Great!
I can only assume you were aiming for realism in this piece, so I'll point out some of the obvious details you missed.
1. Proportion. The innards of the building would have to be extremely cramped to express the layout portrayed by the windows and bottom floor doorways. (Remember there would be a stairwell consuming up to a quarter of that buildings volume)
2. The fire escape. Aside from the topmost level looking very unsafe (Where's the railing?), this too is out of proportion. The intention of this type of fire escape being an escape route for *all* floors of the building.
But regardless of these little mistakes, you have not failed in creating an extraordinarily good looking building! Like it has been mentioned, this is definitely the kind of quality you'd expect to see in a newly released video game! Good job!