ADU Pass
The Plains
ADU Pass helps homeowners in The Plains, Fauquier 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
Three-step pathway: (1) Town zoning permit, (2) Architectural Review Board Certificate of Appropriateness if any exterior work visible from public way (most of town is in historic district), (3) Fauquier County building permit. The Plains is exceptionally small (~120 households); the Town Clerk/Treasurer handles intake and the ARB meets monthly. HB 1832 effective 2026-07-01 will preempt special-use-permit and consanguinity barriers but NOT historic-district design review.
Cost scenarios
| Scenario | Sq ft | Permit | Build | Total |
|---|---|---|---|---|
| minimum | 350 | $1,380 | $119,000 | $120,380 |
| 600 | 600 | $1,750 | $234,000 | $235,750 |
| maximum | 800 | $1,850 | $312,000 | $313,850 |
Fee breakdown (as of 2026-04)
Permitting process
- Town Hall pre-application meeting (~5d)
Visit The Plains Town Hall (6451 Main Street) or call 540-364-4945 to discuss the project with the Town Clerk/Treasurer. Confirm whether the parcel is within the ARB historic-district overlay (most are), zoning district, accessory-use permissibility, lot-coverage and setback rules. - Town zoning permit application (~1d)
Submit the Town's Zoning and Sign Permit Application with $50 fee. Include site plan, elevations, materials list. Required BEFORE any County building-permit submission. - Architectural Review Board Certificate of Appropriateness (~45d)
If any exterior work is visible from a public street (true for nearly all detached ADUs in Town), the ARB application is filed in parallel. ARB meets monthly; design review covers materials, fenestration, scale, siting, landscaping. No fee. May require revisions and a return visit. - Town zoning permit issuance (~7d)
Town Clerk/Treasurer issues approved Zoning Permit after ARB Certificate of Appropriateness (if applicable) is signed. - Fauquier County building permit application (~1d)
Submit building permit application to Fauquier County Department of Community Development with the approved Town zoning permit and ARB COA attached. Trade permits (electrical/plumbing/mechanical) filed concurrently by Virginia DPOR-licensed contractors. - Fauquier County plan review (~30d)
County reviews stamped plans against 2021 Virginia USBC. Typical 4-5 week review; expedited review unavailable. - Construction inspections
Footing/foundation, framing, MEP rough-in, insulation, drywall, final inspections by Fauquier County inspector. Inspector drives from Warrenton; typical 2-3 day response. - Certificate of Occupancy and notifications (~7d)
Final inspection by County triggers CO. Town Treasurer notified for Town tax, water/sewer billing; Fauquier County Commissioner of the Revenue notified for supplemental real-estate assessment.
Viability (permitted uses)
- Long-term rental: yes (Va. Code Section 55.1-1200 (Virginia Residential Landlord and Tenant Act)) Long-term rental of an ADU is permitted; landlord-tenant law applies.
- Short-term rental: with-restrictions (Town Hall + Fauquier County STR Administrative Permit Section 5-303) The Plains has not adopted a separate STR ordinance; verify current Town policy with Town Clerk. The Plains is in horse-country tourism corridor (Great Meadow steeplechase, hunt events) which generates STR demand. Outside Town limits, Fauquier County STR Administrative Permit applies.
- Office rental: with-restrictions Detached office rental requires home-occupation permit; Town allows home occupations in residential districts with limited customer traffic.
- Home office: yes Home occupation permitted with restrictions on signage (additional ARB review for any new signs visible from public way).
- Studio / workshop: yes Personal studio (artist, music, woodworking) is a permitted accessory use.
- Agriculture: with-restrictions Town residential districts allow garden plots; Town surrounded by horse farms but in-town livestock is restricted.
- Relative support: yes Family/multigenerational accessory dwelling permitted under accessory-use provisions.
