Athens County

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.

Process overview: For an ADU-style project on an unincorporated Athens County parcel, the realistic process depends on which township the parcel is in: (A) In the thirteen unzoned townships (Alexander, Ames, Bern, Canaan, Carthage, Dover, Lee, Lodi, Rome, Trimble, Troy, Waterloo, York) the township imposes no zoning constraint on a second dwelling, so the project advances through county subdivision review (if a lot is being split), floodplain review (if inside an SFHA), Athens City-County Health Department septic and well review, and residential building permit under OAC 4101:8 with the responsible certified building department. (B) In the Athens Township zoned district, the township zoning resolution applies and per published commentary specifically restricts accessory buildings from being used as dwelling units; a second dwelling typically requires a use variance from the Athens Township Board of Zoning Appeals before any building permit can issue. (C) Inside the corporate limits of any of the Athens County incorporated municipalities (City of Athens, villages of Albany, Amesville, Buchtel, Chauncey, Coolville, Glouster, Jacksonville, Trimble, and the partly-in-county City of Nelsonville), the municipal zoning code is controlling and the county Subdivision and Floodplain Regulations no longer apply; refer to the city-tier research file for each municipality. (D) Any project inside a FEMA-mapped Special Flood Hazard Area requires a Floodplain Development Permit through the Regional Planner regardless of which township or municipality the parcel sits in, with the Hocking River, Sunday Creek, Federal Creek, and several minor tributaries being the principal SFHA drainages in the county.

Impact fees: Ohio law does not authorize residential impact fees of the California/Florida pattern. Athens County does not assess impact fees on residential additions in unincorporated areas. Applicants pay only the certified building department's residential permit fee schedule (typically scaled by project valuation or square footage), the Floodplain Development Permit fee where applicable, the Athens City-County Health Department septic-permit fee, the state-mandated Ohio Board of Building Standards 3% surcharge under O.R.C. § 3781.102, and any required Subdivision Regulation review fee if a lot split is involved.

Real property assessment in Athens County is administered by the Athens County Auditor under O.R.C. Chapter 5713 (real property assessment) and the Ohio Department of Taxation oversight of the sexennial reappraisal cycle (O.R.C. § 5715.24 / OAC 5703-25). Ohio law requires county auditors to perform a full sexennial (six-year) reappraisal with an interim triennial update at the three-year midpoint, both on a schedule coordinated by the Ohio Tax Commissioner. Athens County's most recent triennial update took effect for tax year 2023 (taxes payable 2024); the next full sexennial reappraisal is scheduled to take effect for tax year 2026 (taxes payable 2027). The 2023 triennial update produced an aggregate countywide assessed-value increase of approximately 13.65% with residential and agricultural properties moving more than 20% on average, in line with the broader 2022-2023 Ohio statewide reappraisal cycle that produced similar large jumps in many counties. Ohio assessed value is set at 35% of fair market value by O.R.C. § 5715.01, which is the figure to which the millage tax rate is applied. Athens County has an effective residential real-property tax rate of approximately 1.77% of market value as of the most recently published Lincoln Institute of Land Policy / Ohio Department of Taxation Tax Year 2024 effective-rate tables, materially above the national median of approximately 1.02%. New construction (including a newly built ADU on an unincorporated parcel) is added to the tax rolls through the Ohio supplemental-assessment mechanism: the certified residential building department transmits the certificate of occupancy to the County Auditor, who adds the improvement value to the parcel record effective the next tax year following completion. Ohio's H.B. 920 (codified at O.R.C. § 319.301) provides a partial millage-reduction protection on existing parcels through the reduction-factor mechanism, but the new improvement value associated with an ADU is not eligible for H.B. 920 reduction and is taxed at the full effective rate.

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.