The concept of yin and yang is the first principle of Feng Shui. It is often described as the shady [yin] and sunny [yang] side of a mountain.
Yang represents the active principles in nature exhibited as sun, heat, day, summer, motion.
Yang also symbolizes male and the force of heaven. Yin represents the passive principle in nature exhibited as moon, cold, night, winter, and stillness. Yin symbolizes female and the earth’s force. With Feng Shui we strive to balance our environment. If yin and yang are not balanced in a space, these imbalances produce all kinds of negative emotions and physical effects. A few simple examples – I see people who complain about being depressed and lack motivation, generally these people spend far too much time in dark places [too yin]. I also see clients who spend all day in office spaces that are far too yang – fluorescent lighting, too many windows that creates an overly bright environment, walls painted white and a lot of movement. If a room is too dark bring in more light, if a room is to bright keep blinds or curtains closed.