Incentives
- Virginia Historic Rehabilitation Tax Credit (state, 25%) — 25% of qualified rehab expenditures (Applies to contributing structures within The Plains Historic District (NRHP-listed 1985); minimum $25K rehab spend on owner-occupied; certified by DHR)
- Federal Historic Rehabilitation Tax Credit (20%) — 20% of qualified rehab expenditures (income-producing only) (Income-producing rehabilitation of NRHP contributing structures; not available for owner-occupied principal residences)
Contacts
Staff: Nancy E. Brady (Town Clerk / Treasurer), Architectural Review Board (Historic-district design review (monthly meetings)), Fauquier County Community Development (Building Permits and Inspections)
Utilities
- Water: Town of The Plains Public Water (within town limits) · 35d connect · $5,500
- Sewer: Town of The Plains Wastewater (within town limits); private septic outside · 50d connect · $8,500
- Electric: Rappahannock Electric Cooperative (REC) covers most of Fauquier; The Plains served by REC · 30d connect · $2,400
- Gas: No natural-gas distribution; bottled propane (AmeriGas, Suburban Propane) is the norm · 14d connect · $1,900
Property values & taxes
Market rent by ADU size
| Sq ft | Rent |
|---|---|
| 350 | $1,175/mo |
| 600 | $1,700/mo |
| 800 | $2,025/mo |
Construction timeline
Realistic total: best 9mo · typical 14mo · worst 22mo
Hunt-country GC pool is shallow but serves a wealthy clientele; ARB-experienced GCs are typically Warrenton- or Middleburg-based and book months ahead. Historic-materials sourcing (slate, salvage millwork) adds 4-6 weeks.
Modular pathway Virginia DHCD Industrialized Building Unit (13 VAC 5-91) · inspectors are rare with modular
I-66 / US 17 access good; in-town historic-district narrow streets and ARB compatibility findings effectively rule out boxy modular forms.
Financing
State ADU loans:
- Virginia Housing first-time-buyer / DPA programs (Virginia Housing)
Insurance impact
Hunt-country insurance market is small but specialized; ADU on a $685K-median-value property carries a higher absolute premium delta than typical rural Virginia.
HOA prevalence & preemption
The Plains is mostly older platted Town lots without HOAs. Surrounding hunt-country parcels are large fee-simple farms. Virginia has no HOA-ADU preemption.
Regulatory overlays (2)
- historic-district — The Plains Historic District (NRHP-listed 1985) + Town ARB overlay covers approximately 80%+ of developed Town area · +45d · +12% cost
Town ARB review required for any exterior change visible from public street. Materials, fenestration, scale, and siting all reviewed for compatibility with district character. (map) - flood-zone — Goose Creek tributaries traverse Town fringes; FEMA SFHA Zone AE on small portions · +14d · +6% cost
Flood zone affects only a minority of Town parcels; finished-floor elevation requirements where applicable. (map)
Technical envelope (climate & building code)
Climate & energy code
Building code
Amendments:
- Virginia USBC state amendments (13 VAC 5-63) — Includes the residential fire-sprinkler R313 deletion.
Contractor market (aggregate)
Legal history (timeline)
Current ordinance: Town of The Plains Zoning Ordinance + ARB Ordinance, adopted 1995-01-01, last amended 2017-01-01
- 1910-01-01 — Town of The Plains incorporated by Virginia General Assembly (state-charter)
Original incorporation; the Town's small footprint and historic character were established at this time.
Effect: Established the Town's separate municipal authority including zoning. - 1985-01-01 — The Plains Historic District added to National Register of Historic Places (national-register)
The Town's central commercial core and adjacent residential blocks designated NRHP historic district.
Effect: Triggered Town adoption of an Architectural Review Board ordinance to protect the district's appearance. - 1995-01-01 — Town of The Plains Architectural Review Board ordinance (city-ordinance)
Town adopted local design-review ordinance under Va. Code Section 15.2-2306.
