Depending on which of the hull decorations are actually windows, and whether the windows on the 'shuttle-bay' at the rear span one or two decks, I estimate that if the windows on the 'shuttle-bay' are in-fact single deck windows then it would follow that the ship is approximately 14 decks in height - however, if they are not single deck windows (and by looking at the other hull details that appear to be windows, which are significantly smaller than the windows on the 'shuttle-bay') then it would follow that the ship is approximately 30 decks in height.
I think it probably has a height similar to that of an Intrepid Class (66 metres for 14 decks?) which would make this ship about 230 metres in length if both drawings share the same scale.