High-Density Apartment and Multiple-Family Zoning Districts in Arlington County

Arlington County permits high-density apartment buildings primarily within its Multiple-Family (RA) and high-intensity Mixed-Use (C-O) zoning districts, particularly those situated within Metrorail transit corridors. These districts allow for significant residential density, with the C-O Rosslyn district permitting a Floor Area Ratio (FAR) of up to 10.0 and the C-O-A district allowing building heights up to 216 feet via special exception site plan approval.

Residential Multiple-Family (RA) Districts

Arlington County established the RA districts to provide for varying degrees of multiple-family housing. While density is lower for by-right developments, significant increases are permitted under "Special Exception" or "Site Plan" approvals [Section 6.1.2].

RA14-26 District: Intended for multiple-family dwelling development at 14 units per acre by-right, which may increase for low-income housing [Section 6.2.3].
RA8-18 District: Provides for multiple-family dwellings with a maximum density of 36 units per acre under special exception standards [Section 6.3.4].
RA7-16 District: Allows high-density multiple-family development, with site plan approval permitting up to 100 units per acre and heights of 95 feet [Section 6.4.3].
RA6-15 District: One of the densest residential-primary districts, permitting up to 115 units per acre and building heights up to 60 feet (or higher via site plan) [Section 6.5.5].

High-Density Mixed-Use and Metro-Oriented Districts

For the highest density apartment buildings, Arlington County utilizes Mixed-Use districts that encourage high-rise development near Metrorail stations to implement the General Land Use Plan [Section 7.13.1].

RA4.8 Multiple-Family Dwelling District: Specifically designated for high-rise multiple-family dwelling redevelopment at moderate to high densities [Section 7.2.1].
R-C Multiple-family Dwelling and Commercial District: Designed for Metro station areas within a 1/4 to 1/2 mile radius of station entrances, encouraging high-medium density residential mixed-use [Section 7.3.1].
C-O-A Mixed Use District: Encourages coordinated mixed-use development including multiple-family, office, and hotel uses in the vicinity of Metrorail stations. It features some of the highest allowable heights in Arlington County [Section 7.14.1].
C-O Rosslyn and C-O Crystal City Districts: These districts are tailored for the Rosslyn and Crystal City Coordinated Redevelopment Districts. They allow the greatest density (up to 10.0 FAR in Rosslyn) to support high-rise residential towers and complex urban mixed-use projects [Section 7.15.1, Section 7.16.1].

Technical Density and Height Standards

The following table outlines the maximum density and height standards for high-density districts in Arlington County when developed via the special exception site plan process.

Density and Height by District (Site Plan Approval)

District Name	Max Density (Units/Acre or FAR)	Max Height (Stories/Feet)
RA8-18	36 units/acre	75 feet / 8 stories
RA7-16	100 units/acre	95 feet / 10 stories
RA6-15	115 units/acre	60 feet (can be increased)
RA4.8	3.24 FAR	136 feet (incl. penthouse)
R-C	3.5 FAR	95 feet (can be increased)
RA-H-3.2	4.8 FAR (incl. retail)	180 feet (incl. penthouse)
C-O-2.5	115 units/acre	16 stories
C-O	4.8 FAR	180 feet
C-O-A	6.0 FAR (for large sites)	216 feet
C-O Rosslyn	10.0 FAR	180+ feet (per sector plan)
C-O Crystal City	Per Base Density Map	300+ feet (per sector plan)

[Section 6.3.4, Section 6.4.3, Section 6.5.5, Section 7.2.3, Section 7.3.4, Section 7.5.3, Section 7.12.3, Section 7.13.3, Section 7.14.3, Section 7.15.4, Section 7.16.8]

Affordable Housing Density Bonuses

In Multiple-Family (RA) districts and various Mixed-Use districts, Arlington County may grant additional building height and density beyond the standard limits for the provision of low- or moderate-income housing [Section 15.5.9]. For example, in the RA6-15 district, the County Board may approve up to 48 units per acre (a 25% increase) if specific affordability requirements are met [Section 12.3.7].

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