223—48.3 (303,404A) Eligible properties. The following properties are eligible for the historic tax credit:
	  1. 	 Property verified as listed on the National Register of Historic Places or determined eligible for such listing through the established procedures of the state historic preservation office (SHPO);
	  2. 	 Property designated as a building contributing to the historic significance of a district listed on the National Register of Historic Places or contributing to the historic significance of a district determined eligible for such listing through the established procedures of the SHPO;
	  3. 	 A property or district designated as a local landmark by a city or county ordinance; or
	  4. 	 A barn constructed prior to 1937.