Obviously in the original enterprise it's 3-4 floors high but fairly small in width, but in the new films it looks the size of a football field and about 15 floors high. It must take up a huge amount of space on the ship.
Click here for diagram. My idea of where everything is. The positioning of the shuttlebay, engineering, bridge and plaza is concrete although the sizes may be a little off. The turbine placement is based on the zoom-in when Kirk and Scotty transwarp-beam over in STXI, and the curved ceiling where they materialize. Communications (where Kirk found Uhura in STXI) is located behind the deflector dish, as per Chekov's dialogue in Into Darkness. I'm guessing the new warp core is next along from the shuttlebay and engineering. We see them launch a ship from shuttlebay 2 in Into Darkness. As per the Star Trek: The Art of the Movie book and Star Trek bluray "Starships" feature, this Enterprise is 725m/2380' in length, far bigger than the version of the ship in The Motion Picture (305m/1000')
Link doesn't work, King Daniel. Anyway, the Enterprise is much bigger in this timeline, and engineering takes up pretty much the whole engineering section, as far as I can understand. I actually like the "design", myself, because that's what engine rooms look like: you need access to the machinery.