. . . The TOS Enterprise is supposed to be 947 ft/288m long, with 23 decks. At that size, the bridge deck doesn’t fit facing forwards (thanks to the turbolift) and the decks have a maximum ceiling height of 8 ft, less than the actual sets.
Like most movie and TV interior sets, the Enterprise
sets had no ceilings at all. So ceiling height is whatever you want it to be.
Doug Drexler's cutaway:
We saw in Trek TOS that the dome at the aft end of the engineering hull is a flashing navigational beacon. Whose idea was it to put a control room under there?