I want to upgrade some windows on my parent's house. They are single pane and starting to rot. You can actually feel air coming in on windy days because they don't close tightly. I am trying to take advantage of the 30% tax credit up to $1500 this year, but I just noticed that they recently raised the window standards in order to qualify. It used to be that any energy star window qualified. Now it has to be energy star and the U factor has to be less than or equal to 0.30 and the SHGC less