Arlington County R-10T: One-family and Townhouse Dwelling District Guide
The R-10T district in Arlington County provides a transitional residential environment, allowing for single-family detached homes on 10,000-square-foot lots or larger townhouse developments with a minimum of 12 units. Townhouse projects in this district are subject to specific site plan approvals, requiring at least 1,000 square feet of common open park space per unit and a maximum building height of 36 feet [Section 5.4.1, Section 5.4.3.B].
Purpose of the R-10T District
The primary intent of the Arlington County R-10T district is to facilitate the development of one-family dwellings and, under specific conditions, townhouse projects. These townhouse developments may include a variety of styles, such as semidetached units, provided the overall project maintains a cohesive townhouse character. The R-10T district is designed to serve as a buffer or transition between lower-density one-family neighborhoods and more intensive land uses or different district classifications. A core goal of the district is to preserve natural landforms and foliage through the clustering of usable open space and well-designed living units [Section 5.4.1].
General Character and Development Rules
In the R-10T district, one-family detached dwellings are permitted by-right. However, townhouse projects are considered special exceptions and require County Board approval of a site plan. A key restriction within the Arlington County R-10T district is that while existing one-family dwellings may be retained as part of a new townhouse project, the construction of new one-family detached homes within such a project is prohibited [Section 5.4.1].
Density and Dimensional Standards
Arlington County applies different standards to the R-10T district based on whether the development is a standard one-family use or a special exception townhouse project.
| Standard Type | One-family Detached | Townhouse / Semidetached Projects |
|---|---|---|
| Minimum Lot Area | 10,000 sq. ft. | 4,300 - 5,000 sq. ft. per unit |
| Minimum Project Site Area | N/A | 51,600 sq. ft. |
| Minimum Project Units | N/A | 12 units |
| Minimum Average Lot Width | 80 feet | 18 feet per unit |
| Maximum Building Height | 35 feet | 36 feet |
| Maximum Lot Coverage | 32% | As approved by Site Plan |
[Section 3.2.5.A, Section 5.4.3]
Specific Townhouse Project Requirements
Arlington County mandates several design and site standards for R-10T townhouse developments to ensure they contribute positively to the neighborhood:
- Unit Composition: Semidetached dwellings cannot exceed one-third of the total units in the project [Section 5.4.4.A].
- Open Space: At least 1,000 square feet of the area per dwelling unit must be dedicated to common open park space. This space cannot include drives or parking areas [Section 5.4.4.A.1].
- Setbacks: Front yard setbacks must be at least 25 feet if off-street parking is provided in front of the unit. Corner lots require a minimum side yard setback of 20 feet, and all units must have a rear yard of at least 20 feet [Section 5.4.4.A.2].
- Internal Streets: Public or private internal streets must have a minimum right-of-way width of 40 feet and a minimum pavement width of 30 feet [Section 5.4.4.A.5].
Permitted Land Uses
The R-10T district primarily supports residential uses but allows for certain civic and institutional activities.
Residential Uses
- One-family detached: Permitted by-right [Section 5.1.2].
- Townhouses and Semidetached: Permitted by special exception [Section 5.1.2].
- Recovery Residences: Permitted by-right if serving eight or fewer residents [Section 5.1.2, Section 12.3.9].
- Accessory Dwellings: Permitted as an accessory use [Section 5.1.4].
Public, Civic, and Institutional Uses
Most institutional uses in the R-10T district require a use permit or special exception:
- Churches, mosques, synagogues, and temples: Permitted by-right [Section 5.1.2].
- Schools (Elementary, Middle, High): Requires a use permit [Section 5.1.2].
- Hospitals and Libraries: Requires a use permit [Section 5.1.2].
- Community Centers and Swimming Pools: Requires a use permit [Section 5.1.2].
Parking Requirements
Parking in the Arlington County R-10T district is calculated based on the specific use type to prevent congestion on local streets.
| Use Type | Minimum Parking Requirement |
|---|---|
| One-family (Not on cul-de-sac) | 1 space per dwelling unit |
| One-family (Fronting cul-de-sac) | 2 spaces per dwelling unit |
| Townhouses | 2.5 off-street spaces per dwelling unit |
| Religious Institutions | 1 space per 5 sanctuary seats |
[Section 5.4.4.A.7, Section 14.3.7.A]
Sections Cited
- Section 3.2.5. Coverage
- Section 5.1.2. Residential (R) districts principal use table
- Section 5.1.4. Residential (R) districts accessory use table
- Section 5.4.1. R-10T Purpose
- Section 5.4.3. R-10T Density and dimensional standards
- Section 5.4.4. R-10T District use standards
- Section 12.3.9. Recovery Residences
- Section 14.3.7.A. Required parking and standing space