Get matched with top doorbell installation pros in Center, ND

Yes, basement insulation needs a vapor barrier due to its susceptibility to moisture seeping in from the outside of the house. You should install a moisture barrier before you install insulation or purchase insulation that comes prebuilt with a moisture barrier to avoid water damage in your insulation and costly mold and water remediation expenses. 

Air sealing isn't necessary for attic insulation, but it's incredibly helpful since it can help you identify and patch any existing air leaks. Failing to find these leaks before adding insulation can render your insulation less effective, leading to higher energy bills and potentially costly repairs down the line.

Heat lost through uninsulated basement walls can account for up to 30% of the total energy lost through heat transfer to the outdoors. While homes in mild climates won't gain as much benefit from having an insulated basement as those in cold climates, the effects are still noticeable on your energy bill.

Yes, usually you will need some kind of vapor barrier on the exterior walls when the framing is attached to concrete and masonry surfaces.