ADU Pass
Warrenton
No County portion
Also in: Fauquier County
ADU Pass helps homeowners in Warrenton, No County, Virginia navigate the permit paperwork for building an accessory dwelling unit. This area covers 1 ZIP code.
Map
ADU details
ADU legality: allowed-with-restrictions
Warrenton, the Fauquier County seat, permits ADUs under its town zoning ordinance with a formal accessory-dwelling definition (Sept 2024 update). Old Town historic-district CofA review applies for exterior changes in the downtown core. Fauquier hunt-country character and the Warrenton Hunt establish a design-and-character expectation that informs ADU detailing. SB531 (July 2027) further simplifies by-right permitting.
Cost scenarios
| Scenario | Sq ft | Permit | Build | Total |
|---|---|---|---|---|
| minimum | 300 | $1,700 | $114,000 | $115,700 |
| 600 | 600 | $2,000 | $246,000 | $248,000 |
| midpoint | 600 | $2,000 | $246,000 | $248,000 |
| maximum | 900 | $2,300 | $387,000 | $389,300 |
Fee breakdown (as of 2026-05)
Permitting process
Viability (permitted uses)
- Long-term rental: yes Long-term rental permitted on Warrenton SFR parcels with ADU. NoVA / DC commute corridor (US-29) and Fauquier hospital workforce drive sustained year-round rental demand.
- Short-term rental: with-restrictions Warrenton STR Administrative Permit applies per Zoning Ordinance Section 5-303. Strong seasonal demand — Fauquier hunt-country events, Foxfield Races, Virginia Gold Cup, and Old Town tourism.
- Office rental: no ADU must remain a dwelling unit.
- Home office: yes Home occupation permitted.
- Studio / workshop: yes Personal studio / workshop use permitted; common on Warrenton equestrian parcels.
- Agriculture: with-restrictions Limited in town residential districts; common on outlying Fauquier rural parcels.
- Relative support: yes Family-occupancy ADU permitted; common multi-generational pattern.
Incentives
Contacts
Utilities
- Water: Town of Warrenton Department of Public Utilities (Lake Brittle / Smith Lake sources) · 28d connect · $5,500
- Sewer: Town of Warrenton Department of Public Utilities (Warrenton Wastewater Treatment Facility) · 30d connect · $7,200
- Electric: Dominion Energy Virginia (most of Warrenton); some parcels on Rappahannock Electric Cooperative · 28d connect · $2,000
- Gas: Columbia Gas of Virginia (parts of Warrenton); propane elsewhere · 28d connect · $1,700
Property values & taxes
Construction timeline
Realistic total: best 7mo · typical 10mo · worst 15mo
Modular pathway inspectors are occasional with modular
US-29, US-211, and US-17 handle modular delivery. Rural Fauquier roads generally accommodate standard module widths.
Financing
Insurance impact
HOA prevalence & preemption
Mix of older Old Town parcels (no HOA, CofA review applies) and newer subdivisions on the south/east edges of town (Warrenton Lakes, Brookside, etc.) with active HOAs.
Regulatory overlays (2)
- historic-district
Locally-designated Old Town Historic District with NRHP listing; Architectural Review Board CofA review required for visible exterior changes. - flood-zone
Limited FEMA AE flood-zone exposure along Cedar Run and adjacent drainages. Most Warrenton parcels are outside SFHA.
Technical envelope (climate & building code)
Climate & energy code
Building code
Amendments:
- Amendment
Contractor market (aggregate)
Legal history (timeline)
Current ordinance: Town of Warrenton Zoning Ordinance (September 2024 update), adopted 1998-01-01, last amended 2024-09-01
- 1998-01-01 — Town of Warrenton Comprehensive Zoning Ordinance — modern framework origin (city-ordinance)
Warrenton's current Zoning Ordinance framework traces to the late-1990s comprehensive update establishing Article 3 zoning districts and use standards.
Effect: Established Old Town, R-6, R-10, R-15, R-25, and other district designations still in use. - 2024-09-01 — Town of Warrenton Zoning Ordinance — September 2024 amendment incorporating ADU definition (city-ordinance)
Town Council adopted the September 2024 ZO update which includes the explicit Accessory Dwelling Unit definition and use-specific standards in Article 5.
Effect: Current operating ADU framework for Warrenton. - 2026-04-14 — Virginia SB531 signed — statewide by-right ADU mandate (state-law)
Effective July 1, 2027: by-right ADU on SFR lots; $500 fee cap.
Effect: Warrenton's pre-Jan 2026 ZO update qualifies for grandfathering; $500 fee cap takes effect 2027-07-01.
Known issues (2)
- other — Old Town CofA review adds 30-60 days to projects with visible exterior changes. Plan for the Architectural Review Board cycle when budgeting timeline.
- other — Town water and sewer capacity is a recurring planning topic given Warrenton's growth; ADU connections counted against town allocation. Confirm capacity with Public Utilities during pre-application.
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
- 20188
Post Office
- 53 Main St, 20186