Windows become humid inside, what can be done? Old building (2000)

Extractor fan with exhaust air or recirculation? With recirculation, of course, more moisture remains in the room.

We have the same problem, although our kitchen door is usually closed (because of the pets). The only solution then is simply more heating and ventilation during the few months when it is cold.

Apart from the fact that a double glazing (which I prefer to call single cavity glazing) is by no means fundamentally outdated, window units can certainly also be replaced individually without having to tear out the frame.

When I think that I currently pay 100 euros a month for electricity, the possible savings from this will also have a break-even point that lies beyond the time when the windows are replaced anyway due to aging...