Decorated in purple with accents of wooden upholstery, the Common Room of Papillionlisse is quite possibly the brightest and airiest of the three houses. The largest area of the room is the first thing you see: a space created especially for the visual artists of the house. The windows are wide and open, and shine directly on a large clearing where "golden hour" lasts quite nearly the entire day. A wall made of drawers containing every art supply imaginable is right nearby, along with easels resting against the walls, which makes it a favourite hangout for the artists of this house.

Against the wall that houses the entrance is a large oil painting of the school, commissioned from Claude Monet, an alumnus of this house of artists. Tapping the frame to the tune of the opening phrase of the school song opens a doorway to a small room that is soundproofed, created as a sanctuary for older students studying for their certificate of education.

A hall of portraits, blocked off from the main area only by a sheer curtain, houses a grand piano, and is a space for musicians of all instrumental inclinations to practice or ask their predecessors for advice, artistic or otherwise.

The rest of the common room is lit by a series of chandeliers and decorated with lavish eclecticness, with one wall made entirely of fluttering crêpe butterflies and their indigo-stained wings. Dormitories are accessed via stairwells to the east and west.