Whilst some homeowners choose to opt for single-glazing when choosing windows for their internal French doors, there are many benefits to having double-glazed ones. If you're about to order some internal French doors, here are two reasons why you should ensure that their windows are double-glazed.
It could cut down on how much sound travels between rooms that the doors separate
One reason you should consider getting double-glazed doors, even if the doors will be internal ones, is that it will cut down on how much noise travels between the rooms that the French doors separate when these doors are closed. Whilst double-glazed windows in these doors won't provide complete soundproofing, they could prevent the noise that's being made in one room (by, for example, a family member watching TV at a high volume) from being perceived as so loud by those in the adjoining room that the latter cannot focus on whatever they're doing. Instead, those in the other room may only hear a muffled (and, therefore, tolerable) sound that will be less likely to bother them.
This quality of double-glazed internal doors could also be useful on occasions when, for example, you would like to hold a private conversation in one room, without those who are in the adjoining room overhearing it. They could also be beneficial on occasions when one family member wants to take a nap in one of these adjoining rooms, whilst you would like to socialise with some friends in the other, and not have to whisper to avoid waking your relative in the next room.
It could allow you to maintain different temperatures in the adjoining rooms
Another reason you should ensure that your internal French doors' windows are double-glazed is that it could allow you to maintain different temperatures in the adjoining rooms when the doors that separate them are fully closed. This is because double-glazed windows act as insulators that greatly reduce the loss of cold or hot air from a room.
You might appreciate being able to maintain different temperatures if, for instance, one of your family members gets cold very easily and would probably need the adjoining room they spend time in to be well-heated, even on hot days, whereas you would prefer the other adjoining room you're in to be cool when the weather is warm. Provided the two of you keep the doors shut, your relative should be able to run a heater in the room they're in, without the heat from this equipment travelling into the adjoining room you're in and making you feel too hot.