This is a very common question and would depend on what reasons you’re considering your windows to be replaced. Some of our customers want to improve the thermal effeciancy of their home and if they have old single glazed windows for example. Where this is the case, we would usually recommend complete replacement or partial replacement which involves installing new sashes into your original box frames. There are limitations when installing new sashes into your orignal box frames for example, many old box frames don’t have the space to be able to accomodate new sashes with thicker double glazing, therefor requiring replcement of the whole window. Where windows have significant rot, we would also recommend complete replacement because although there are options to repair rotten timber, the cost in doing this doesnt usually justify the finished result. Minor rot damage can be repair fairly easily and is sometimes an option we would recommend. If your orginal single glazed sash windows aren’t located in a room you spend a lot of time in such as a bathroom or spare bedroom for example and you’re not that concerned about thermal effiency of the glass, a route you might want to take is an overhaul and draft proof service which costs significantly less than a complete replacement. Its always best to speak to one of our team to discuss your reasons for considering replacing your windows so we can advise accordingly.