C-O-2.5 Mixed Use District: Arlington County Zoning Guide
The C-O-2.5 Mixed Use District in Arlington County is a high-density zone designed for high-rise redevelopment projects that integrate office, hotel, commercial, and multi-family residential uses. Under special exception provisions, building heights in the C-O-2.5 district can reach up to 16 stories, with residential densities allowed up to 115 units per acre and hotel densities up to 180 units per acre [Section 7.12.1, Section 7.12.3.B].
Purpose of the C-O-2.5 District
The primary purpose of the C-O-2.5 Mixed Use District within Arlington County is to provide for limited office building land use. Additionally, under appropriate conditions, the district encourages the high-rise redevelopment of specific areas into a mix of office buildings, hotels, commercial entities, and multiple-family dwellings [Section 7.12.1]. This district is specifically intended for application within planning districts as designated on the Arlington County General Land Use Plan [Section 7.12.1].
General Character
The general character of the C-O-2.5 district is defined by its "Mixed Use" designation, promoting a vertical or horizontal blend of residential and commercial activities. Determinations regarding the actual types and densities of allowed uses are based on the specific characteristics of individual sites, their neighborhood context, and the community's need for facilities, open space, circulation, and utilities [Section 7.12.1]. By site plan approval, Arlington County allows buildings to have a mix of uses, though no part of a site may be counted more than once when calculating permitted density [Section 7.12.4.A].
Density and Dimensional Standards
Arlington County specifies distinct standards for "by-right" development versus "special exception" development (which typically involves a site plan approval) in the C-O-2.5 district.
By-Right Development Standards
Development permitted by-right in the C-O-2.5 district must adhere to the following area and height requirements:
| Type of Standard | One-family Dwelling | All Other By-Right Uses |
|---|---|---|
| Minimum Lot Area | 6,000 sq. ft. | 20,000 sq. ft. |
| Minimum Lot Width | 60 feet | 100 feet |
| Maximum Height | 35 feet | 35 feet |
| Max FAR (Site < 9,999 sq. ft.) | N/A | 0.40 |
| Max FAR (Site 10,000–19,999 sq. ft.) | N/A | 0.50 |
| Max FAR (Site 20,000+ sq. ft.) | N/A | 0.60 |
[Section 7.12.3.A]
Special Exception Development Standards
When approved by the County Board as a special exception, the C-O-2.5 district allows for significantly increased density and height:
| Type of Standard | Office/Commercial | Multiple-family | Hotel |
|---|---|---|---|
| Max Density | 2.5 FAR | 115 units/acre | 180 units/acre |
| Minimum Lot Area | 20,000 sq. ft. | 20,000 sq. ft. | 20,000 sq. ft. |
| Minimum Lot Width | 100 feet | 100 feet | 100 feet |
| Max Height (Stories) | 12 stories | 16 stories | 16 stories |
[Section 7.12.3.B]
Permitted Land Uses
Permitted uses in the C-O-2.5 district are governed by the Commercial/Mixed Use principal use table. Most high-density uses in this Arlington County district require site plan ("S") approval [Section 7.1.2].
Residential Uses
- One-family detached: Permitted by-right.
- Multiple-family: Allowed by site plan approval.
- Group Living: Assisted living facilities, continuing care retirement communities, and nursing homes are allowed by site plan approval [Section 7.1.2].
Commercial and Retail Uses
- General Retail: Bakeries, drug stores, florists, and grocery stores are allowed via site plan approval.
- Food Establishments: Restaurants and artisan beverage facilities are allowed via site plan approval.
- Office: Medical, dental, professional, and local government offices are permitted via the site plan process.
- Hospitality: Hotels and motels are allowed via site plan approval [Section 7.1.2].
Site Development and Parking
All development in the C-O-2.5 district must comply with the general site development standards of Arlington County, including those for signs (Article 13) and landscaping (Article 14) [Section 7.12.5].
Parking requirements are generally calculated as specified in Section 14.3, though specific requirements may be modified within an approved site plan [Section 7.12.5.A].
| Use Type | Minimum Parking Requirement |
|---|---|
| Multiple-family Dwelling | 1 & 1/8 spaces for each of the first 200 units; 1 space per unit thereafter. |
| Office Buildings | 1 per 250 sq. ft. of floor area on the 1st floor; reduced ratios for higher floors. |
| Hotel | 0.7 off-street parking spaces for each guest room and dwelling unit. |
[Section 14.3.7]
Sections Cited
- §7.1. Commercial/Mixed Use (C) Districts Use Tables
- §7.12. C-O-2.5, Mixed Use District
- §14.3.7. Required parking and standing space