Condensation inside double glazing

[SecretOfChange]

Moved house recently and one of the windows in the loft has condensation between the double glazing window panes. Picture attached. How much of an issue is this (beyond aesthetics)? Obviously it doesn't help insulation but how much heat would it actually let out, a little or a lot? Also if I leave it as is for let's say up to a year, would you expect significant further damage? Just trying to prioritise various things in the house that need fixing.

It’s just cosmetic.
FWIW it’ll probably cost less than £100 to replace if not half that. We had a full window pane replaced for £100 but a few years ago.

This happens sometimes, there are lots of companies who will replace just the glass if you're happy with the frame. We recently had three window panes replaced with new glazing and it was £80 per window (standard sizes).

The double glazing has blown, it means the seal has broken and the insulation won’t be a effective. Check to see if it’s under warranty, they should replace it if it is.

Your seals have gone. It is not expensive to replace but if you have other more pressing issues to pay for it won’t cause any problems to be left for a year.

You can also have the glass resealed if it is otherwise ok - might work out cheaper than buying a new pane.

This is all great advice, thank you so much. I'll have a window glazing company coming on Friday to measure and let me know how much it'd cost. If it's under £100 then I might as well go for it.

I think the window panes are fine and it's just the seal.