Windows can be tricky. The price we paid for our dual pane Anlin windows was based on the sum total linear inches of window you are buying, not on the number of windows. Doing all of them at once lowered the total price quite a bit. Our 1979 single pane windows still functioned property, so in reality the new windows were only a cosmetic upgrade. If there is an improvement in noise transmission or energy savings, we have not noticed that. So I would not update windows expecting an improvement. But we knew that as we added onto our house 30 years ago and the windows are dual pane there, and put a dual pane bay window in the kitchen at that time. And we put dual pane windows in the bathrooms when we remodeled 13 years ago. We did not replace the window in the garage, saw no reason to.