Okk ! 

Ok, but I actually don't know GOs. What is that ?

Ok thank you very much !

All right, thank you very much !I was wondering, is there a way to speed up the process of changing windows/doors/walls pen colour or is the manual approach of selecting all doors (for example) and changing the pen colour in Plan/Section parameters (...

Do you mean that it's easier and more efficient to work with pen & styles (model view) and apply it to openings or wall settings like this (attached screenshot) rather than using graphic override? Why and when do we use graphic override then, for hat...