This is actually easy to understand, because the door will block the light, and the balcony is designed with glass, so the light can shine directly through the glass. And I also suggest that when buying a house, don't choose a house with a balcony facing north. The lighting effect of this house should be the master bedroom. The door doesn't face south. It's better for the master bedroom and living room to face south.
In addition to the orientation of the house, the orientation of the room can not be ignored. Try not to choose the direction facing west in the bathroom, because it is humid. The kitchen has a large oil fume, so try not to choose the north direction. The living room and bedroom should choose the south direction as far as possible, so that there is plenty of sunshine and good living comfort. China residents mainly consider "sitting north facing south" when buying a house, which refers to the orientation of the balcony. Because China is in the northern hemisphere, most of the time the sun is facing south, so the balcony facing south will have much better lighting for the house.
The problem of heat has been greatly compensated by the appearance of air conditioning, but the lighting still depends on the orientation of the house. It is precisely because of the hundreds of years since the invention of air conditioning that the global population has started to build many buildings in every community from cold regions to low latitudes, and the direction of the unit entrance of each building is not necessarily the same as that of the community gate. So the orientation of each building will be different. In the wild, the balcony does not necessarily face south, but may face west or east, so the orientation of commercial housing cannot be determined by the location of this balcony. The difference between households is often that there is no ventilation in the north.