Many below ground level rooms are currently only used to a limited extent due to the lack of daylight. The incoming light through traditional light shafts usually prevents full usage of such rooms. Even during daytime, they generally require artificial lighting. That restricts their function to that of storage place. They may not be efficiently used as work places.

.

Old or new light shafts may be refitted as mirror shafts. Due to the geometrically optimized installation daylight may now be delivered at high efficiency into such below ground level floors. It is generally possible to deliver up to twenty times as much light with a mirror shaft compared to a traditional shaft.

The mirror shaft provides for an optical contact to the outside world. Parts of the sky, surrounding trees, neighboring houses are now visible through the mirrors. That additionally enhances well-being.

Instead of the monotony of artificial light, the dynamic interplay of the weather, sun rise and sun set, movement of clouds and the changing color situation is brought into focus. That makes for a pleasant atmosphere in the room.

Overall, it is a proven fact that daylight enhances the wellbeing and health of human beings.