How to distinguish the front and back of the house in geomantic omen (the face is the direction after opening the door in the morning)

In the past, houses had a front and a back, with the front facing the sun and the back sitting. The present house is not obvious before and after, so it cannot be said that the present house is not a house; Just as there used to be only carriages without cars, you can't rebuild cars now. We can only think that the traditional concept of geomantic omen is used to evaluate modern residence, and it is the old-fashioned carriage driving technology to guide modern automobile driving technology, which is out of date.