Grannio

ADU Rules & Cost in Virginia

A 700 sq ft detached ADU in Virginia typically costs $151,000$247,000 ($216$353/sq ft). Here is what the rules allow.

Local zoning governs — no statewide ADU law

Virginia ADU rules at a glance

This state has no statewide by-right ADU law, so accessory dwelling units are governed entirely by your city or county zoning code. Many cities still allow ADUs — check your local planning department for size, setback and parking rules.

Statewide law
No — local rules
Max detached size
Set locally
Guaranteed minimum
Set locally
Setback
Set locally
Owner-occupancy
Varies locally
Approval time
Set locally

Parking: Set by local ordinance — commonly 1 space per ADU unless near transit.

Estimate your Virginia ADU

Pre-set to Virginia. Adjust the type and size for your project.

Your property

ADU type

Estimated cost in Virginia

$151,000 $247,000

$216$353/sq ft turnkey · midpoint $199,000

$135,300
Construction
$35,800
Design & permits
$27,900
Site work
ADU rules in Virginia are set by your city — here's what to check.
  • iSize set locally. This state leaves ADU size limits to your city — typical caps run 600–1,200 sq ft. Check your local code.
  • iParking. Set by local ordinance — commonly 1 space per ADU unless near transit.
  • iOwner-occupancy varies. Owner-occupancy rules are set locally in this state.
  • Lot has room. A 700 sq ft ADU uses about 12% of your 6,000 sq ft lot — comfortably within typical coverage limits.

Rule basis: Local zoning governs — rules vary by city/county

If you rent it out

$1,050$1,700

est. rent/mo

8.3%

gross yield

13 yrs

payback

~$15,345/yr after a 7% vacancy allowance, before financing & maintenance.

Financed over 20 yrs at 7.5%, the build is about $1,603/mo — vs ~$1,375/mo in estimated rent.

Get your detailed feasibility report →

Estimates are for planning only and are based on regional construction-cost indices and published statewide ADU statutes. Local ordinances, lot conditions and contractor pricing vary — always confirm with your city planning department and a licensed contractor.

Cost by ADU type in Virginia

ADU type600 sq ft$/sq ft
Detached new build$129,500$211,500$216$353
Attached addition$117,500$194,000$196$323
Garage conversion$70,500$129,500$118$216
Junior ADU (JADU)$59,000$106,000$98$176
Prefab / modular$106,000$176,500$176$294

ADU rules by city in Virginia

Estimates are for planning only and are based on regional construction-cost indices and published statewide ADU statutes. Local ordinances, lot conditions and contractor pricing vary — always confirm with your city planning department and a licensed contractor.