To find out the facing direction, you need to take the compass reading of the front door of your house.
The front door is the criteria of the house facing direction, not the big windows or the driveway.
Once you know your house facing direction (or your house sitting direction), you can define the bagua.
This will allow you to apply the feng shui wisdom in your house in a deeper, truly lasting way, because you are creating a strong feng shui foundation when you work with the bagua of your house.
If you have a question about feng shui, please ask your question at the feng shui forum.