Why did the owners do this?
Some home owners mistakenly believe that this is a safety upgrade. Notice the door is primarily glass. The owners here are afraid of a burglar breaking the glass, and unlocking the door. Personally, I think its a ridiculous to believe that once the burgle breaks that large glass pane, that he will need to unlock the door at all. He can just walk right in! Small windows placed near the lock is the only situation where this installation is slightly logical. However, if a burglar wants to break into your house, they will find a way. It is more prudent to consider the danger involved.
What is the danger? The danger here is that during a fire, occupants will be panicked, hurried, and may not be able to find or operate the key. Perhaps they know where the key is, but the fire has blocked access to it. The code is quite clear on this issue. All means of egress (ways to get out of the house),such as windows and doors, must be operable from the inside without the use of special knowledge or tools.
What is the solution? Some articles I have read state if you the double keyed lock already, to just leave the key in it, or close by. I disagree wholeheartedly. Remove the lock and install an appropriate one; install decorative grills on small window planes; or redesign the area to not include windows. Nothing is worth more than your family’s safety.