Accessory Dwelling Units in Annandale, VA

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Accessory Dwelling Units in Annandale, VA: Enhancing Flexible Living Options

Annandale, a diverse and well-established community in Fairfax County, provides an ideal environment for homeowners seeking to enhance their property’s function and value with an Accessory Living Unit (ALU)—Fairfax County’s term for Accessory Dwelling Units (ADUs).

Thanks to its mix of mid-century homes, quiet subdivisions, and larger-than-average lots in many pockets, Annandale offers unique potential for homeowners to explore secondary living spaces without leaving the neighborhood they love.

ALU Regulations in Annandale (Fairfax County)

Homeowners in Annandale must follow the county-wide ALU guidelines outlined by Fairfax County. These rules help balance neighborhood cohesion with homeowner flexibility.

Regulation Category Rule Summary
Eligibility ALUs are only allowed on single-family detached homes.
Size Limits Interior ALUs: up to 800 sq ft or 40% of the main home’s gross floor area. Detached ALUs: up to 1,200 sq ft on lots ≥2 acres.
Occupancy Max. 2 persons; owner must live on the property.
Parking One extra on-site parking space required in addition to existing requirements.

Detached ALUs are more feasible in sections of Annandale where lot sizes meet the two-acre minimum—typically near Accotink Park, Americana Drive, or southern Woodburn areas.

ALU Permitting Process for Annandale Residents

Permitting is handled by Fairfax County’s PLUS portal and varies by ALU type:

  • Interior ALUs: May qualify for an administrative permit if they meet all design and size requirements.

  • Detached ALUs: Require a special permit, which includes a site plan review, zoning compatibility check, and potentially public hearings.

Be sure to review any subdivision covenants or property easements before applying, especially in older neighborhoods with layered utility or access agreements.

Costs of Adding an ALU in Annandale

Construction costs depend on location, utility access, and design preferences. General ranges include:

Type of ALU Estimated Cost per Sq Ft
Interior Conversion $275–$325
Detached Construction $325–$400

For a 1,200 sq ft detached unit, homeowners should budget between $390,000 and $480,000, excluding permitting and utility extensions.

Why Consider an ALU in Annandale?

Annandale offers both established infrastructure and family-oriented neighborhoods, making it a strong candidate for homeowners seeking more flexibility. Common motivations include:

  • Independent suites for elderly parents or caregivers

  • Private spaces for college students or returning adult children

  • Rental income through long-term tenants in self-contained units

  • Guest lodging for extended family or visitors

With close access to Little River Turnpike, I-495, and Route 236, Annandale is a commuter-friendly location—enhancing the rental appeal of ADUs in this area.

For a comprehensive guide, visit our Fairfax County ADU resource.