Arlington County C-O Mixed Use District Setback Regulations
In the Arlington County C-O Mixed Use District, buildings must be set back from the centerline of any street by at least 50 feet or 50 percent of the building's height, whichever is greater. While the Arlington County zoning ordinance generally requires no side or rear yards for this district, a specific setback is triggered if the structure abuts a residential (R or RA) district or contains windows/openings, starting at 8 feet and increasing with the height of the building.
Front Setback Requirements
The placement of any building or structure within the Arlington County C-O Mixed Use District is primarily governed by its relationship to the street and its total height. The Arlington County zoning ordinance mandates a minimum distance from the street centerline to ensure adequate light, air, and safety.
| Standard Type | Requirement for C-O Mixed Use District |
|---|---|
| Street Centerline Minimum | 50 feet from the centerline of any street [§3.2.6.A.1(b)] |
| Height-Based Setback | No closer to the centerline than 50% of the total building height [§3.2.6.A.1] |
Side and Rear Setback Requirements
Under the Arlington County zoning ordinance, the C-O Mixed Use District is designed for high-density development where buildings often share property lines. However, protections are in place for neighboring residential areas and for the provision of light through windows.
| Condition | Requirement for C-O Mixed Use District |
|---|---|
| General Side or Rear Yard | 0 feet (No yard required) [§3.2.6.A.2(a)] |
| Abutting R or RA District | 8 feet for the first 10 feet of height, plus 2 feet for each additional 10 feet of height (or fraction thereof) [§3.2.6.A.2(a)] |
| Walls with Windows/Openings | 8 feet for the first 10 feet of height, plus 2 feet for each additional 10 feet of height (or fraction thereof) [§3.2.6.A.2(a)] |
Permitted Setback Encroachments
Arlington County allows certain architectural features and minor structures to extend into the required setbacks for the C-O Mixed Use District. These allowances are strictly limited to prevent excessive crowding of the public right-of-way.
Architectural Projections
- Windows and Chimneys: Bay and oriel windows without floor space, as well as chimneys, may encroach into a required yard by up to 18 inches [§3.2.6.A.3(a)(1)].
- Balconies and Eaves: Balconies, eaves, trim, and fascia boards may encroach up to four feet into a required yard, provided they remain at least five feet away from any property line [§3.2.6.A.3(a)(3)].
Mechanical and Accessory Equipment
- Air Conditioning Units: Within the Arlington County C-O Mixed Use District, mechanical equipment such as air conditioning units and heat pumps are permitted in required side or rear yards. However, they must be at least eight feet from a side lot line and 10 feet from a rear lot line. If properly screened by a fence or vegetation, they may be as close as eight feet to a street right-of-way line [§3.2.6.A.3(b)].
Special Exception and Site Plan Modifications
For developments in the C-O Mixed Use District that undergo the site plan approval process, the Arlington County Board has the authority to modify these placement and setback requirements. This is often done to achieve specific urban design goals outlined in adopted sector plans or to provide community benefits like affordable housing [§7.13.3.C, §15.5.7.A].
Sections Cited
- §3.2.6 Placement
- §7.13.3 Density and dimensional standards
- §15.5.7 Modifications and transfers