If you want to know exactly what is the recommended minimum R-value attic insulation, you can checkthis DOE’s mapand check the exact climate zone your house is built in. When you know that, you can just check this R-value attic insulation chart to see how well you should insulate your...
Use the US map and the chart below to determine recommended attic insulation R-values in your area andhow much attic insulationyou need (source –Energy Star website). How much attic insulation on the floor you need (its thickness) will depend on the insulation type / each one has a diff...