This is a movie and police-procedural TV-show cliche that we all know: The police captain (or insert-your-favourite-law-enforcement-officer) realises he (I can't recall it ever being a she.) has a "situation" involving bad guys inside a building that he needs to get out. He shouts: "Somebody get me the plans to this building!". Minutes later the cops are spreading out the blueprints on the bonnet of the car to find the best entry point.

The Bourne Ultimatum is a random example:

VOSEN: Get an elevation and a floor plan, tic-tac-toe.

In that film, the blueprints were immediately sent to an agent's phone.

I know it is all exaggerated in the movies, but my question is "Is there a morsel of truth to this?"

Is it a legitimate and common police tactic to obtain copies of floor plans before embarking on planned raids? Or is this another item that cops roll their eyes at when they see it on television?

I'd accept it as a "Yes" if it was true in any major city in the world. In the absense of that, I'd (provisionally) accept it as a "No" if there were any official denials from major jurisdictions. Open to other evidence too.