uPVC windows - when and what to replace?

[Longingforatikihut]

Bought my house last year. All double glazed but couple of windows are misted. These need the glass replacing as a minimum. But how do I know if I need a whole new frames too?

If I ask a firm that sells framed units, they'll tell me I need whole new double glazing because that's what they'll make more money on. But if I ask a replacement glass place they'll tell me to replace the glass as they'll want the business...

I know I need new doors (they're knackered)... But the windows I don't have a clue.

So wise ladies (and the occasional gent) of Mumsnet. School me in uPVC! Please!

Also, well done if you made sense of that.

One more thing... What trades person replaces/repairs tops/roofs of bay windows?

We've just bought a house that has quite a few misted/blown windows. We just got a local window firm out to quote and they measured up the glass only as we only want those units replaced. The frames are older upvc but still in perfectly good condition so there is no need for us to replace them. Getting new handles for all the windows as well and a couple of new hinges on 2 as they are a bit difficult to close.

@parkrunner1977 but how do you know the frames are sound? Is it just they look ok, no cracked plastic and not leaking? I'm assuming the doors were fitted at a similar time but they're knackered (internal mechanism is shot and leaking...)

Yes the frames look fine and are all in good condition. Well fitted and no cracks or anything else obviously wrong with them. To completely replace all the blown windows in full would be a good couple of thousand, the replacement glass units (x 7) are costing about £750 in total with fitting and the new handles etc.

Sometimes locks and leaks can be repaired as well rather than the whole item being replaced so maybe just get the doors checked. You will probably be better off with a local firm rather than one of the big national companies. We have one window that needs a new lock mechanism and they are doing that for us as well.