A pantry
A basement...
A basement is a large room under the ground. A dungeon is a room under the ground.
A circular room in commercial buildings or out buildings is called a round house, in a private house it can be called among other things a turret. A rotunda is a round building or a room in a building, the central hall in the Capitol Building in Washington DC is an excellent example of a rotunda ( round room).
Sacristy
Foyer
It's typically called an armory.That is the Arms Room or Armory.
The space under a staircase is called a spandrel.
The room under the roof is called an "Attic".
The rotunda is the famous room located under the dome of the Capitol. Brumidi painted a fresco painting on the ceiling.
pantry or kitchen
a room or building where scientific work takes place
It would be called the "ATTIC".