1. Generally it’s north and south.
2. In ancient times, emperors were very particular about this. Take the Royal Palace for example. There are no even numbers of houses, only odd numbers. The emperor's palace also had nine rooms. Because odd numbers are for living people. Used by dead people when there are even numbers. 9 is the maximum. The south is a fertile land.
3. For the sake of the country, we always sit north and face south. It means to control the world. Which emperor doesn't want to protect his position. So in the room, the head should be in the north and the feet should be in the south. Other people's houses are generally not so particular. And every emperor would be exposed to some Feng Shui techniques when he was in school.