Adair County, IA Building Setbacks & Zoning: Structure Height Limits (2026)

Ordinance No. 4 was adopted by the Adair County Board of Supervisors on June 27, 1986. It reaches only land under the airport zones drawn on the Greenfield Municipal Airport Height Zoning Map. A structure located in more than one zone is treated as being only in the zone with the more restrictive height limitation. The ordinance sets no separate cap for houses; its limits apply to every structure.

The horizontal zone is the land under a plane 150 feet above the established airport elevation, which Section II fixes at 1,360 feet. Its perimeter is built from arcs of 5,000 feet radii from the center of each end of the primary surface. The conical zone climbs outward from the edge of the horizontal surface at a slope of 20 to 1 for a horizontal distance of 4,000 feet. The transitional zone rises at a slope of 7 to 1 from the sides of the primary surface and the approach surfaces. Ordinance No. 9, passed May 17, 1995, restated the approach zone for runways 14, 32, 7 and 25 with an inner edge 500 feet wide, an outer edge of 2,000 feet and a run of 5,000 feet at a slope of 20 to 1.

Section III(e) adds one limit that is not tied to the map: no structure shall be erected in Adair County that causes the Minimum Obstruction Clearance Altitude or Minimum Enroute Altitude to be increased on any Federal Airway in the county.

An owner who wants to build above a limit applies to the Board of Adjustment for a variance under Section VI. A copy of the application must first go to the Greenfield Municipal Airport Manager or Aeronautics Director, who has 15 days to respond. Permit and variance applications are made on a form furnished by the City Zoning Administrator, who administers the ordinance under Section IX.