Setback Requirements for M-1 Light Industrial Districts in Arlington County

In the Arlington County M-1: Light Industrial district, structures must maintain a minimum front setback of 40 feet from the centerline of any street. While the Arlington County zoning ordinance generally does not require side or rear yards for this district, specific setbacks are mandatory when a building contains windows or openings, or when the lot abuts a residential (R or RA) district. In these instances, the side and rear setbacks begin at 8 feet for the first 10 feet of building height and increase based on the total height of the structure.

M-1 District Setback Standards

The following table outlines the primary placement and yard requirements for properties located within the M-1: Light Industrial district in Arlington County [Section 8.3.3, Section 3.2.6].

Type of Setback	Requirement
Front (Street)	40 feet from the centerline of any street [Section 3.2.6.A.1]
Side Yard (Standard)	None required [Section 3.2.6.A.2]
Rear Yard (Standard)	None required [Section 3.2.6.A.2]
Side/Rear (Abutting R/RA)	8 feet for the first 10 feet of height + 2 feet for every additional 10 feet of height [Section 3.2.6.A.2]
Side/Rear (With Windows)	8 feet for the first 10 feet of height + 2 feet for every additional 10 feet of height [Section 3.2.6.A.2]

Front Setback Requirements

The primary setback for the M-1 district is measured from the street. Arlington County regulations state that no structure in an industrial district may be located closer than 40 feet to the centerline of any street [Section 3.2.6.A.1]. Additionally, no structure shall be located closer to the centerline of any street than 50 percent of the height of the building [Section 3.2.6.A.1].

Side and Rear Yard Requirements

For most industrial developments in the M-1 district, Arlington County does not mandate a minimum side or rear yard. However, there are two critical exceptions where a setback is required [Section 3.2.6.A.2]:

Abutting Residential Districts: If any wall of a structure in the M-1 district abuts a Residential (R) or Residential Apartment (RA) district, a setback is required.
Wall Openings: If a wall contains openings or windows (regardless of whether they can be opened), a setback is required.

In these cases, the building must be set back at least 8 feet for the first 10 feet of building height. For every additional 10 feet of building height (or fraction thereof), an additional 2 feet must be added to the setback distance [Section 3.2.6.A.2].

Corner Lot Visual Clearance

Arlington County mandates specific visual clearance at street intersections to ensure traffic safety. On corner lots within the M-1 district, no buildings or obstructions are permitted between a height of one foot and 10 feet above the curb level within the "sight triangle" [Section 3.2.6.A.4]. This triangle is formed by the street right-of-way lines and a diagonal line connecting those points 10 feet from the intersection [Section 3.2.6.A.4].

Permitted Encroachments

Certain architectural features are allowed to extend into the required setbacks or yards in the M-1 district, including [Section 3.2.6.A.3]:

Architectural Features: Eaves, trim, fascia boards, and similar items may encroach up to 4 feet, provided they are no closer than 5 feet to any property line.
Windows and Chimneys: Bay windows, oriel windows (without floor space), and chimneys may encroach up to 18 inches.
Stairs: Uncovered stairs and steps may encroach into required yards but must remain at least 5 feet from any lot line.
Fences and Walls: Fences and walls up to 4 feet in height are permitted in any required street setback. Fences and walls up to 7 feet in height are permitted in required side or rear yards [Section 3.2.6.A.3].

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