Does condensation build up on the inside of your home’s windows during the heating season? If it does, you’re not alone. Winter window condensation is a growing problem in Canada and its root has a surprising origin.

As homes are sealed better against air leakage, natural ventilation to the outdoors is reduced. As a result, indoor air becomes much more likely to contain damaging levels of moisture during winter.

If your windows sweat enough during the heating season to require periodic wiping with a towel, then you have a problem. And this problem goes beyond ruined window-frame finishes and mould growth on windowsills. It includes the very real potential for decay within wall cavities and attics, too. Window condensation can also be a sign of low indoor-air quality which affects your health.