Union County (county seat: Creston) covers 426 square miles with a population of 12,138 (2020). Official county website: unioncountyiowa.gov/. This page summarizes the verified building-regulation posture of unincorporated Union County land; the full 10-dimension scorecard with every source receipt lives on its Freedom Map card.
County ordinance list shows NO comprehensive county zoning ordinance and no building code — only single-purpose overlays: floodplain (Ord 39A, 2025), wind-farm placement (Ord 72/73), solar (Ord 74), airport height (Ord 80), plus groundwater/wastewater/well ordinances (31/32/34). No general building permit for a house in the unincorporated county. Score 9.
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 Union County and how hard.
The score describes unincorporated county land only. Inside Union County, incorporated municipalities set their own, usually stricter, rules — including: Creston, Afton, Lorimor / Arispe / Shannon City / Thayer / Cromwell. Land inside town limits follows town code.
Building rules are the first question people ask about Union 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 Union 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 Union County against its neighbors before you spend a dollar.
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Last verified July 2026 · Not legal advice — confirm current rules with the county, the state, and a professional before buying or building.