Which is the True Facing Direction

[myfs_94001]

Dear Cecil
im confused about the Facing Direction of my Apt, i've read books, some say Main Door, some say Balcony.
My Balcony is opposite my Main Door & the Balcony faces the Back of another Apt Block. There is no traffic outside my Main Door as it faces the Main Doors of my two neighbours (but not directly, so no poison arrows). And my these two neighbours' flats' balconies (which is opposite of their Main Door as well - which means Same Facing as my Main Door) face the Playground downstairs. So do i take the Main Door OR my Balcony as the Facing Direction? i know that this is crucial in order to plot the Flying Star Natal Chart accurately.
There's not really any proper entrance to my Building - is it possible for a BUilding to have Two (2) Facing Directions?
Pls advise.
Thks.