Misted or Damaged Windows
Sadly, glazed units don’t last for ever. Generally you should expect at least ten years life, but 20 – 30 is possible in the right circumstances. Over time the seal deteriorates and moisture is drawn into the unit, with south facing windows more likely to fail first.
The remedy is to replace the glazed unit within the window (NEVER let a salesman tell you, you need a new window). The cost will depend on the size of the unit and type of glass.
Of course glass can get cracked or broken, when we will attend as quickly as possible in relation to the extent of breakage and security of the home.