Q. We had a number of thermal windows installed in our home to replace drafty old windows and storm windows, but we are amazed at how much more outside noise seems to penetrate now. How can we find windows that are better at noise reduction?
A. Window ratings normally concentrate on energy factors, but manufacturers or dealers should be able to provide some information on noise reduction. Noise-reduction capability is found in a STC rating (sound transmission classification). The higher the STC, the better the ability to reduce sound transmission. A rating higher than 30 would be considered very good.
However, most good-quality insulated (thermal) window with two or three panes of glass should give you a quieter house than your old windows. It is possible the new windows were not well insulated or sealed around their perimeters, leaving gaps that are allowing noise to enter. If you can feel drafts around the edges of the windows, that might provide a clue.