We moved into an old building a few months ago and have since had all the windows and some of the doors refurbished – including a suitable alarm system from Somfy (which still doesn’t quite work the way we want it to *g*, at least regarding the outdoor sensor and the gate). Regarding the windows, we had single-pane safety glass installed. It may be over the top, but this is a 350 sqm living area and over 3000 sqm of land, with suitable cars in front of the door (the garage at the back is not finished yet, the garage structure is there, but the interior (except for the foundation, of course) wasn’t finished because of the dampness)... not great when you have doors and windows from 1927 here. Very exciting house here... you have to give it that. :D Besides, in the end it’s not an exaggeration, since even the insurance advised us to have at least lockable window handles installed.