Darke County (county seat: Greenville) covers 600 square miles with a population of 51881. Official county website: www.mydarkecounty.com/. This page summarizes the verified building-regulation posture of unincorporated Darke County land; the full 10-dimension scorecard with every source receipt lives on its Freedom Map card.
Darke County appears in the COUNTY section of the BBS Residential Building Department Certification List as 'Darke County (#745) - See Miami County (#413)' — it is a certified residential building department operating under contract with Miami County, so the Residential Code of Ohio IS enforced on 1-3 family dwellings on unincorporated land. The county also requires a zoning permit before the state building permit issues.
The claim above is source-verified (official statute/county documents; URL, direct quote, and date on the full card). Method: how we verify.
No county's freedom erases state law: septic/wastewater permitting (health authority), well permits and water rights (state engineer/DNR), floodplain rules with federally connected financing, and — in some states — state-run electrical inspections. The full card details which of these bite in Darke County and how hard.
The score describes unincorporated county land only. Inside Darke County, incorporated municipalities set their own, usually stricter, rules — including: The City of Greenville, and the villages of Ansonia, Arcanum, Castine, Gettysburg, Ithaca, New Madison, New Weston, Pitsburg, Wayne Lakes and Yorkshire are all listed on the BBS residential list as sub-departments of Darke County (#745) — i.e., the county enforces the RCO inside them too., Greenville has its own building code chapter (Codified Ordinances Ch. 1438) and the City of Greenville administers its own zoning., Six townships — Allen, Mississinawa, Patterson, Richland, Washington, York — are UNZONED, a significant freedom carve-out WITHIN the unincorporated county (though the county residential building permit still applies).. Land inside town limits follows town code.
Building rules are the first question people ask about Darke County — and the easiest one to answer. They're rarely the one that decides it. The full card grades all ten dimensions, every claim quoted from the county's own code.
What the Darke County card answers that this page doesn't:
It's a real map. Click any county in the country and see how it grades — that part costs nothing, and you can compare Darke County against its neighbors before you spend a dollar.
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Last verified 2026-07-11 · Not legal advice — confirm current rules with the county, the state, and a professional before buying or building.