Carlo,
I did download your model and saw that "fortunately" (though so to speak not too "wisely") you did not create any more complex geometry from your building so what Tom was suggesting, seems to work:
select (with a left to right drawn selection box) everything that is above your first floor windows (i.e. ceiling between the 2 floors and all above)
Click anywhere in your model with the move tool
Before starting to actually move, hit the up arrow (to lock your move in the blue axis)
start moving but before clicking again, type the exact amount you want to move and hit enter.
repeat the whole thing with the roof and the top ceiling selected in a second run.
You still may need to "reposition" your windows a little bit on the vertical (blue) axis to fit to the "new design".