Athens

Athens County has NOT adopted countywide zoning regulations as of 2026-05-20. This is a county-specific posture, not the state default: Ohio law (O.R.C. Chapter 303) authorizes counties to adopt countywide zoning by Board of County Commissioners action with subsequent voter approval in unincorporated areas, but Athens County has never put a countywide zoning resolution before voters. The county's regulatory presence in unincorporated territory is limited to two narrow ordinance domains: (1) the Athens County Subdivision Regulations administered by the Athens County Regional Planner, which govern lot splits, minor subdivisions, and major subdivisions countywide, and (2) the Athens County Floodplain Regulations administered for the unincorporated area through the same office and the County Engineer, which apply to any development inside a FEMA Special Flood Hazard Area regardless of township zoning status. Outside those two domains, zoning authority in Athens County is exercised at one of two lower jurisdictional levels: each of the County's incorporated municipalities (the City of Athens; the villages of Albany, Amesville, Buchtel, Chauncey, Coolville, Glouster, Jacksonville, and Trimble; and the City of Nelsonville, whose corporate limits sit partly in Athens County and partly in Hocking County) administers its own zoning code under Ohio Constitution Article XVIII home rule and O.R.C. Title 7, and each township that has elected to adopt township zoning under O.R.C. Chapter 519 administers its own township zoning resolution in its unincorporated portion. Athens Township (which surrounds the City of Athens) is the only Athens County township that has adopted township zoning under O.R.C. Chapter 519, originally adopted by voter approval on November 3, 2020 and amended in 2022 and again effective January 3, 2026; its zoning territory covers only a defined geographic district inside the township, not the whole township. The other thirteen Athens County townships (Alexander, Ames, Bern, Canaan, Carthage, Dover, Lee, Lodi, Rome, Trimble, Troy, Waterloo, and York) operate without adopted township zoning, meaning the only land-use rules reaching parcels in those townships are the county Subdivision and Floodplain Regulations plus the statewide Ohio Residential Code (OAC 4101:8) administered by the local certified building department. For accessory dwelling unit purposes, the practical consequence is that whether an ADU is permitted on an Athens County parcel depends almost entirely on which jurisdictional tier the parcel sits in: inside a city or village, the municipal zoning code is controlling; in the Athens Township zoning district, the township resolution is controlling (and per published commentary the township's accessory-building provisions specifically restrict accessory structures from being used as dwelling units, so an ADU requires variance relief from the Athens Township Board of Zoning Appeals); in the other thirteen unzoned townships, there is no zoning prohibition on a second dwelling on a parcel — the project proceeds under building-permit and floodplain review only.

• Athens County Subdivision Regulations (administered by the Athens County Regional Planner under O.R.C. Chapter 711 and O.R.C. § 711.10 county-platting authority)
• Athens County Floodplain Regulations (administered for the unincorporated area through the Regional Planner and the County Engineer under 44 CFR 60.3 and the National Flood Insurance Program)
• O.R.C. Chapter 303 (county rural zoning) — the enabling statute Athens County has NOT exercised
• O.R.C. Chapter 519 (township zoning) — the enabling statute under which Athens Township operates
• Athens County Comprehensive Land Use Plan and Multi-Jurisdictional Natural Hazard Mitigation Plan

State-floor overlay: Ohio has not enacted a statewide ADU preemption or by-right ADU statute (Ohio Constitution Article XVIII home rule; O.R.C. Chapter 303 county zoning; O.R.C. Chapter 519 township zoning; no preemption bill has advanced past committee in the 134th, 135th, or 136th Ohio General Assembly). Athens County's choice not to adopt countywide zoning is therefore unconstrained by any state floor — the absence of county zoning is a permissible Ohio posture.

Athens County's county-administered overlay jurisdiction is dominated by FEMA NFIP floodplain regulation in unincorporated areas. The county does not maintain a separate historic-district overlay at the county level (historic districts where present are city- or village-administered, notably in the City of Athens). The county is inland and has no coastal or shoreland overlay. The Wayne National Forest, the only federally designated national forest wholly within Ohio, has its Athens Ranger District headquartered in Athens County and substantial federal landholdings concentrated in the Marietta Unit and the Athens Unit; while not a county-issued overlay in a zoning sense, the federal forest footprint constrains where private development can occur in southern and eastern portions of the county. The county participates in the National Flood Insurance Program (NFIP) and administers a Floodplain Damage Prevention ordinance through the Regional Planner and County Engineer for the unincorporated area.

• FEMA NFIP Special Flood Hazard Areas in unincorporated Athens County — A new ADU in a mapped SFHA must be elevated with its lowest floor at or above the Base Flood Elevation. The 2023 triennial reappraisal flagged numerous parcels along Sunday Creek and the Hocking River as floodplain-affected, and FEMA's National Flood Hazard Layer should be consulted for the parcel-specific SFHA delineation before ADU project planning.
• Wayne National Forest — Athens Ranger District — The federal-forest footprint is the largest constraint on where new construction can occur in the eastern and southern townships of Athens County. Parcels available for new ADU construction are concentrated in valley-floor and ridge-line private inholdings around the unincorporated communities.
• Current Agricultural Use Valuation (CAUV) parcels — CAUV recoupment is a material project cost on any ADU built on previously enrolled agricultural land. The recoupment is calculated as the difference between CAUV-valued taxes and full-fair-market-value taxes for the prior three tax years on the converted portion.

Athens County does not operate a single combined building-and-zoning department for unincorporated territory, because the county has no countywide zoning to enforce. Building-code enforcement under the Ohio Residential Code (Ohio Administrative Code 4101:8 for one- and two-family dwellings) is provided through a certified building department; for much of Athens County unincorporated territory, residential building-code enforcement is delivered by the City of Athens Code Enforcement / Building Department on contract or through County Building Code Standards through the regional building department arrangement common to small Ohio counties. The Athens County Regional Planner's office (15 South Court Street, 2nd Floor, Athens, OH 45701) is the central intake point for any project that touches the county-administered domains: subdivision review, floodplain development permit, and coordination with townships and municipalities about jurisdictional reach. The Athens County Engineer's office administers road right-of-way work and culvert installation on county roads and coordinates floodplain mapping with FEMA. For an ADU-style project on an unincorporated Athens County parcel, the typical sequence is: (1) jurisdictional verification with the Regional Planner — confirm the parcel sits outside any incorporated municipality, identify the township and whether that township has adopted zoning (only Athens Township has, and only in a defined district), and confirm whether the parcel sits inside a FEMA Special Flood Hazard Area; (2) if the parcel is in the Athens Township zoned district, township zoning compliance (and likely a Board of Zoning Appeals variance because the township's accessory-building rules restrict accessory-structure use as a dwelling unit); (3) if the parcel is inside a Special Flood Hazard Area, a Floodplain Development Permit; (4) Athens City-County Health Department review for on-site sewage treatment system (septic) and private water supply — almost all unincorporated parcels rely on private well and septic; (5) building permit application to the responsible certified residential building department under the Ohio Residential Code; (6) inspections (footing, foundation, framing, rough trades, insulation, final); (7) certificate of occupancy and notification to the County Auditor for supplemental assessment.