Why is there moisture in the glass of my windows?

This is an indication of a broken thermal seal and a loss of gas from between the panes. The gas is what keeps the windows insulated as it does not conduct or transfer heat. The thermal seal that holds the gas degrades overtime, and air, along with moisture, can creep in between the window panes and create this effect.

Though this is not an urgent repair, as the window will still act as it should, the home will lose the added insulation against the outer elements. Doors and windows make up about half of a home’s heating and cooling needs, and insulated windows are just that one step closer to a more efficient energy system.