Well for one thing, wood and water don’t seem to get along too well. If you have a wood window in your bathroom, there’s a good chance that you’re going to have mold and mildew hanging around somewhere.
I have replaced more water damaged windows that were located within a shower or bath tub area, than any other windows within the homes that I have remodeled. I don’t recommend using aluminum or steel windows in bathrooms either. Vinyl windows seem to hold up the best in bathrooms.
Most wood windows in your bathroom, are going to provide a nice comfortable home for any mold and mildew, especially if there is moisture on a regular basis in the bathroom. Moisture will accumulate on the wood window, even if it isn’t in direct contact with water from the shower.
Any moisture from a warm or hot shower, can accumulate on your wood window sill, that is located within a closed bathroom. This is probably the most common failure for any wood, located within a bathroom that isn’t maintained on a regular basis.
Not only can the wood windows become damaged, if the home is framed with wood, there’s a good chance that the damage can go all the way to the building foundation. Don’t underestimate the power of water and the damage that it can do to wood.
If the wood window is located in the bathroom, but isn’t located within the shower or bath tub area, there is a good chance that these windows won’t suffer as much. However, if your wood window is located within the shower and the shower is used daily, you can almost guarantee that the wood window will become damaged eventually, unless it is maintained properly.
In other words, I don’t ever recommend installing wood windows near your bathtub or shower. Any areas where water or moisture is going to be hanging around on a regular basis, provides a good place for mold and mildew to start growing.