RA6-15 Multiple-family Dwelling District Setback Standards in Arlington County
In the RA6-15 Multiple-family Dwelling district in Arlington County, front setbacks for multi-family buildings must be the greater of 25 feet from the street right-of-way or 50 feet from the street centerline. Side setbacks for these structures start at 10 feet and increase by one foot for every 2.5 feet of building height above 25 feet, while rear setbacks for interior lots are fixed at a minimum of 25 feet [Section 3.2.6.A].
General Setback Requirements by Use Type
The RA6-15 district in Arlington County allows for several residential use types, including one-family detached dwellings, two-family dwellings, townhouses, and multi-family apartments. Setback requirements (referred to as "required yards" in the Arlington County Zoning Ordinance) vary depending on the specific use established on the lot [Section 6.5.5].
RA6-15 Minimum Setback Standards Table
| Use Type | Front Setback (from Street ROW) | Side Setback (Minimum) | Rear Setback (Minimum) |
|---|---|---|---|
| Multi-family / Apartment | 25 feet (or 50 feet from centerline, whichever is larger) | 10 feet + 1 foot for every 2.5 feet of height over 25 feet | 25 feet |
| Townhouse | 25 feet (or 50 feet from centerline, whichever is larger) | 10 feet + 1 foot for every 2.5 feet of height over 25 feet | 25 feet |
| One-family Detached | 25 feet (may be reduced to frontage average) | 10 feet (one side may be reduced to 8 feet) | 25 feet |
| Two-family (Duplex) | 25 feet (may be reduced to frontage average) | 10 feet + 1 foot for every 2.5 feet of height over 25 feet | 25 feet |
Specific Placement Regulations for the RA6-15 District
Front Setback and Centerline Rules
For multi-family residential structures in the RA6-15 district, Arlington County prohibits any structure from being located closer than 50 feet to the centerline of any street or officially designated street right-of-way. Additionally, these structures must maintain a minimum distance of 25 feet from the street right-of-way line [Section 3.2.6.A.1].
If a one-family or two-family dwelling is built within the RA6-15 district, the front wall may be placed at a distance equal to the average of the distances between the street right-of-way and the edges of the front walls of existing structures on that frontage, provided it is at least 15 feet from the line [Section 3.2.6.A.1(e)].
Height-Adjusted Side Setbacks
For any residential building in the RA6-15 district other than a one-family dwelling, Arlington County utilizes a sliding scale for side yards. The base setback is 10 feet. For every 2.5 feet of building height (or fraction thereof) exceeding 25 feet, the building must be set back an additional one foot [Section 3.2.6.A.2(e)].
For example, a multi-family building in the RA6-15 district at its maximum height of 60 feet would have a side setback of 24 feet (10 feet base + 14 feet for the 35 feet of height above the 25-foot threshold) [Section 6.5.5.A, Section 3.2.6.A.2(e)].
Rear Setback Standards
Arlington County requires that no structure in the RA6-15 district be located closer than 25 feet from a rear lot line on interior lots. This 25-foot requirement applies to one-family dwellings, multi-family buildings, and other residential structures [Section 3.2.6.A.2].
Permitted Encroachments into Required Yards
Certain architectural features are permitted to project into the required setbacks for the RA6-15 district:
- Architectural Features: Bay windows (without floor space) and chimneys may encroach up to 18 inches into any required yard [Section 3.2.6.A.3(a)].
- Unenclosed Features: Balconies, eaves, trim, decks, patios (at least 8 inches above grade), and stoops may encroach up to four feet into required yards, provided they remain at least five feet from any property line [Section 3.2.6.A.3(a)].
- Front/Rear Porches: On interior lots, porches may encroach four feet into required front and rear yards but must be at least 21 feet from any street right-of-way line [Section 3.2.6.A.3(a)].
Visual Clearance at Corners
For corner lots in the RA6-15 district, Arlington County mandates a clear sight triangle. There shall be no structures, plantings, or fences between the heights of three feet and 10 feet above the curb level within the triangle formed by the street right-of-way lines and a line connecting those lines 25 feet from their intersection [Section 3.2.6.A.4].
Sections Cited
- Section 3.2.6. Placement
- Section 3.2.6.A.1. Setbacks from any street
- Section 3.2.6.A.2. Side and rear yards
- Section 3.2.6.A.3. Encroachments allowed into required yards and courts
- Section 3.2.6.A.4. Visual clearance (corners)
- Section 6.5.5. RA6-15 Density and dimensional standards
- Section 12.3.4. Townhouse, semidetached and existing one-family