Do you have condensation on the outside of your windows? This simple rule of thumb determines if it's normal, or a sinister warning sign

Large green bathroom with freestanding bath and large window to the back. There is a weeping willow tree wallpaper across the back wall.

Condensation forms on windows when there is a temperature difference, causing water droplets to gather on the surface. If you're wondering whether it's normal for condensation to appear on the outside, our HVAC pros have the answer.

As long as yours clears as the day goes on, it isn't an issue. If it sticks around, combating window condensation on the outside may be an indicator your insulation is failing.