3. Building typology

3.1 Building depth

The amount of light available inside buildings decreases inexorably with distance from openings.

In mainland France, and in an unobstructed environment, it is generally considered that only those points of a room whose distance from the façade is less than twice the height from the ground to the top of the opening are within the zone of influence of natural light. Beyond this distance, artificial lighting must be used most of the time to meet lighting requirements (figure 5 ).