R-10 One-family Dwelling District: Arlington County Zoning Guide
The R-10 One-family Dwelling District in Arlington County is designed primarily for single-family detached residences on lots with a minimum area of 10,000 square feet and a minimum width of 80 feet. This district maintains a low-density residential character while permitting limited institutional and accessory uses, typically requiring a minimum of one off-street parking space per dwelling unit.
Purpose and General Character
The Arlington County Zoning Ordinance establishes the R-10 district as part of its residential (R) district groupings [§1.7.1]. While the specific purpose statement for the district is reserved, its character is defined by large-lot residential development intended for one-family detached dwellings [§5.3.1]. The district emphasizes a suburban-style environment with significant yard requirements and regulated building coverage to ensure open space and neighborhood compatibility [§3.2.1].
Density and Dimensional Standards
Development within the Arlington County R-10 district must adhere to strict bulk and placement requirements. The standard minimum lot size is 10,000 square feet, though specific exceptions exist for "split-lot" developments.
R-10 District Standard Requirements
| Type of Standard | Requirement |
|---|---|
| Minimum Lot Area | 10,000 sq. ft. [§5.3.3.A] |
| Minimum Lot Area per Dwelling Unit | 10,000 sq. ft. [§5.3.3.A] |
| Minimum Average Lot Width | 80 feet [§5.3.3.A] |
| Maximum Building Height | 35 feet [§5.3.3.A] |
| Minimum Front Yard Setback | 25 feet [§3.2.6.A.1(e)] |
| Minimum Side Yard Setback | 10 feet (one side may be reduced to 8 feet) [§3.2.6.A.2(b)] |
Maximum Lot and Footprint Coverage
Arlington County regulates how much of an R-10 lot can be covered by buildings and other features to preserve permeable surfaces and open space.
| Category | Maximum Coverage Percentage |
|---|---|
| Maximum Lot Coverage | 32% [§3.2.5.A] |
| Coverage with front porch (min. 60 sq. ft.) | 35% [§3.2.5.A] |
| Coverage with detached rear garage | 37% [§3.2.5.A] |
| Coverage with both porch and detached garage | 40% [§3.2.5.A] |
| Main building footprint coverage | 25% [§3.2.5.A] |
Permitted and Conditional Uses
The R-10 district in Arlington County primarily allows residential uses by-right, while most civic or institutional uses require a special exception via a use permit (U) or site plan (S) approval.
Residential Uses
- One-family detached dwellings: Permitted by-right [§5.1.2].
- Recovery Residences: Permitted by-right for eight or fewer residents [§12.3.9].
- Accessory Dwellings: Allowed subject to specific standards and a permit from the zoning administrator [§12.9.2].
- Group Homes: Allowed via use permit approval [§5.1.2].
Civic and Institutional Uses (Use Permit Required)
Many non-residential uses are allowed in the R-10 district to serve the community, provided they obtain a use permit (U) and meet specific standards:
- Schools (Elementary, Middle, and High) [§5.1.2].
- Churches, mosques, synagogues, and temples [§5.1.2].
- Libraries, museums, and community centers [§5.1.2].
- Hospitals and nursing homes [§5.1.2].
Site Development Standards
Parking
In the Arlington County R-10 district, one-family detached dwellings require one parking space per dwelling unit [§14.3.7]. If the lot fronts a cul-de-sac, the requirement increases to two parking spaces per dwelling unit. For accessory dwellings, additional parking may be required unless a parking survey demonstrates that the block is less than 65% parked [§14.3.7].
Split-Lot Residential Development
Arlington County allows for "split-lots" in the R-10 district as an alternative to pipe-stem development. To qualify, the original site must have a minimum frontage of 120 feet. The resulting lots must have a minimum width of 60 feet [§3.2.4.C.1].
Sections Cited
- §1.7.1 Zoning Districts Established
- §3.2.1 Purpose (Bulk, Coverage and Placement)
- §3.2.4.C Split-lot Exceptions
- §3.2.5.A Coverage (One-family dwellings)
- §3.2.6.A Setbacks
- §5.1.2 Residential (R) Districts Principal Use Table
- §5.3 R-10, One-Family Dwelling District
- §12.3.9 Recovery Residences
- §12.9.2 Accessory Dwellings
- §14.3.7 Required parking and standing space