Accessory Dwelling Units in Springfield, VA: Suburban Expansion Made Simple

Springfield's suburban layout and generous lot sizes make it well-suited for Accessory Dwelling Units (ADUs)—also known in Fairfax County as Accessory Living Units (ALUs). Whether you're looking to accommodate extended family, create a private rental unit, or simply boost your home’s functionality, Springfield offers an accessible environment for ADU development.

What You Can Build: ADU Regulations in Springfield (Fairfax County)

Springfield falls under Fairfax County’s ALU regulations, which aim to balance neighborhood character with homeowner flexibility.

Regulation Category	Rule Summary
Eligibility	ALUs allowed only on single-family detached homes.
Size Limits	Interior ALUs: ≤800 sq ft or 40% of the main dwelling; Detached: ≤1,200 sq ft if lot ≥2 acres.
Occupancy	Max. 2 persons; owner must reside on the property.
Parking	One additional on-site parking space required.

Detached ALUs are typically viable only in sections of Springfield where lots exceed two acres, such as parts of South Run or leafy residential zones near Accotink Creek.

ALU Permitting Process in Springfield

Permitting is managed centrally by Fairfax County. The process differs depending on whether your ADU is located inside the existing home or in a new standalone structure:

Interior ALUs: Apply via Fairfax County’s PLUS portal for an administrative permit.
Detached ALUs: Require a special permit (Fairfax County), which involves site plan review, neighborhood compatibility checks, and compliance with building codes.

Springfield Tip: While HOA oversight is less common here than in McLean, it’s still wise to verify any local subdivision covenants or easements before starting construction.

Costs to Consider

ADU costs can vary depending on finishes, access, and utility setup. Below are general estimates:

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

Why Add an ADU in Springfield?

Springfield’s location and zoning make it ideal for homeowners looking for functionality without formality. Common use cases include:

Multigenerational living: Private suites for aging parents or college-age children
On-property rental income: Supplement mortgage or retirement income
Guest accommodations: Detached guest homes for visiting family

Its proximity to I-495 and I-95 also makes Springfield attractive for renters who need easy commuter access to D.C., Fort Belvoir, or Tysons.

Explore more in our Fairfax County ADU resource.