ADU Pass
Haymarket
ADU Pass helps homeowners in Haymarket, 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
Two-agency permitting: (1) Town of Haymarket zoning approval first (Zoning Administrator Emily L. Kyriazi at 703-753-2600), (2) Prince William County Building Permit. The PWC accessory-dwelling prohibition applies to UNINCORPORATED PWC and does NOT govern within Haymarket town limits. Post-July 2027, SB531 mandates by-right ADUs in single-family zones unless Haymarket adopted a qualifying pre-2026 ordinance.
Cost scenarios
| Scenario | Sq ft | Permit | Build | Total |
|---|---|---|---|---|
| minimum | 200 | $950 | $92,000 | $92,950 |
| 600 | 600 | $1,650 | $276,000 | $277,650 |
| midpoint | 600 | $1,650 | $276,000 | $277,650 |
| maximum | 900 | $2,150 | $414,000 | $416,150 |
Fee breakdown (as of 2026-05)
Permitting process
Viability (permitted uses)
- Long-term rental: with-restrictions Strong long-term rental demand: DC-exurb commuters, growing Western Prince William workforce, proximity to I-66 corridor.
- Short-term rental: with-restrictions Haymarket town zoning governs STRs; PWC transient occupancy tax registration required. Moderate STR demand from DC weekend tourism, wine country (nearby Loudoun), historic-village charm.
- Office rental: no Detached office rental to outside tenants not permitted in residential districts.
- Home office: yes Home occupation permitted under Haymarket zoning.
- Studio / workshop: yes Personal studio is a permitted accessory use.
- Agriculture: with-restrictions Haymarket town is largely residential within incorporated limits; agricultural accessory structures limited.
- Relative support: with-restrictions Multigenerational accessory dwellings allowed pending Town zoning review.
Contacts
Utilities
- Water: Town of Haymarket municipal water (town runs own utility) · 30d connect · $4,200 · separate meter required
- Sewer: Town of Haymarket municipal sewer (town operates own collection; treatment via regional authority) · 45d connect · $9,500
- Electric: NOVEC (Northern Virginia Electric Cooperative) · 30d connect · $2,400
- Gas: Columbia Gas of Virginia or Washington Gas (varies by parcel); propane available for non-mains parcels · 21d connect · $2,200
Property values & taxes
Construction timeline
Realistic total: best 9mo · typical 13mo · worst 20mo
Modular pathway inspectors are occasional with modular
US-15 and I-66 provide major-route access. Tight historic Washington Street side-streets may constrain crane positioning for older town-core lots.
Financing
Insurance impact
HOA prevalence & preemption
Haymarket historic village core has low HOA presence; newer subdivisions around the town (Dominion Valley, Piedmont, Regency at Dominion Valley) have strong active HOAs governing many parcels in the wider Haymarket ZIP 20169.
Regulatory overlays (1)
- historic-district
Haymarket Historic District includes St. Paul's Episcopal Church (one of four pre-1862 buildings surviving the Civil War burning) and post-Civil War rebuilding stock. Town has historic-character architectural review for new construction visible from Washington Street.
Technical envelope (climate & building code)
Climate & energy code
Building code
Amendments:
- Amendment
- Amendment
- Amendment
Contractor market (aggregate)
Legal history (timeline)
Current ordinance: Town of Haymarket Zoning Ordinance, adopted 2022-06-27, last amended 2022-06-27
- 1799-01-01 — Town of Haymarket founded on Skinker land grant (local-ordinance)
Virginia General Assembly granted William Skinker authority to lay out the town in 1799; original plat consisted of 13 streets and 140 lots.
Effect: Establishes Haymarket as a chartered Virginia town with land-use authority. - 1862-11-04 — Civil War burning of Haymarket (local-ordinance)
Federal troops set the town ablaze; only St. Paul's Episcopal Church and three small houses survived. Subsequent rebuilding shaped the current historic-village character.
Effect: Most Haymarket pre-1862 building stock destroyed; current historic district reflects post-Civil War reconstruction. - 1882-01-01 — Haymarket formally incorporated as a town (local-ordinance)
Haymarket became the second town in Prince William County to formally incorporate, in 1882.
Effect: Establishes Haymarket's incorporated-town authority to enact independent zoning. - 2018-01-15 — Town of Haymarket transferred building department to Prince William County (local-ordinance)
Effective January 15, 2018, Prince William County Department of Development Services took over building permitting and inspection for the Town of Haymarket. Town retains zoning authority.
Effect: Two-agency permitting: Town zoning + County building permit. - 2022-06-27 — Town of Haymarket Zoning Ordinance comprehensive update (local-ordinance)
Town adopted updated comprehensive zoning ordinance on June 27, 2022.
Effect: Current operative town zoning code; pre-2026 status may qualify Haymarket for SB531 exemption. - 2026-04-13 — Virginia SB531 signed by Governor Spanberger (state-law)
Statewide ADU by-right mandate; effective July 1, 2027.
Effect: Haymarket's 2022 zoning ordinance may exempt the town from SB531 if its provisions are construed as a qualifying pre-2026 ADU ordinance.
Known issues (3)
- policy-review — Adds coordination overhead; common confusion for owners about which agency to contact first.
- policy-review — Misinterpretation of county code can lead owners to wrongly conclude ADUs are prohibited; Town of Haymarket zoning is the operative authority.
- other — Architecture fees may run 5-15 percent higher for historic-district parcels.
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
- 20168
Post Office
- 14658 Gap Way, 20169