Alger

Hardin County administers three overlay-style layers that affect ADU feasibility: (1) a countywide floodplain regulation -- the county is the NFIP floodplain administrator for unincorporated territory, and a new FEMA FIRM/FIS update for Hardin County went through public-comment open house in November 2022 and into the formal adoption pipeline shortly thereafter; the Scioto River rises in Hardin (just north of Roundhead Township) and the Scioto plus its tributaries are the principal mapped SFHAs in the county; (2) state-managed water-resource exposure on the southwest corner of the county -- Indian Lake's northern shore reaches into Stokes Township in Logan County and the Indian Lake watershed (including Logan-Hardin border townships) carries elevated Health Department scrutiny following the March 14, 2024 EF-3 tornado that struck Russells Point and the lake's resort communities; (3) National Register historic resources -- Hardin County has seven National Register listings (per the NPS list complete through 2025-03-28), the most prominent of which is the 1915 Hardin County Courthouse in Kenton (NRHP 1979-03-21); historic-district design review is administered municipally where it exists (chiefly in Kenton's downtown), not at the county level. Hardin is not in a wildfire-WUI regime and has no coastal exposure.

• Hardin County Floodplain Regulations and FEMA NFIP Special Flood Hazard Areas (post-2022 FIRM revision) — Parcels that were Zone X under the prior FIRM may now be within SFHA following the post-2022 revision; pull the current FIRM at intake.
• Indian Lake watershed (Logan County state park, shared border with southwest Hardin) — Practically, Hardin parcels are governed by the county floodplain regulation and the township zoning book; the Indian Lake reference is included so that consumers in the southwest townships understand the watershed context.
• National Register historic resources (county-level inventory; design review administered municipally)
• Hardin County Subdivision Regulations (administered by Regional Planning) — Subdivision regs are not zoning -- they apply even in townships that have not adopted zoning. Lot-split surveys must be by a Registered Professional Surveyor.

Unlike most Ohio counties where building permits are issued at the township level, Hardin County concentrates residential building-permit and electrical-permit intake at the county level through Hardin County Regional Planning, located in the courthouse in Kenton. An unincorporated-Hardin ADU project still has to clear multiple desks: (1) Township Trustees / township zoning officer -- zoning permit, BZA action where needed; (2) Hardin County Regional Planning -- building permit, electrical permit, residential plan review if 2,000+ sq ft under roof (including attached garages and covered decks); (3) Hardin County Health Department -- on-site sewage (HSTS) site evaluation, install permit, and well permit, required before the building permit can be issued for any dwelling or structure with plumbing; (4) Hardin County Engineer -- driveway/culvert (encroachment) permit on county roads, plus floodplain development permit for parcels in mapped SFHA; (5) Hardin County GIS / Tax Map office -- 911 address assignment at lot split. Permit applications are submitted in person at Regional Planning's Suite 130 office; email submissions are not accepted. Electrical contractors registered with the office may use an online portal for electrical permits only.