Setbacks & Height Limits in Arlington County

This guide explains the basic setback and height rules that apply to residential construction in Arlington County, Virginia. Arlington is an urban county (not an incorporated city) and is governed by the Arlington County Zoning Ordinance, administered by the Department of Community Planning, Housing & Development (CPHD). These rules depend on your exact zoning district, overlay zones, and lot geometry, so always confirm with CPHD before finalizing plans.

What Are Setbacks?

A setback is the minimum required distance between a building and a lot line. Setbacks are measured from the property line to the nearest point of the principal building wall. Eaves, bay windows, chimneys, stoops, and accessory structures have their own allowances in the Arlington County Zoning Ordinance.

The Zoning Ordinance specifies front, side, and rear setbacks separately for each zoning district. Corner lots have two "front" setbacks (one per street frontage) with one interior side and one rear.

Typical Residential Setbacks (R-5 through R-20)

Arlington County's single-family residential districts are scaled by minimum lot size — the larger the minimum lot, the larger the required setbacks. Typical by-right values for the main single-family districts are approximately:

These are typical by-right figures. Your specific lot may have different requirements due to overlays, historic district designation, reduced-width lots, or the EHO program (see below). Multifamily (RA), commercial (C-1, C-2, C-O), and mixed-use corridor districts have entirely separate setback schedules.

Height Limits

By-right maximum building height in Arlington County's R-5 through R-20 single-family districts is 35 feet, measured from average existing grade to the midpoint of a pitched roof (or to the top of a flat roof). Accessory structures such as detached garages and ADUs are limited to a lower cap — typically 25 feet or less.

Height rules get more complicated in:

• Rosslyn-Ballston Corridor and Jefferson Davis Corridor — C-O and mixed-use districts allow significantly greater height, with Rosslyn permitting building heights up to 300 ft in specific sites
• Historic districts — height and massing may be constrained by the Historical Affairs and Landmark Review Board (HALRB)
• EHO (Missing Middle) projects — still capped at 35 ft, but unit type is expanded
• Airport overlays — proximity to Reagan National Airport can impose FAA-driven height limits

Lot Coverage

Beyond setbacks and height, lot coverage shapes how much of the parcel the building can occupy. Arlington County's single-family R-districts typically cap main building lot coverage at around 30% to 56% of lot area, depending on the district and lot size, with sliding scales for smaller lots. Accessory buildings count separately and are also capped. Arlington does not generally apply a numeric FAR (Floor Area Ratio) in its standard single-family districts — the building envelope is controlled by setbacks, height, and coverage.

Missing Middle / EHO (2023)

In March 2023, the Arlington County Board adopted the Expanded Housing Options (EHO) amendments — commonly called the "Missing Middle" reform. EHO allows up to 6 dwelling units on lots in the R-5, R-6, R-8, R-10, R-15, and R-20 single-family residential districts, subject to:

• An annual county-wide permit cap (initially 58 units/year during the first phase)
• The same base district setbacks, height limit (35 ft), and lot coverage as a conventional single-family house
• Design standards for building form, parking, and tree canopy
• By-right administrative approval (no public hearing) once EHO standards are met

EHO does not relax the building envelope — it expands the permitted use inside that envelope from one detached dwelling to small-scale multi-unit housing (duplexes, triplexes, fourplexes, and up to six-unit buildings). A Virginia circuit court ruling in 2024 vacated the original EHO ordinance; Arlington County has continued to defend and refine the program. Confirm the current EHO status with CPHD before relying on it for a project.

Common Exceptions and Encroachments

Most zoning codes allow certain features to project into required setbacks. Arlington County typically permits:

• Eaves and gutters (limited projection, commonly up to 2 ft)
• Chimneys (limited projection)
• Uncovered porches, stoops, and steps
• Air conditioning condensers (subject to sound and side-yard rules)
• Bay windows (limited projection and width)

Fences, retaining walls, detached accessory structures, and ADUs have separate rules in the Zoning Ordinance.

State ADU Overrides

Virginia has no enacted statewide ADU preemption: SB 304 of 2024 would have required ADUs by-right but was deferred to the Virginia Housing Commission and not enacted. Va. Code § 15.2-2292.1 governs only temporary family health-care structures (≤300 sq ft caregiver units), not general ADUs.

How to Look Up Your Specific Requirements

1. Find your zoning district — use the Arlington County online zoning map (CPHD)
2. Read the district regulations — the Arlington County Zoning Ordinance lists setbacks, height, and coverage for each R-district
3. Check for overlays — historic districts, corridor overlays, and airport zones can modify base rules
4. Check EHO eligibility — if you are considering Missing Middle housing, verify current EHO cap status and design standards
5. Ask CPHD — call (703) 228-3525 for pre-application zoning guidance

Variances

If your project cannot meet the strict letter of the Arlington County Zoning Ordinance, you may apply for a variance from the Board of Zoning Appeals (BZA) — a formal request to deviate based on hardship specific to your lot. Variances are discretionary and require a public hearing. See the Variance Application Guide for the general process.

Official Sources

See the sources linked in the frontmatter for the Arlington County Zoning Ordinance, CPHD, and the EHO program page. This guide is informational and is not a substitute for direct confirmation from CPHD planning staff.

Disclaimer: This guide provides general information about zoning in Arlington County and should not be relied upon as legal advice. Zoning codes are subject to change, and the EHO/Missing Middle program in particular has been the subject of ongoing litigation. Always verify current regulations with Arlington County CPHD before making development decisions.