It is quite common when repairing water damaged windows to find one that begs this question. I have found that if a certain percentage of the window components are damaged then it makes more sense to replace the window. There are several options for replacing windows; you can do a sash replacement, which means leaving the frame and replacing the upper and lower sash. The sash are the two glass panels framed with wood that make up a typical double hung window unit. Most of the time replacement sash can be found that are either identical to the existing windows or so close you can’t tell the difference. Another option is to use a sash insert set which is a separate frame with new sash that fits into the old window jamb/frame. Finally, if the window is damaged beyond utilizing the existing frame there is always entire window unit replacement. This is the most expensive option and will involve interior work as the trim around the inside of the window has to be taken off and replaced.
Fixed sash windows or picture windows(non functioning) are a little bit easier to salvage than double hung windows. It is very common for the sash to rot across the bottom of a fixed sash window. We have come up with a repair that’s considerably cheaper than replacing the entire unit and fixed sash windows are more expensive. We install a PVC or cement fiber overlay across the bottom of the sash which can last 3-5 years easily and buy you some time before you have to replace that expensive window unit. An overlay won’t work with a functioning window because it will impede it’s operation. Glass bead, which is the very small trim on a sash where the frame meets the glass can also be replaced, and PVC is available for it as well.
These are some facts to consider when doing repairs or remodeling to the exterior of your home. There are many high quality windows available now which feature all PVC exterior components, which means you never have to worry about them rotting. New window units also come standard with Low-e(Low light emissivity) glass now. This glass has a tint to it that really cuts down on heat transfer through your windows. Replacing your windows with new rot-proof energy efficient units is definitely a good investment for your home.