JKR: Probably. I hear you. It is the tradition to have four houses, but in this case, I wanted them to correspond roughly to the four elements. So Gryffindor is fire, Ravenclaw is air, Hufflepuff is earth, and Slytherin is water, hence the fact that their common room is under the lake. So again, it was this idea of harmony and balance, that you had four necessary components and by integrating them you would make a very strong place. But they remain fragmented, as we know.
[Interview MuggleNet & The Leaky Cauldron pada JKR 16 Juli 2005]
Ini letak Common Room keempat asrama:
Gryffindor: entrance of the seventh floor
Ravenclaw: Ravenclaw Tower, which is located on the west side of the castle
Hufflepuff: Unknown, but downstairs off the main hall. Cellar-like in appearance
Slytherin: it is located under the lake, low-ceilinged, dungeon-like room with greenish lamps and chair
Common Room Ravenclaw melambangkan udara, Hufflepuff melambangkan bumi, Slytherin melambangkan air, apakah Gryffindor memang melambangkan api?