Light on Two Sides
This pattern is shaped by
Problem
A room lit from only one side has a harsh gradient — bright near the window, dark at the back — that makes the space feel like a corridor rather than a room. People unconsciously orient toward the single light source, turning their backs on half the space.
Evidence and Discussion
Every major study of daylighting satisfaction confirms it: rooms with windows on two walls receive more even illumination, offer cross-ventilation, provide multiple views, and are rated as more pleasant, more spacious, and more comfortable than rooms lit from one side. The effect is physiological as well as psychological — bilateral light reduces glare, allows the eye to adjust more naturally, and provides the changing light quality that regulates circadian rhythms.
Therefore
give every room where people spend more than an hour at a time natural light from at least two directions. This can be two walls with windows, a window and a skylight, a window and a clerestory, or a window and a glass door — but the light must come from two distinct directions so that no part of the room is in permanent shadow.