ADU Pass
Rosslyn
Also known as Rosslyn-Ballston Corridor (R-B), Gateway Park district, Radnor Heights, Marine Corps War Memorial area, USA Today / Gannett HQ vicinity, Key Bridge area
ADU Pass helps homeowners in Rosslyn — a USPS locale inside Arlington, No County, Virginia — navigate the permit paperwork for building an accessory dwelling unit. This locale covers 1 ZIP code.
Locale-specific ADU details
Site (parcel physics)
Slope:
Soil:
Lot profile:
Geo-hazards:
Recent ADU permit activity
Utility capacity (upgrade likelihood)
Housing stock age:
Electric service drop:
Sewer lateral:
Water pressure:
Gas availability: available — Natural gas mature throughout Radnor Heights.
Locale property values
Radnor Heights bluff bungalows carry Potomac-view premiums on top of Metro proximity; this median reflects only the SFR portion of the locale, not the Rosslyn high-rise core.
Locale overlays (3)
- other
Governs Rosslyn high-rise core; Radnor Heights SFR strip is outside the sector and follows standard Arlington zoning + EHO. - other
Rosslyn is the highest ground in the immediate Potomac area; tall structures historically require FAA obstruction evaluation. ADUs are well below the height threshold but ridge-line parcels may need to confirm 35-ft clearance. - flood-zone
Most of Rosslyn (including Radnor Heights bluff) sits well above the Potomac and is Zone X. Potomac shoreline strip and Theodore Roosevelt Island approach are Zone AE.
Inherited from the city
These sections come from the city page. Click through to the Arlington ADU research for details.
- ADU legality
- legal history
- size range
- permitting process & fees
- permit forms
- contacts
- utilities
- incentives
- viability
- resale value impact
- construction timeline
- pre-approved plans
- financing
- service complexity
Arlington — city ADU rules and incentives
ADU legality: unclear
Virginia leaves ADU regulation to local municipalities under home-rule or Dillon-rule authority. Arlington permits ADUs subject to local conditions per its zoning ordinance.
City cost envelope
$141,025 all-in for a 525 sqft ADU (permit + build). Midpoint scenario.
Permit fee bundle: $1,900.
City viability (selected uses)
County: no attribution (synthetic bucket)
No county
This city sits in the state's "no county" bucket — its ADU rules derive directly from state law and city ordinance without a county intermediary. No county-level sections apply.
Virginia state — ADU law and programs
State ADU law
Virginia has NOT enacted a statewide ADU preemption law. Virginia is a Dillon Rule state — localities possess only those powers expressly granted by the General Assembly — and the statutes granting zoning authority (Va. Code § 15.2-2280 et seq.) leave ADU regulation to local ordinances. ADU permission, setbacks, parking, size, and owner-occupancy rules therefore vary by county, independent city, and town. Virginia is unique in that it has 38 independent cities that function as counties (neither in nor subordinate to the surrounding county), meaning 'the county' for any given Virginia property may be an independent city rather than a true county. Several ADU preemption bills have been introduced in recent General Assembly sessions (2022 through 2025) without enactment; none have advanced past committee as of the Assembly's 2026 regular session adjournment.
State financing programs
Virginia does not operate an ADU-specific statewide loan, grant, or forgivable-loan program. Virginia Housing (formerly the Virginia Housing Development Authority, VHDA — rebranded 2020) administers general first-time-homebuyer, down-payment-assistance (DPA), mortgage-credit-certificate, and rehabilitation products that can be applied to ADU-adjacent purchases or improvements when eligibility criteria are met, but none target ADU construction as a distinct product. The Virginia Department of Housing and Community Development (DHCD) administers federal HOME and CDBG pass-through funds that local jurisdictions can direct toward ADU-adjacent rehab, but there is no state-level ADU-dedicated line item. Federally available products (FHA 203(k), Fannie Mae HomeReady and HomeStyle Renovation, Freddie Mac CHOICERenovation) remain the primary ADU financing path for Virginia homeowners.
State housing programs
Virginia does not run a state-level pre-approved-ADU-plan catalog, statewide impact-fee-waiver statute for ADUs, or streamlined-review mandate. State-level programs that touch ADU-adjacent policy are coordinated primarily through the Department of Housing and Community Development (DHCD) and Virginia Housing, and act by funding or assisting local jurisdictions rather than by preemption. Local ADU activity — Arlington County's Accessory Dwellings program (detached ADUs permitted since 2008, liberalized 2020), Alexandria's accessory-dwelling ordinance, Fairfax County's accessory-living-unit program, and Charlottesville's 2021 zoning-code changes — is authorized under the localities' Va. Code § 15.2-2280 zoning authority, not by state mandate.
- DHCD Community Development Block Grant (CDBG) Program — Federal CDBG funds administered by DHCD to eligible non-entitlement Virginia localities for community-revitalization, housing-rehab, and infrastructure projects. Not ADU-specific. Participating localities can direct CDBG funds toward housing-rehab projects where local policy supports ADUs.
- DHCD HOME Investment Partnerships Program — Federal HOME funds administered by DHCD to Virginia participating jurisdictions and non-profits for affordable-housing acquisition, rehab, and new construction. Not ADU-specific; can be directed to ADU-adjacent rehab at local discretion.
- Virginia Housing Commission — Permanent advisory commission of the General Assembly that studies housing-policy questions and recommends legislation. Has periodically studied ADU preemption and missing-middle housing without recommending statewide enactment as of 2026-04-21.
- Local ADU ordinances under Va. Code § 15.2-2280 authority — Not a state program — listed here because Virginia ADU policy is executed entirely at the locality level under the § 15.2-2280 zoning grant. A homeowner seeking to build an ADU consults the zoning ordinance of the specific county, city, or town where the parcel is located.
Federal (United States) — ADU-relevant rules and programs
Federal ADU law
The United States has no federal statute that directly regulates accessory dwelling unit entitlement or design. Land-use authority over ADUs resides with states and local governments under the traditional police power. Federal engagement is limited to financing (Fannie/Freddie/FHA/VA/USDA), flood insurance (FEMA/NFIP), and discretionary housing programs (HUD), which are recorded in sibling sections of this file.
Federal financing programs
Federal housing-finance agencies and GSEs set nationwide underwriting rules that govern whether an ADU can be financed, appraised, and counted toward mortgage qualifying income. The relevant actors are Fannie Mae, Freddie Mac, FHA (HUD), VA, and USDA Rural Development.
Federal tax credits
There is no ADU-specific federal tax credit. ADUs may incidentally qualify for existing federal energy-efficiency and clean-energy tax credits when the ADU construction includes qualifying measures.
Federal housing programs
HUD administers several discretionary programs that can fund ADU-related activity at the grantee's election, but none is an ADU-specific program.
ZIP Code
- 22219
Post Office
- 1550 Wilson Blvd Ste 100, 22209