Maximum Lot Coverage Standards for Arlington County Residential Properties
Maximum lot coverage for one-family dwellings in Arlington County ranges from 25% in R-20 districts to 45% in R-5 districts, with specific increases allowed for properties featuring front porches or detached rear garages. For residential lots used for purposes other than one-family dwellings, the Arlington County Zoning Ordinance generally caps lot coverage at 56%. Expanded Housing Option developments and residential clusters follow specialized coverage limits ranging between 30% and 50% depending on the specific zoning district.
Definition of Lot Coverage in Arlington County
In Arlington County, lot coverage is defined as the percentage of the total lot area occupied by specific structures and surfaces. This is calculated by dividing the total square footage of all regulated features by the gross area of the lot [§3.1.4.A.1].
Regulated features included in the Arlington County lot coverage calculation include:
- The main building footprint [§3.1.4.A.1(a)].
- Total footprints of accessory buildings larger than 150 square feet or more than two stories in height [§3.1.4.A.1(b)].
- Driveways and parking pads, whether paved or unpaved [§3.1.4.A.1(c)].
- Patios eight inches or higher above finished grade [§3.1.4.A.1(d)].
- Decks four feet or higher from finished grade that are not attached to the main building [§3.1.4.A.1(e)].
- Gazebos, pergolas, in-ground swimming pools, and certain stoops or landings [§3.1.4.A.1(f)-(h)].
Arlington County expressly excludes certain items from coverage calculations, such as air conditioners, above-ground swimming pools, hot tubs, and standard sidewalks or pedestrian walkways [§3.1.4.A.2].
General Residential Coverage Standards
The Arlington County Zoning Ordinance establishes maximum lot coverage based on the specific residential district. One-family dwellings are subject to a sliding scale, while other residential uses in these districts are generally permitted higher coverage.
One-Family Dwelling Maximum Coverage
The following table outlines the maximum percentages permitted for one-family dwellings in Arlington County residential districts [§3.2.5.A]:
| District | Standard Maximum Lot Coverage (%) | Max Coverage with Front Porch* (%) | Max Coverage with Detached Rear Garage (%) | Max Coverage with Porch AND Rear Garage (%) |
|---|---|---|---|---|
| R-5, R15-30T | 45% | 48% | 50% | 53% |
| R-6, R2-7, RA, C, M | 40% | 43% | 45% | 48% |
| R-8 | 35% | 38% | 40% | 43% |
| R-10, R-10T | 32% | 35% | 37% | 40% |
| R-20 | 25% | 28% | 30% | 33% |
*Note: The porch must be at least 60 square feet (excluding wrap-around portions) on the front elevation to qualify for the increased coverage allowance [§3.2.5.A].
Coverage for Other Residential Uses
For lots in R, RA, R2-7, and C-1-O districts that are not utilized for one-family dwellings, Arlington County limits lot coverage to a maximum of 56%. This limit applies unless a different specification is made within a specific district classification or modified via a site plan or use permit [§3.2.5.B].
Coverage for Unified and Specialized Developments
Arlington County provides specific lot coverage rules for non-traditional residential developments, such as clusters or expanded housing options.
Expanded Housing Option (EHO) Development
For Expanded Housing Option developments (which may include duplexes, semidetached units, or small multi-family structures up to 6 units), Arlington County applies the following maximum lot coverage standards [§10.4.4.C]:
| District | Maximum Lot Coverage (%) | Max Coverage with Front Porch (%) |
|---|---|---|
| R-5 | 50% | 53% |
| R-6 | 45% | 48% |
| R-8 | 40% | 43% |
| R-10 | 37% | 40% |
| R-20 | 30% | 33% |
Residential Cluster and Special Districts
- Residential Cluster Developments: In Arlington County, every residential cluster development is limited to a maximum coverage (including buildings, rights-of-way, and drives) of 50% of the total site area [§10.3.7.B].
- S-D (Special Development) District: One-family dwellings in the S-D district are permitted a maximum lot coverage of 56% [§4.3.3.A].
- Clarendon Revitalization District (C-3): Lot coverage for special exceptions in this district is generally limited to 80% on blocks with height limits of 75 feet or less, and 65% on blocks where heights exceed 75 feet [§9.2.2.D.6].
Sections Cited
- §3.1.4 Coverage
- §3.2.5 Coverage
- §4.3.3 Density and dimensional standards (S-D District)
- §9.2.2 C-3 District (Clarendon Revitalization District)
- §10.3.7 Density and dimensional standards (Residential Cluster Development)
- §10.4.4 Density and dimensional standards (Expanded Housing Option Development)