A room is not a room without natural light.
The first thing that an architect must do is to sense that every building you build is a world of its own, and that this world of its own serves an institution.
Consider the momentous event in architecture when the wall parted and the column became.
Even a room which must be dark needs at least a crack of light to know how dark it is.
In a small room one does not say what one would in a large room.
The nature of space reflects what it wants to be.