My house faces south, and the room in the north faces the gap formed by two tall buildings. Is this feng shui bad? What should I do? Ask for advice.

I don't think you understand anything. As long as you live in the same neighborhood, there is no such thing. You don't understand what this means. It originally refers to the gap between mountains, facing your own house. It's called sky cutting. There is no such thing as long as it is in the same district and there is no natural gap. It is only because of the windy winter in the north that such a house is suitable.