ADU Pass
Williamsville
ADU Pass helps homeowners in Williamsville, Highland 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
Williamsville is unincorporated and governed entirely by Highland County zoning. A CUP is the typical pathway for an independent second dwelling. Site-specific constraints — bedrock substrate for wells, septic perc, river corridor flood exposure, steep slopes — usually dominate the project economics over the regulatory layer.
Cost scenarios
| Scenario | Sq ft | Permit | Build | Total |
|---|---|---|---|---|
| minimum | 200 | $2,200 | $54,000 | $56,200 |
| 600 | 600 | $2,200 | $162,000 | $164,200 |
| midpoint | 600 | $2,200 | $162,000 | $164,200 |
| maximum | 1,000 | $2,400 | $270,000 | $272,400 |
Fee breakdown (as of 2026-04)
Permitting process
Viability (permitted uses)
- Long-term rental: yes Long-term rental of an ADU is permitted; Virginia Residential Landlord and Tenant Act (Va. Code Section 55.1-1200 et seq.) applies.
- Short-term rental: with-restrictions Highland County treats short-term tourist rentals as a separately classified use; transient-occupancy tax under Va. Code Section 58.1-3819 et seq. applies. STR demand peaks during the Highland Maple Festival (March) and the fall foliage / hunting seasons.
- Office rental: with-restrictions Detached office rental requires home-occupation review or different district classification.
- Home office: yes Home occupation is permitted with restrictions on signage, traffic, and on-site staff.
- Studio / workshop: yes Personal artist or craft studio is a permitted accessory use.
- Agriculture: yes Agricultural uses are by-right in the Agricultural district; livestock and maple-syrup operations are common in Highland County.
- Relative support: yes Family-occupancy ADU is the most permissive accessory-dwelling pathway; CUP conditions routinely codify familial-relationship limitations.
Incentives
Contacts
Staff: Joshua Simmons (Building Official, Zoning Administrator, and Floodplain Administrator) jsimmons@highlandcova.org
Utilities
- Water: Private well (essentially every Williamsville parcel) · 75d connect · $11,000
- Sewer: Private septic via VDH Central Shenandoah Health District · 75d connect · $14,000
- Electric: BARC Electric Cooperative · 25d connect · $2,000
- Gas: Propane (no natural-gas main) · 14d connect · $1,500
Property values & taxes
Construction timeline
Realistic total: best 10mo · typical 13mo · worst 18mo
Modular pathway inspectors are occasional with modular
Financing
State ADU loans:
Insurance impact
HOA prevalence & preemption
Virginia has no HOA-ADU preemption (Va. Code Title 55.1). HOA prevalence in Williamsville is very low; conservation easements (Virginia Outdoors Foundation, Valley Conservation Council) and forestal-district designations are the more common encumbrances.
Regulatory overlays (2)
- flood-zone
FEMA Special Flood Hazard Area mapping along the Bullpasture and Cowpasture rivers. Floodplain Development Permit required when any portion of the parcel is in the SFHA; finished floor must clear Base Flood Elevation plus Virginia freeboard. (map) - other
Surrounding land is largely federal National Forest; private inholdings are limited and rights-of-way may apply. (map)
Technical envelope (climate & building code)
Climate & energy code
Building code
Amendments:
- Amendment
Contractor market (aggregate)
Legal history (timeline)
Current ordinance: Highland County Zoning Ordinance, adopted ongoing — periodically amended, last amended Confirm with Highland County Department of Building and Zoning at 540-468-2323.
- 1979-01-01 — Va. Code Section 15.2-2280 zoning authority codified (Dillon Rule baseline) (state-statute)
Virginia delegated zoning authority to counties, cities, and towns without an ADU-specific preemption.
Effect: Each Virginia locality regulates ADUs through its own zoning ordinance; ADUs are not automatically permitted statewide.
Known issues (2)
- other — Begin with a VDH-authorized OSE evaluation before committing to an ADU pro forma. AOSS designs add $15-25K and 60-180 days to timeline.
- staffing-shortage — Direct phone contact with the Building Official is often faster than email; budget 90-180 days for CUP approval before building-permit review.
Highland County — county ADU rules and overlays
County ADU ordinance
Highland County does NOT maintain a standalone accessory-dwelling-unit ordinance with codified ADU-specific size caps, setbacks, or owner-occupancy provisions. ADUs in the county are regulated through the general zoning ordinance's treatment of 'accessory use,' 'accessory structure,' and the per-district use schedules administered by Building and Zoning. In the Agricultural and Rural Residential districts that cover the great majority of county acreage, one principal dwelling per lot is permitted by right with customary accessory structures; a second independent dwelling unit with full kitchen facilities typically requires a Conditional Use Permit (CUP) from the Board of Supervisors after Planning Commission recommendation. A 'family-member' or 'tenant dwelling / farm labor dwelling' allowance is generally recognized in the agricultural district subject to minimum lot area. A no-kitchen 'guest house' accessory structure is generally permitted as a by-right accessory use subject to setbacks, height, and lot-coverage limits. Applicants should confirm current ordinance text with Joshua Simmons, Building Official and Zoning Administrator, at 540-468-2323 before committing to a project pro forma — the ordinance is updated periodically and administrative interpretation is load-bearing.
County regulatory overlays
Highland County administers a Floodplain Overlay tied to FEMA Special Flood Hazard Areas along the Jackson, Bullpasture, Cowpasture, and South Branch Potomac headwater systems and their tributaries. The Building Official serves as Floodplain Administrator. Highland County is NOT a Tidewater locality and is therefore NOT subject to the Chesapeake Bay Preservation Act (Va. Code § 62.1-44.15:67 et seq.) — the headwater drainages in Highland flow into the James and Potomac systems, but Highland sits west of the CBPA jurisdictional boundary. Highland County has NO designated coastal-commission analog (none exists in Virginia), NO statewide WUI regulatory overlay (Virginia has no CalFire-style WUI program), and NO seismic-retrofit overlay. There are no FAA Part 150 commercial-airport noise zones reaching the county. The Town of Monterey applies the same county zoning framework with town-level review for the historic core.
County permitting (unincorporated parcels)
Highland County's Department of Building and Zoning, headed by Building Official and Zoning Administrator Joshua Simmons (540-468-2323, jsimmons@highlandcova.org), handles the full local-permitting stack: zoning permits, Conditional Use Permits, site plan review, land-disturbance and erosion-and-sediment-control permits, building permits, trade permit coordination, floodplain development permits, and E-911 addressing. A typical ADU-like permit bundle (where a second dwelling is permitted) includes: (1) pre-application zoning inquiry, (2) Conditional Use Permit from the Board of Supervisors with Planning Commission recommendation (unless the parcel qualifies for an agricultural tenant or farm-labor dwelling allowance, or the project is a no-kitchen 'guest house'), (3) zoning permit confirming use compliance and setbacks, (4) building permit with stamped residential plans, (5) electrical, plumbing, and mechanical trade permits, (6) Virginia Department of Health (VDH) Central Shenandoah Health District construction permit for well and onsite septic — essentially every parcel in the county relies on private well and septic, as there is no public sewer and only limited public water (Town of Monterey water serves the town footprint), (7) floodplain development permit if any portion of the parcel is within the FEMA Special Flood Hazard Area along the Jackson, Bullpasture, Cowpasture, or South Branch Potomac headwater systems, and (8) land-disturbance / erosion-and-sediment-control permit for projects exceeding the state E&S threshold.
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
- 24487
Post Office
- 12258 Cowpasture River Rd S, 24487