq. ft.) |
| Setbacks (Interior Side/Rear) | Minimum of 4 feet |
| Height (Attached ADU) | Maximum 25 feet (or the height limit of the principal dwelling, whichever is lower) |
| Height (Detached ADU) | Maximum 16 feet (standard) or 18 feet (if within 0.5 miles of a major transit stop) |
| Parking | 1 off-street space per ADU or per bedroom (whichever is less) |
Note: The size limitation is waived if it would restrict the Accessory Dwelling Unit to less than 800 square feet [Section 18.200.180].
Parking Requirements and Exemptions
Parking for an Accessory Dwelling Unit is required in addition to the off-street parking for the principal dwelling. However, the City of Concord permits parking exemptions for Accessory Dwelling Units in the following instances:
- The Accessory Dwelling Unit is located within one-half mile walking distance of public transit.
- The Accessory Dwelling Unit is located within a designated architecturally and historically significant historic district.
- The Accessory Dwelling Unit is part of the proposed or existing principal dwelling or a conversion of an existing accessory structure.
- On-street parking permits are required but not offered to the occupant of the Accessory Dwelling Unit.
- A car share vehicle site is located within one block of the Accessory Dwelling Unit [Section 18.200.180].
Design and Operational Standards
- Short-Term Rentals: Accessory Dwelling Units shall not be rented for a term of less than 30 days [Section 18.200.180].
- Subdivision: No subdivision of land or air rights is allowed that would result in the Accessory Dwelling Unit existing on a separate lot from the principal dwelling. The unit may not be sold independently of the principal dwelling [Section 18.200.180].
- Building Permits: A building permit application for an Accessory Dwelling Unit in the RS-7.5 district will be ministerially processed within 60 days of receipt of a complete application [Section 18.200.180].
Sections Cited
- Section 18.200.180 (Accessory dwelling units)