Effect: Required Certificate of Appropriateness for any exterior change visible from a public street within the historic-district overlay; covers approximately 80%+ of developed Town area. - 2017-01-01 — Town of The Plains Comprehensive Plan update (city-ordinance)
Most recent comprehensive-plan refresh; reviewed in 2017.
Effect: Reaffirmed the Town's small-scale residential character; no specific ADU language adopted. - 2026-07-01 — HB 1832 / HB 2533 - Statewide ADU by-right preemption (pending effective date) (state-law)
Requires all Virginia localities to permit ADUs as a by-right accessory use in single-family districts.
Effect: Applies to The Plains as a chartered locality. Will void special-use-permit barriers but does not preempt historic-district ARB design-review requirements.
Fauquier County — county ADU rules and overlays
County ADU ordinance
Fauquier County permits one accessory dwelling unit per lot in residential and rural-ag districts subject to size, occupancy, and placement standards. The county's definition is strict: an ADU may be attached to, inside of, or detached from the principal dwelling, but no more than one ADU is allowed per lot and it may not be occupied by more than three persons or contain more than two bedrooms. Base size cap is 800 sqft. Lots of at least five acres in the RA (Rural Agricultural) or RC (Rural Conservation) districts may go up to 1,000 sqft, and where a legally existing pre-2013 dwelling in RA/RC on a five-plus-acre lot is being converted to the ADU the cap rises to 1,400 sqft or the existing unit's square footage (whichever is less). Detached ADUs require a side or rear external entrance. Fauquier's ordinance is unusually preservation-oriented: the 800-sqft base cap and the three-person occupancy limit are tighter than most Northern Virginia peers, reflecting the county's horse-country / agricultural-preservation zoning culture.
County regulatory overlays
Fauquier County administers four overlay regimes that bear materially on ADU projects: (1) a Floodplain Overlay District under Zoning Ordinance Section 4-400 tied to FEMA Special Flood Hazard Areas; (2) locally-adopted Historic Overlay Districts reviewed by the county's Architectural Review Board (distinct from the Commonwealth's Virginia Landmarks Register and the National Register); (3) an extensive network of conservation easements held by the Virginia Outdoors Foundation (VOF), Piedmont Environmental Council (PEC), and the Northern Virginia Conservation Trust (NVCT) on RA and RC parcels, which typically pre-empt ADU rights even where zoning would otherwise permit; and (4) the county's Service District framework (Bealeton, Catlett, Marshall, Midland, New Baltimore, Opal, Remington, Warrenton) inside which development standards are tuned for higher density and public utility connection. Fauquier has no coastal-commission jurisdiction, no CalFire-equivalent WUI regime (Virginia has no statewide wildland-urban-interface overlay), and no seismic-retrofit overlay.
- Floodplain Overlay District
- Fauquier County Historic Overlay Districts
- Conservation Easement Overlay (VOF, PEC, NVCT-held easements)
- Service District framework (Bealeton, Catlett, Marshall, Midland, New Baltimore, Opal, Remington, Warrenton)
County permitting (unincorporated parcels)
Fauquier County's Department of Community Development issues ADU building permits for every parcel in the county except those inside the Town of Warrenton (which operates its own zoning and building department). Unincorporated CDPs (Bealeton, Catlett, Marshall, Midland, New Baltimore, Opal, Remington outside the town limits, and the eight other service districts) all route through the county's building division. A typical ADU permit bundle includes: (1) a Zoning Permit confirming use and dimensional compliance, (2) a Building Permit with stamped plans, (3) Electrical, Plumbing, and Mechanical trade permits, (4) a Virginia Department of Health (VDH) - Fauquier Environmental Health construction permit for well and/or septic on parcels not served by public water or sewer, (5) a Floodplain Development Permit if any portion of the parcel is within the Floodplain Overlay District (Section 4-400), and (6) a Historic District Certificate of Appropriateness if the parcel is in a designated Fauquier Historic Overlay District.
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
- 20198
Post Office
- 4314 Fauquier Ave, 20198