During the first season of Star Trek The Next Generation, there was never a full-time chief engineering officer for the Enterprise-D. Originally the producers thought that most of the action would take place on the bridge and would rarely go to other areas of the ship, including engineering. The bridge officers would call over the intercom to the other areas and have some voice actor say "Yes sir!" and so forth to save money on new sets. Gene Roddenberry disagreed with this idea and had a change made to the shooting script for the pilot episode "Encounter at Farpoint" to include a scene in engineering; otherwise no engineering set would have been built at all. That set the stage to bring in a new character to act as the chief engineer. Well, it didn't quite work out as planned at first.
My edit must not have gone through. I forgot to add that I was wrong and it wasn't Roddenberry and edited my comment, but it didn't go through to you fast enough I guess. Sorry.
Okay. The idea that they didn't want to film in Engineering really confused me. Because Encounter At Farpoint made a big show of Picard walking the entire set from top to bottom.
It makes a lot of sense that Roddenberry himself vetoed that idea.
I'm guessing Paramount producers in this case, but it's hard to know. It seems to me that Maizlish was more about just doing things his way rather than saving the studio money.
And in the end, they just redressed one of the movie sets as Enterprise-D Engineering and saved money anyway.