There is no threshold for the entrance door, so you have to find a master to install one, otherwise it will be covered with dust.
If there is no threshold, water will flood into the house. In a practical sense, if there is no threshold, water will enter your home unscrupulously when it leaks. It may be that sometimes it rains heavily, so it is particularly easy to enter the house. Even in the high-rise, there will be water on the balcony, so it is necessary to set a threshold on the balcony.
And living in a house without a threshold for a long time will first affect the status of family members, because generally we say that a person or a thing is difficult to do and the threshold is too high, so the threshold is a symbol of status. If your house doesn't even have a threshold, the status of family members will naturally decline.
The threshold can also resist the negative feng shui atmosphere. It is necessary to open the door of the house during the day, so at this time the threshold has become the only dividing line between the house and the outside world. No threshold means that there is no dividing line between the house and the outside world, which will undoubtedly make Feng Shui and Shaqi easily enter the house.