Arlington County C-1-O: Limited Commercial-Professional Office Building District Guide
The C-1-O district in Arlington County is designed to accommodate low-intensity professional offices and financial institutions while strictly maintaining a residential aesthetic. Development within the Arlington County C-1-O district requires a minimum lot area of 20,000 square feet for non-residential uses and mandates that buildings do not exceed 35 feet in height.
Purpose of the C-1-O District
Arlington County established the C-1-O district to provide designated areas for non-retail commercial activities. The primary intent is to allow for the development of professional offices and financial institutions in a low-intensity manner that remains compatible with surrounding residential environments [§7.9.1].
General Character and Building Type
The most distinct characteristic of the Arlington County C-1-O district is the mandatory "residential appearance" for all structures. Every building erected in the C-1-O district must feature an exterior design that presents the appearance of a residential structure. Zoning authorities evaluate the exterior design based on how closely the building’s bulk and placement comply with the requirements for residential buildings in the immediate vicinity [§7.9.5].
Permitted Land Uses
Arlington County permits a specific mix of residential, professional, and civic uses in the C-1-O district, categorized by their approval process [§7.1.2].
By-Right Uses (Permitted)
The following uses are allowed in the C-1-O district without a special exception, provided they meet all standards:
- Residential: One-family detached dwellings and recovery residences (for 8 or fewer residents).
- Office and Financial: Business and professional offices, medical or dental offices/clinics, financial services, and local government offices.
- Civic: Fire and police stations, and churches/places of worship.
- Other: Urban agriculture, urban colleges and universities, and minor utilities.
Special Exception Uses
Certain uses require specific approval from Arlington County through Use Permits (U), Site Plan approval (S), or a combination of both (C):
- Use Permit Required (U): Colleges and universities, community centers, libraries, child care centers, and major utilities.
- Site Plan Required (S): Hospitals, independent living facilities, assisted living facilities, and nursing homes.
- Site Plan and Use Permit Required (C): Mortuaries and funeral homes.
Density and Dimensional Standards
Development in the Arlington County C-1-O district must adhere to specific lot and height requirements to ensure the low-intensity character of the neighborhood is preserved [§7.9.3, §3.2.5.B].
| Type of Standard | One-Family Dwellings | All Other Allowed Uses |
|---|---|---|
| Minimum Lot Area | 6,000 sq. ft. | 20,000 sq. ft. |
| Minimum Lot Width | 60 feet | 100 feet |
| Maximum Building Height | 35 feet | 35 feet |
| Maximum Lot Coverage | As per District Table (§3.2.5.A) | 56 percent |
Floor Area Ratio (FAR)
For non-residential developments in the C-1-O district, the maximum density is governed by the total site area [§7.9.3.A]:
| Site Area | Maximum Floor Area Ratio (FAR) |
|---|---|
| Up to 9,999 sq. ft. | 0.40 |
| 10,000 to 19,999 sq. ft. | 0.50 |
| 20,000 sq. ft. and above | 0.60 |
Site Development Standards
Landscaping Requirements
In the C-1-O district, Arlington County requires a high level of open space to maintain the residential feel. A minimum of 20 percent of the total site area must be dedicated to landscaped open space [§7.9.6.A].
Parking and Loading
Arlington County mandates off-street parking based on the specific use within the C-1-O district [§14.3.7]:
- General Office Buildings: One space per 250 sq. ft. of floor area on the first floor; one per 300 sq. ft. for the second through fifth floors.
- Medical/Dental Offices: One space per 150 sq. ft. for the first 5,000 sq. ft. of the building.
- One-Family Dwellings: One space per dwelling unit (or two if fronting on a cul-de-sac).
Sections Cited
- §1.7.1 General districts
- §3.2.5 Coverage
- §7.1.2 Commercial/Mixed Use (C) Districts Principal Use Table
- §7.9.1 C-1-O Purpose
- §7.9.2 C-1-O Uses
- §7.9.3 C-1-O Density and dimensional standards
- §7.9.5 C-1-O Use limitations
- §7.9.6 C-1-O Site development standards
- §14.3.7 Required parking and standing space
- §18.2 General Terms Defined