Saint Clairsville

Belmont County is located in eastern Ohio along the Ohio River across from Wheeling, West Virginia, with the county seat at St. Clairsville. Ohio operates under a strong home-rule framework (Ohio Const. Art. XVIII, Sec. 3), and the state has not enacted any ADU preemption or by-right ADU statute. Authority over ADU zoning and permitting in Belmont County is split between (a) the county itself, which may adopt countywide zoning under O.R.C. Chapter 303 but has not done so, (b) Ohio townships in the unincorporated balance, which may adopt township zoning under O.R.C. Chapter 519, and (c) each incorporated municipality (city or village) under its home-rule zoning power. Practically, ADU rules in Belmont County are set by the specific township or municipality, not by the county.

• Ohio Const. Art. XVIII, Sec. 3 (Home Rule)
• O.R.C. Chapter 303 — County Rural Zoning
• O.R.C. Chapter 519 — Township Zoning

State-floor overlay: No Ohio statewide ADU preemption is in force as of 2026-05-20. The Ohio Residential Code (OBBS-adopted IRC with Ohio amendments) sets the building-code floor for one- and two-family dwellings statewide, but use, density, setbacks, parking, and owner-occupancy are local. The county itself retains no zoning authority because Belmont County has not adopted Chapter 303 rural zoning.

Belmont County's two principal county-administered overlays affecting ADU feasibility are (a) FEMA NFIP Special Flood Hazard Areas along the Ohio River and its tributaries (Captina Creek, Wheeling Creek, McMahon Creek, Short Creek), administered by the Belmont County Floodplain Coordinator under the county's NFIP-participating floodplain ordinance, and (b) the legacy of long-wall coal mining and oil-and-gas development across the county, which expresses as subsidence-prone undermined ground and as Utica/Marcellus shale unitization affecting parcel-level surface use. The county itself does not maintain a historic-district overlay; municipal historic districts exist (notably parts of St. Clairsville and Martins Ferry). Wildland-urban-interface fire mapping is not maintained as a binding overlay in Ohio at the county level.

• Belmont County Floodplain Management (FEMA NFIP participation) — A new ADU in a Zone AE Ohio River SFHA parcel must be elevated to or above the Base Flood Elevation per the local floodplain ordinance and 44 CFR 60.3. Substantial-improvement triggers apply when an ADU project's cost exceeds 50 percent of the host structure's pre-improvement market value.
• Coal-mine subsidence risk (long-wall undermining) — Subsidence is not a zoning overlay in the regulatory sense — the county does not block construction — but it is a material constructability and insurance consideration that distinguishes ADU work in Belmont County from ADU work in non-mining Ohio counties.
• Utica / Marcellus shale unitization and surface-use easements — This is a parcel-level title and surface-easement issue rather than a zoning overlay; the county itself does not administer oil-and-gas operations (ODNR has sole-and-exclusive jurisdiction under O.R.C. Sec. 1509.02). It is included here because it is one of the most common Belmont-specific factors that derails an otherwise-allowed ADU.

Belmont County does not operate a county-administered building inspection program for residential construction. Ohio's Residential Code of Ohio (RCO) applies statewide to one- and two-family dwellings, but local enforcement is opt-in: the State of Ohio Board of Building Standards (BBS) certifies local building departments to enforce the RCO, and where no certified local department exists, residential plan review and inspection for RCO compliance are not actively enforced on a parcel-by-parcel basis for one- and two-family dwellings. Belmont County itself is not a BBS-certified residential building department; residential ADU work in unincorporated, unzoned townships proceeds through health-department on-site sewage and water review, county floodplain review (if within an SFHA), 911 addressing, and any applicable township zoning, but without a county-level building permit. Inside incorporated municipalities, the city or village handles its own permits.