Does it make sense to say "no trees are planted in front of the door, no windows are opened behind the door"?
If a big tree is planted in front of the main gate, it is likely to affect the good luck flowing into the house and bring some influence to the owner. If there is no tree in front of the door, but a window is opened behind the door, the good luck will flow out of the window behind the door when it comes in through the main door. In this way, no matter how auspicious the location of the house is and how good the geomantic omen is, there is still no way to bless the owner of the house. The ancients paid so much attention to good and bad luck that they probably agreed with this sentence very much.
In addition, planting trees in front of the door has a big problem, that is, it will affect people's access, and planting trees in front of the door will also affect the light. There is a big tree in front of the door. Leaves will fall off in winter, making it inconvenient for people to travel in all aspects. The reason why we don't open the window behind the door is that neighbors are likely to hear what they say in their own homes, which is not conducive to privacy protection and the threat of theft. From this point of view, it is practical not to plant a tree door or open a window in front of the door for the convenience of people's home travel and safety.
Generally speaking, no trees are planted in front of the door and no windows are opened behind the door. The high probability comes from the ancient people's superstition of Feng Shui, but it also includes the ancient people's thinking about home safety. Although it seems incredible now, the past probably played a certain role, so everyone will believe it.