Unlike rated R movies, R-rated insulation is the best type of insulation for Iowa and Nebraska. In case that term is not familiar, R-Value measures the ability of insulation to resist heat traveling through it. Higher numbers are better on this, so the higher R-value insulations are the ones that will perform the best in the cold Iowa and Nebraska winters. Iowa and Nebraska residents should have a licensed insulation installer install R-value insulations in the the range of R 38 to R60. As you can imagine, the attic is the most valuable place to ensure R-value insulation has been installed, and the recommendation is 10-14 inches depending on insulation type.