Dear Uncle Dixer: I read the article on figuring out facing direction and the apartment paragraph was useful but still I am not sure.
Both front of building and my apartment door face North. Most activity is in the North (kitchen, bath, and living room) The hall way, which is like a meridian that runs North to South, is the only way to access rooms, so high activity tends to be on the northern end of the hallway. Sunlight is mostly on the South side in my bedroom. I remember reading something Qi energy and sunlight.
So based on the information I have, should North be my facing direction because of high activity versus where I get the most sunlight.
Answer: In your situation it is 2 points for the North and 1 point for the south, so the North is the facing.
The reasoning behind this is the sunny side being South gets one point for Heaven Qi, the entrance for both the apartment building and your apartment from the north gets one point for Human Qi and north being the active side gets one point for Earth Qi. Add them up and you have your answer.