If you own an older house then you may still have the originally wooden window frames fitted. These can add charter to a house but often you find they wood starts to rot and they need to new restored or replaced.
If the wood does become damaged it is important to sort out the issue as soon as possible as it can cause a security issue if left and can even be dangerous if the glass becomes loose.
The cost to replace one large double glazed window is often around £1200-£1500 pounds for a standard UPVC one. If the window is a bay window then it may cost a little bit more. This is a huge outlay to have to find in one go which is why many companies offer finance packages for window replacements. You may have to pay a little more for this or be paying interest but it does allow you to have the windows fitted without having to wait until you have saved up enough money. UPVC windows can also help with insulation and therefor reduce your energy bills. Many of the old style timber frames do not have opening windows which can make the room very stuffy during the summer months.