Condensation appears when moisture in the air hits cold surfaces (such as windows). It forms naturally and isn’t something you should be unduly worried about.
Seeing droplets on the outer panes of your glazed units is a good sign as it shows that your windows are working well. Only if you spot moisture on the inner frames of a double- or triple-glazed unit should you be concerned.
For more information on condensation, please head on over to our Helpful Guides section.