How much does attic insulation cost in the US, and what R-value do you need by climate zone?
Most attic insulation upgrades can qualify for a 30% federal tax credit up to $1,200, and ENERGY STAR notes that adding insulation first can keep you from oversizing other efficiency upgrades — but the right R-value still depends on your climate zone and attic assembly, so the cheapest quote is not always the right one.