Hello Raziel, how are you, dear dreamer? lol 
First of all, a house represents the sacred center of the dreamer's life; it reflects their state of mind through events and their earthly position in relation to celestial influences. It is the dreamer's life, the continuous fabric of their experience. The known man: if this man was a great love in your life and you separated for serious reasons, he places the dreamer in the same situation in your life right now. However, if this known man is not the love of your life, he becomes a personal symbol that you project onto him.
The street represents your unconscious; you are making a sort of incursion. The street represents a perception coming from unconscious life. Moreover, it is dark… (perhaps something related to the forbidden, unacknowledged by the dreamer.)
The top floor (the last floor) represents color and the way of thinking in relation to what you are experiencing and the effort to adapt to it. Since you find yourself in your dream in front of the house, which is otherwise the facade, this could indicate and inform you about the external aspect of your personality; it is like the mask of the being, the appearance, what seems to be offered. The door and the threshold constitute a degree to cross for you in order to better know yourself. It is about overcoming the prohibitions of social conventions and trying to merge with one's true personality. The windows are our openness to others; they are also our ability to interact with the outside world.
You also mention the number 8 and the number 20 in your dream because you find two numbers in it: The number 8 places the dreamer before an initiatory trial; trials become increasingly difficult each time, adjusting to the degree of evolution… achieved. It is the man facing his thoughts, his actions, and his words in a result that elevates him by one degree each time, provided there is acceptance of his situation. If there is acceptance of these trials, it is victory that is announced; the inspiring breath supports intelligence in order to discover the truth…
The number Twenty manifests the awakening of spiritual life; it does not address the mediocre and inactive man, for it complicates his life. It promises the end of a trial, a long-awaited favor, and the desired professional advancement. Then there is the lady behind the window... this lady, number one (1), is naturally a hidden part of yourself that you will discover if you accept what is currently happening in your life... subsequently, this hidden part of yourself behind the window will be a new starting point for you, a new person, but it demands a decisive spirit. It is the beginning of what will succeed.
Rolande