Upvc windows - when to replace them?

[Ginzjam]

I thought my 20 year old windows are fine, but apparently lots say they need to be replaced. Why would that be if they still work fine and done have any issues other than just looking a bit old?

Who's said they need replacing?

If lots of people are talking about your windows, they must be in a bit of a state. Are they misted up or draughty?

People looking to buy it say they need replacing, as do the door to door salesmen (no surprise!)

They aren't misted up, they look in good condition from a distance but closer up you can see they are weathered. But they aren't draofty at all and close tight so dont see how new ones would make that much difference?

People looking to buy a house will want to pick faults to negotiate a lower price. Door to door salesmen are just that, salesmen. Of course they are going to tell you to replace.

Can you do anything about them looking weathered, since they are otherwise ok? Specialist cleaning for the frames?

Ha, salesmen will try anything. We recently had all new windows and one came to the door. I gave him short shrift, but then he said 'well, how about a conservatory then?'
Op if you windows all operate as they should, and are not misted up (ours were terrible) then they are fine. You could always try cleaning the frames with a upvc cleaner, but they do tend to discolour a bit anyway in the sun. Don't worry about it.

Older ones won't be as energy/heat efficient as new ones. It's not just draughts, there's the thermal efficiency of the glass/frames too, where heat is also lost. There's also the security aspect - some of the older ones are a lot easier to break the locks or remove the glass. Without knowing the age/material/style etc it's impossible to say whether there'd be much of a benefit.