City of Alexandria ADU rules — what you can build and when.
One of Virginia's earliest ADU adopters — administratively permitted since 2021.
Verify locally — rules are changing ahead of July 1, 2027. This page reflects our working understanding at publication. Always confirm with the City of Alexandria zoning department before you design or file. We handle that verification as part of every Readiness Assessment.
Alexandria in one screen.
- ADUs allowed by-right (administrative permit) since January 2021
- Staff review typically ~10 business days after a complete application
- BAR Certificate of Appropriateness required in historic districts
- Public water and sewer city-wide — no septic constraint
Reading between the lines.
Alexandria was one of the first Virginia jurisdictions to legalize accessory dwellings city-wide. The January 2021 ordinance made ADUs an accessory use to single-unit, two-unit and townhouse dwellings, reviewed administratively rather than through a public hearing.
The practical constraints in Alexandria are rarely about whether you can build — they're about the lot. Small in-town parcels, mature tree canopy, alley access and lot coverage limits do most of the shaping. In the Old and Historic Alexandria and Parker-Gray districts, a Board of Architectural Review Certificate of Appropriateness is required for exterior work, which adds time and design discipline.
Because §7-203 has been amended since adoption, we always re-confirm the current size cap and occupancy language with Planning & Zoning at the start of a project rather than working from a published summary.
Alexandria answers.
Are ADUs legal in Alexandria, VA?
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Yes. Alexandria has permitted accessory dwelling units by-right under Zoning Ordinance §7-203 since January 2021, through an administrative ADU permit rather than a public hearing.
How long does an Alexandria ADU permit take?
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Planning & Zoning targets roughly 10 business days of staff review after a complete application. Building permits, and a BAR Certificate of Appropriateness in historic districts, are separate and add time.
How big can an ADU be in Alexandria?
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The ordinance ties ADU floor area to the principal dwelling. Because §7-203 has been amended since adoption, confirm the current numeric cap with Alexandria Planning & Zoning before designing.
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