I already noticed the owner that everything was just perfect for us. The main issue for us was the outside noise (traffic and roadworks during night :) I can imagine that double glass window can be more effective but it seems that the law forbids to change them which is quite stupid. The little round window is about to crash (it seems that it was already repaired with tape) so what's next if if happens ? I am convinced that there is a solution to find which will of course cost some money but it's necessary to my point of view.