Wow, how Did I miss this the first time around- Awesome detailing! 
Some inspiring work! 
@Pandelea_Anca how did you make the windows? Did you just use a single surface or are they solid? I found some weird light bouncing happening when trying to make “solid” windows with the glass BSDF.
The windows are solide, but I separate the mash with the glass material, am I found a node material for glass.
OK, that’s way beyond my understanding of the shader system, but I’ll come back to it!
Thanks for sharing the node material for glass… I’m going to test this out on my windows.
I will share the result here soon.
Very well done! Great job! Love it!
Nice node setup.
I always recommend if you find a node set up like this to go through it one load at a time and try and get a grasp of how it actually works.
By doing this you will be able to create notes like this yourself in the future according to the needs you require
Thanks for the advice Yes, I did this, I analyzed each node, trying to figure it out what changes it produces. Now I have a general idea what can I do with each node, but I have to practice as much as possible.