Does your window is located on the sunny side or only receiving reflected light? Geographical location is also important. For example, if you live in Finland, I wouldn't bother much.

All glass except quartz and crystal is a pretty good UV filter, that's why those (aka lens protectors) are one of the cheapest camera accessories and part of why halogen lamps have a second layer 😀

I have seen people tint windows on a house like you would a car window. In my game room I had a heavy duty banner made as a window covering to block light. Was from a seller on Amazon. Just sent them the image I wanted on it.

UV is not the cause of yellowing.
Heat is the cause. This is why yellowing still occurs in a box in the dark of an attic.
Note sunlight is also a source of heat, not just UV.