Construction type of a Copenhagen building

Hi guys. I'm new here, so I don't really know what the usual conduct of this forum is, but here I go.

I have a question of the construction type of this building in the middle of Copenhagen. I have tried to figure out who made it, without any luck.

The thing is that I am going to draw a 3D isometric drawing of the building construction, with focus on the bolt. Do the bolt keep the walls together or do they just have a cosmetic purpose? How many layers of walls are there (probably)? Is this construction called something specific?

 

Thank you for your reply!

This is in Strøget, Copenhagen. The exact address is Østergade 47, 1100 København K.