1. When building on the height, seek to face the flat or lower ground.
As illustrated above this going with the flow has a very practical result. The building itself sits on the mountain and is thus supported by it. Conversely, you will see that entry to and from the building is from the lower ground to the higher and thus going against the flow.
An interesting exercise is to reflect on a building as a human body. Both have feet (foundations), both have skeletons, their super-structures. They have shells or skins. They have hats or roofs. Both have faces. The face can be detected most frequently by the location and direction of the mouth (main used doors) and the eyes (windows or other sources of greatest light and activity).
To further the analogy we might like to consider this action of flow in buildings or units that have no back doors. Literally a case of no back door, no anus.
However in cases where buildings are below the street and which are entered from the higher ground towards the lower, ie. entry to the building goes with the flow, the building itself will be lacking support and may even look as if it is likely to tip backwards downhill from the height.
2. When building on the flat, seek to face the height.
In the illustration above we can see that houses on open flat lands need to face the height of the mountain in order for those entering to be going against the flow of the surrounding and dominating flat land. ie The house faces height when all around is flat.
3. Take the trouble to face the water.
In this injunction we are advised that when building near water we should take the trouble to face the water with the front of the house. This is especially so with the case of the main used door.
Defying the rules
The following illustration shows us the opposite of this and how it clearly defies the principle of going with and against the flow.