hey maxwell people,
thank you all very much.. actually, i do profit of my student time rigth now, when i had time to model my designs that detailled! as a professional, you got to reduce.. no time!
messire, thanks for the hint.. i am aware of that, but sometimes these last details are forgotten.. you are referring to the gallery interior, no?
hey ivox, "king of brutal rendertimes"!, i like that one!

i really appreciate you having on the board.. you seem to be a very interesting person. always a decent comment for every topic.
these ones are for YODA and all the others interested in glass:

and slightly frosted:
make sure to keep the abbe number high to make the glass clear sooner!
i did use sunlight in the very last shot, otherwise just ambient light: physical sky.
of course you can see through glass. but you are not able to see caustics through a dielectric, meaning: depending on the camera position (ouside) it looks as if glass casts shadows just like a massive material.
if you are on the inside, sunlight does go through glass. it just needs a hell lot of time to show up, cause it´s all caustics! if you let it render long enough, you´ll see.
here´s an overview of the IDI building (don´t look at the water, it´s not good!

):

glass, glass, steel and more glass and steel... ah, i forgot slightly frosted glass!
Romans: Grüße nach München in den Schnee! Thank you as well! Good question:

in cinema 4d you could achieve this "architectural camera" with the camera shift. as the plugin doesn´t support this, you need to render the image larger and then crop it to the desired section.