Arlington County C-O-A Mixed Use District Setback Requirements
In the C-O-A: Mixed Use district of Arlington County, commercial and mixed-use structures are primarily governed by a front setback of 40 feet from the street centerline. Side and rear setbacks are generally not required for this district unless the building wall includes windows or directly abuts a residential (R or RA) district, at which point a graduated setback starting at 8 feet is required based on total building height [§3.2.6.A.2].
Front Setback Requirements
The front setback for the C-O-A: Mixed Use district in Arlington County depends on the type of structure being developed. Most commercial, hotel, and multiple-family buildings fall under the general standard for "C" districts, while specific one-family dwellings that may exist in the district follow different residential standards.
| Structure Type | Front Setback Requirement | Reference |
|---|---|---|
| General Commercial / Mixed-Use | 40 feet from the street centerline | [§3.2.6.A.1(a)] |
| One-family Detached Dwellings | 25 feet from the street right-of-way line | [§3.2.6.A.1(e)] |
Front Setback Exceptions for One-Family Dwellings
For one-family dwellings in the C-O-A: Mixed Use district, the front wall setback may be reduced to the average distance of the edges of front walls of existing structures located on the same frontage, provided the distance is at least 15 feet. However, no parking garage can be located closer than 18 feet from the street right-of-way line [§3.2.6.A.1(e)].
Side and Rear Setback Requirements
In the Arlington County C-O-A: Mixed Use district, side and rear yards are not mandatory for commercial or mixed-use structures unless specific "trigger" conditions are met.
| Condition | Side / Rear Setback Requirement | Reference |
|---|---|---|
| General (No windows/No residential buffer) | None (0 feet) | [§3.2.6.A.2(a)] |
| Wall contains windows or openings | Graduated (8 feet minimum) | [§3.2.6.A.2(a)] |
| Wall abuts an R or RA district | Graduated (8 feet minimum) | [§3.2.6.A.2(a)] |
| One-family Detached Dwellings | 10 feet (one side may be reduced to 8 feet) | [§3.2.6.A.2(b)] |
Graduated Setback Calculation
When a side or rear setback is triggered by the presence of windows or an abutting residential district in the C-O-A: Mixed Use district, the width of the yard must increase as the building height increases.
| Building Height | Required Side/Rear Setback |
|---|---|
| 0 to 10 feet | 8 feet |
| 10 to 20 feet | 10 feet |
| 20 to 30 feet | 12 feet |
| Each additional 10 feet | Add 2 feet to the setback |
Additional Placement Regulations
Corner Visual Clearance
Arlington County requires that corner lots in the C-O-A: Mixed Use district maintain a "sight triangle" to ensure traffic safety. Within a triangle formed by the street right-of-way lines and a line connecting those lines 10 feet from their intersection, no building or obstructions are permitted between a height of one foot and 10 feet higher than the curb level [§3.2.6.A.4(b)].
Setback Encroachments
Specific architectural features are permitted to encroach into the required setbacks of the C-O-A: Mixed Use district:
- 18 Inches: Bay and oriel windows (without floor space) and chimneys [§3.2.6.A.3(a)(1)].
- 4 Feet: Balconies, eaves, trim, decks, and patios (8 inches or higher above grade), and stoops [§3.2.6.A.3(a)(3)].
Sections Cited
- §3.2.6.A.1 Setbacks from any street
- §3.2.6.A.2 Side and rear yards
- §3.2.6.A.3 Encroachments allowed into required yards and courts
- §3.2.6.A.4 Visual clearance (corners)
- §7.14 C-O-A, Mixed Use District