ADU Pass
Madison County
ADU Pass helps homeowners in Madison County, Virginia navigate the permit paperwork for building an accessory dwelling unit. We cover 9 cities and 21 ZIP codes in this county.
Map
County ADU details
County ADU ordinance
Madison County's Zoning Ordinance (Appendix 1 to the Code of Ordinances, adopted February 2013 with subsequent amendments) does NOT define an 'accessory dwelling unit' as a distinct use category. The ordinance permits 'accessory structures' broadly — a detached structure subordinate or incidental to the main building or dominant use of the lot, including barns. Whether a second dwelling unit (with full kitchen and independent occupancy) is permitted on a residential or agricultural parcel turns on the per-district use schedule and on whether the proposed use can be characterized as a tenant or farm-labor dwelling, a guest cottage without independent kitchen, or a Conditional Use Permit-required second principal dwelling. All construction must comply with the Virginia Uniform Statewide Building Code (USBC, 13 VAC 5-63), which sets size, ceiling-height, egress, and other minimum standards regardless of zoning. Confirm current ordinance interpretation with the Zoning and Planning Department before committing to a project pro forma.
County permitting (unincorporated parcels)
A typical ADU-like permit bundle in Madison County includes: (1) pre-application zoning inquiry to determine whether the project qualifies for a by-right accessory-structure path or requires a Conditional Use Permit, (2) zoning permit confirming use compliance and per-district performance standards, (3) building permit with stamped residential plans and USBC-compliant detail, (4) electrical, plumbing, and mechanical trade permits, (5) Virginia Department of Health (VDH) Rappahannock-Rapidan Health District construction permit for well and onsite septic for parcels not served by public water/sewer (essentially every rural parcel; the Town of Madison has limited public water but most county parcels rely on private well and septic), (6) floodplain development permit if any portion of the parcel is within the FEMA Special Flood Hazard Area along the Rapidan River, Robinson River, or their tributaries, and (7) erosion-and-sediment-control / land-disturbance permit. Projects on parcels adjacent to Shenandoah National Park may have visual-resource and tourism considerations but the Park itself is federal land outside county jurisdiction.
County assessor
Madison County real estate is assessed under the supervision of the Office of the Commissioner of the Revenue, an elected Constitutional Officer with a four-year term. The Commissioner administers the land book annually, processes personal-property and business-tangible assessments, processes state income-tax returns, and administers Meals Tax and Transient Occupancy Tax. The periodic general reassessment is contracted to an outside firm. An ADU or second-dwelling addition is captured through the supplemental real-estate-improvement process under Va. Code § 58.1-3292 — the Commissioner of the Revenue receives the building-permit record and Certificate of Occupancy from the Building Department and adds the ADU's assessed value to the parcel's land and improvement base, prorated to the completion date. The primary dwelling is NOT re-valued off-cycle.
Assessment policy: An ADU is captured as a real-estate improvement under Va. Code Title 58.1 Subtitle III Chapter 32. On receipt of the building permit and Certificate of Occupancy from the Building Department, the Commissioner of the Revenue's office initiates the supplemental assessment under Va. Code § 58.1-3292, prorated from the completion date through the end of the tax year. The ADU is added at its assessed fair-market value (typically derived by the contracted reassessment firm using cost-approach residential cost multipliers) on top of the parcel's existing land and improvement value; the existing primary dwelling is NOT revalued off-cycle. There is no Madison-County-specific ADU assessment exemption. Standard Virginia real-estate tax-relief programs (elderly and disabled relief under Va. Code § 58.1-3210 as adopted locally, disabled-veteran exemption under Va. Code § 58.1-3219.5, Land Use Assessment under Va. Code § 58.1-3230 et seq. for qualifying agricultural / forestal / horticultural / open-space land) apply per local-option rules.
County overlays (3)
Madison County administers a Floodplain Overlay tied to FEMA Special Flood Hazard Areas along the Rapidan River, Robinson River, Conway River, and their tributaries. The county is NOT a Tidewater locality and is therefore NOT subject to the Chesapeake Bay Preservation Act — Madison drains to the Rapidan, then the Rappahannock, but sits west of the CBPA jurisdictional boundary. The western county is bounded by Shenandoah National Park federal land along the Blue Ridge crest (Skyline Drive corridor, Old Rag Mountain). Locally adopted Agricultural and Forestal Districts (Va. Code § 15.2-4300 et seq.) preserve farmland on a renewable-petition basis. Madison County has NO designated coastal-commission analog (none exists in Virginia), NO statewide WUI regulatory overlay, and NO seismic-retrofit overlay. There are no FAA Part 150 commercial-airport noise zones reaching the county.
Known county issues (5)
- other — Pre-application zoning inquiry is essential. Applicants should not assume an ADU is permitted by right; the analysis turns on parcel zoning, use schedule, and proposed kitchen / occupancy configuration. Plan for either a CUP cycle (90-180 days) or a creative path through agricultural tenant-dwelling or no-kitchen guest-house provisions where the parcel allows.
- other — ADU pro formas in Madison can support STR-led revenue models if Zoning and Planning approves the use; revenue ceilings are higher than long-term-rental alternatives. Verify CUP / STR registration requirements before locking in a pro forma. Old Rag Mountain trailhead area parcels in particular see peak weekend visitor volume.
- other — ADU pro formas on mountain-foothill parcels should budget for AOSS septic ($15k-$40k incremental) and pre-construction geotechnical evaluation. Steep-slope site work can dominate the construction budget. Initiate VDH Rappahannock-Rapidan Health District onsite-sewage application early.
- other — For small accessory projects (storage sheds, minor improvements), confirm whether the project falls on the Improvement List — this can streamline the permit path. For ADU-scale projects, the Improvement List does not apply; building permit and (where required) zoning permit are both needed.
- policy-review — Applicants should confirm the current ordinance text with the Zoning and Planning Department rather than relying on prior summaries, and should be alert to General Assembly session outcomes in any year when an ADU preemption bill is introduced. A pre-application zoning inquiry is strongly recommended before architectural or engineering investment.
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.