How Alexandria Handles Accessory Structures: A Practical Guide
Alexandria maintains 116 local ordinances across all categories, and 2 of those deal specifically with accessory structures. Here is a breakdown of what the city actually requires, what is prohibited, and where Alexandria falls on the strict-to-permissive spectrum compared to other cities.
ADU Rules
Alexandria's Zoning Ordinance lets homeowners add one accessory dwelling unit to a single-unit, two-unit, or townhouse property under Section 7-203. A detached ADU tops out at one-third of the principal home's first-floor area or 350 to 500 square feet, whichever is greater, capped at 20 feet in height, with no off-street parking required.
Key details: Eligible lots: Single-unit, two-unit, or townhouse dwellings only. ADUs per lot: One accessory dwelling per recorded lot. Detached ADU max size: 1/3 of home's 1st floor, or 350-500 sq ft. Max height: Lesser of home's height or 20 feet. Min side/rear setback: 1 foot, more for taller or windowed walls.
An accessory dwelling built or used outside these limits is a use, height, or coverage violation of the zoning ordinance under Section 11-207(A), punishable as a class five civil violation: $200 for a first offense and $500 for each later violation of the same requirement, up to $5,000 total for a repeated series arising from the same facts. The director can also issue a written notice under Section 11-204 ordering the illegal structure or use corrected within ten days before pursuing court action to restrain or abate it.
Shed & Carport Rules
Alexandria lets homeowners put a shed in the side or rear yard without giving up required yard space, but caps its size. Section 7-202(C)(2) allows sheds up to 100 square feet and 10 feet tall on single- and two-unit lots outside a historic district, shrinking to 65 square feet and 8 feet tall inside the Old and Historic Alexandria or Parker-Gray districts.
Key details: Standard lot shed limit: 100 sq ft, 10 ft tall (§ 7-202(C)(2)(a)). Historic district shed limit: 65 sq ft, 8 ft tall (§ 7-202(C)(2)(b)). Allowed location: Side or rear yard only, never front yard. Measurement rule: Floor area capped in the aggregate, per lot. Permit still required: Building permit from Dept. of Code Administration.
A shed that exceeds the aggregate 100-square-foot, or 65-square-foot in the historic districts, floor area or height cap loses its exemption from yard setback requirements and becomes an ordinary accessory structure that must meet the zone's standard setbacks, a violation if built without meeting them. Alexandria's Department of Code Administration and Planning & Zoning can require the oversized shed relocated, reduced, or removed, and enforcement follows the ordinance's general zoning violation process.
The Bottom Line
Alexandria's accessory structures rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Alexandria is broadly strict or permissive.
Keep in mind that Alexandria can amend these rules at any council meeting. For the most current version of any rule mentioned here, check the specific ordinance page, where we track updates as they happen.