There are two possible configurations of Ba Gua:
- The Anterior Heaven arrangement (Xian Tian)
- The Posterior Heaven arrangement (Hou Tian)
The first arrangement is not used in feng shui, because it represents the ideal world, perfect harmony, ultimate balance. There is no movement, no interaction, life does not change.
The second arrangement follows the movements of yin and yang, like the living world. The trigrams are placed in such a way that they reflect the cycle of the seasons.
Contrary to Western representations, the South is placed at the top. The North is at the bottom. By construction, therefore, the East is on the left and the West is on the right.
The South represents the summer (symbolised by Fire). If we turn clockwise, Summer gives way first to an inter-season, represented by South-West, of Earth nature, then to Autumn and thus to the 2 trigrams of Metal, West and North-West. The North is Winter, symbolised by the Water element. This water will nourish the wood which, after an inter-season, allows spring to be born: the two trigrams East and South-East thus arrive. The loop is closed, as they say!