Monroe County

Monroe County is not a State of Ohio Board of Building Standards (BBS) certified residential building department. Under Ohio's opt-in residential-enforcement framework, this means residential plan review and inspection for Residential Code of Ohio (RCO) compliance for one- and two-family dwellings is not actively administered at the county level. A new ADU on an unincorporated Monroe County parcel does not get a county building permit because no county building permit exists for residential work. The functional permit stack consists of: Monroe County Health Department on-site sewage (Household Sewage Treatment System) and private-water permits, FEMA NFIP floodplain development permits where the parcel lies in a mapped Special Flood Hazard Area (the county is an NFIP participant for the unincorporated areas), Monroe County Engineer driveway / right-of-way permits for new access to a county road, 911 address assignment, and township zoning compliance only where the parcel's township has actually adopted zoning under O.R.C. Chapter 519. Inside the villages, the village (typically through a part-time clerk-of-council or building official) administers any local building, zoning, and floodplain permits.

Process overview: Typical workflow for an unincorporated Monroe County ADU: (1) confirm the parcel is outside any incorporated village (Woodsfield, Beallsville, Clarington, Lewisville, New Matamoras); (2) determine the parcel's township and whether that township has a Chapter 519 zoning resolution — for most Monroe townships the answer is no, but Center Township (containing Woodsfield) and the river townships should be checked individually; (3) Monroe County Health Department review for HSTS (septic) sizing and private-water-supply permits where municipal utilities are unavailable, which is the situation for almost all unincorporated parcels; (4) Monroe County Floodplain Administrator review and Floodplain Development Permit where the parcel intersects a FEMA SFHA (Ohio River corridor and the lower reaches of Sunfish Creek, Captina Creek, and the Little Muskingum); (5) Monroe County Engineer driveway / right-of-way permit if a new access cut to a county-maintained road is required (state-route access is permitted by ODOT District 11); (6) 911 address assignment through the county sheriff's 911 coordinator; (7) construction (RCO compliance is the owner's legal duty but is not actively inspected by a county building department, and there is no certificate of occupancy issued at the county level for residential work); (8) Monroe County Auditor parcel update at the next sexennial reappraisal or triennial update.

Impact fees: Monroe County does not levy municipal-style impact fees on residential additions in unincorporated areas. Fees are limited to per-permit fees at the health department (HSTS and well), the county engineer (driveway), and ODOT (if state-route access). Health Department HSTS permit fees should be confirmed at intake — Ohio county health districts revise fee schedules annually under O.R.C. Chapter 3709.

Real-property valuation in Monroe County is performed by the elected Monroe County Auditor (Ohio uses 'Auditor' rather than 'Assessor'). Ohio counties run a six-year reappraisal cycle with a three-year update in between (O.R.C. Sec. 5713.01 and O.R.C. Sec. 5715.24). A new ADU built on a Monroe County parcel is picked up as an improvement to the host parcel either (a) at the next sexennial reappraisal or triennial update, or (b) earlier if visible from the road during the Auditor's field check or reported through a permit (which in Monroe County effectively means a health-department septic permit, since no county building permit exists for residential work). Ohio assesses real property at 35 percent of true (market) value (O.R.C. Sec. 5715.01). Owner-occupants of a principal residence may qualify for the 2.5 percent owner-occupancy credit (O.R.C. Sec. 323.152(B)) and the Homestead Exemption (O.R.C. Sec. 323.152(A)) for owners aged 65+ or permanently and totally disabled. ADU treatment under the owner-occupancy credit depends on whether the Monroe County Auditor classifies the ADU as part of the principal residence or as a separately-occupied unit.

Assessment policy: Ohio assesses real property at 35 percent of true (market) value (O.R.C. Sec. 5715.01). Monroe County's six-year reappraisal and three-year update cycle follows O.R.C. Sec. 5713.01 and Sec. 5715.24; the schedule is published by the Ohio Department of Taxation's Division of Tax Equalization. The Homestead Exemption (O.R.C. Sec. 323.152(A)) is available to owner-occupants aged 65+ or permanently and totally disabled, subject to the means test introduced by H.B. 59 (2013) for new applicants. The 2.5 percent owner-occupancy credit (O.R.C. Sec. 323.152(B)) applies to the owner's principal residence. Whether the credit extends to an ADU on the same parcel depends on the Auditor's classification of the ADU as part of the principal residence (one credit covers both) or as a separate residential unit (credit may not extend to the ADU portion).

Monroe County's principal county-administered overlay affecting ADU feasibility is its NFIP-participating floodplain ordinance, which covers FEMA Special Flood Hazard Areas along the Ohio River corridor (the entire eastern edge of the county) and along the lower reaches of the major tributary streams (Sunfish Creek, Captina Creek, Clear Fork, Little Muskingum River). Beyond floodplain, the most consequential parcel-level factors in Monroe County are not zoning overlays in the regulatory sense but constructability and title issues: (a) the county is one of the most active Utica/Marcellus shale production counties in Ohio, with widespread oil-and-gas leasing, unitization, pipelines, well pads, and compressor stations that constrain ADU siting on the parcel; and (b) parts of the county sit above legacy underground coal workings (Pittsburgh No. 8 seam, plus older Meigs Creek workings), which raises subsidence-engineering and insurance considerations. The county does not maintain a historic-district overlay, a wildland-urban-interface fire overlay, or any coastal-management overlay (the Ohio River is regulated through floodplain rather than coastal-management rules).

• Monroe County Floodplain Management (FEMA NFIP participation) — A new ADU on an 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 — a common ADU planning trap on older river-bottom homes whose pre-improvement market value is low.
• 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 in Monroe County it is one of the most common factors that derails an otherwise-allowed ADU.
• Coal-mine subsidence risk (legacy underground workings) — Not a regulatory zoning overlay — the county does not block construction over undermined ground — but a material constructability and insurance consideration for any ADU foundation on a parcel above legacy workings.