Virginia ADU Laws & Permit Guide (2026)
Virginia passed legislation in 2023 requiring localities to adopt regulations permitting ADUs in single-family zones. Northern Virginia (Fairfax, Arlington, Alexandria) has the most active ADU markets in the state.
Virginia ADU At a Glance
Permit Timeline
60–120 days
Average Build Cost
$110,000 – $280,000
Maximum Size
Varies by locality
Owner-Occupancy Required
Not required under 2023 state law
Impact Fees
Varies by locality
Setbacks
Varies; Northern Virginia typically 5 ft rear and side
Recent Law Changes in Virginia
Required all Virginia localities to adopt ordinances permitting accessory dwelling units in single-family residential zones. Prohibits owner-occupancy requirements and limits local restrictions on ADU size and design.
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Browse Virginia Contractors →Frequently Asked Questions — ADUs in Virginia
Are ADUs legal throughout Virginia?
Yes. HB 2045/SB 1416 (2023) requires all Virginia localities to allow ADUs in single-family residential zones. Northern Virginia jurisdictions including Arlington, Alexandria, and Fairfax County have well-established ADU programs.
How much does it cost to build an ADU in Virginia?
Virginia ADU costs typically range from $110,000 to $280,000 for a detached unit. Northern Virginia, due to its proximity to DC and high labor costs, tends to run on the higher end. Southwestern Virginia markets are generally less expensive.
How long does ADU permitting take in Virginia?
Virginia ADU permit timelines range from 60–120 days. Arlington County and Alexandria have streamlined processes. Fairfax County, due to volume, may take slightly longer. Rural localities vary widely.
Do I need to live on my property to build an ADU in Virginia?
No. Virginia's 2023 ADU law explicitly prohibits localities from imposing owner-occupancy requirements on ADU properties.
What is the maximum size for an ADU in Northern Virginia?
Maximum ADU size varies by locality. Arlington County allows detached ADUs up to the lesser of 1,000 sq ft or 35% of the primary home's floor area. Fairfax County has different standards. Check with your local planning department for the specific rules that apply to your property.
Sources
- VA Department of Housing — ADU Resources ↗
- Arlington County — ADU Information ↗
- Fairfax County — Accessory Living Units ↗
Disclaimer: The information on this page is provided for general informational purposes only and does not constitute legal, financial, or construction advice. ADU regulations change frequently — always verify current rules with your local planning department and consult a licensed professional before making decisions. ADUHomeResource.com is not liable for any errors, omissions, or outcomes resulting from use of this information.