Scott,
The easiest thing to do is check in the attic and look at the sheathing. If there is any mold growth, you can tread it with a proper mildewicide and make sure that the fan ducting is extended ... read more
In most homes, the neccesity of new windows does not usually crack the top 3 in terms of energy efficiency improvements.
You can usually get more efficiency mileage and bang for your remodeling dollar ... read more