A bathroom should not be situated at the South position of the house. The South position of the house represents fire element and the bathroom represents water element. Water will fuse fire. This is inauspicious in feng shui context.
Also, the bathroom could not be situated at the centre of the house. Modern people like to set the tub in the middle of the living room, highlighting the romantic features, but in feng shui point of view, this is a taboo.
First, the centre of the house represent earth element while the bath tub represents water. Water will weaken earth element.
Second, by setting up a bathroom at the centre of the house, it will make repair and maintenance difficult as the water supply and sewage piping will have to go through other rooms.
Therefore, take note of these feng shui taboo when it comes to your bathroom fengshui.
