Blocking heat from windows

[DreadPirateRoberts]

Do you have aluminum frame windows? Will the replacement be a retrofit?

How is the insulation in the attic? Is is compressed? I added an extra layer of R-30 and it made a big difference in equalizing the upper and lower level temps. Attic insulation is relatively cheap if you do it your self (but hot and dirty). I think the attic insulation made more of a difference than the dual pane windows.