There does seem to be a psychic connection between the physical house that the Ushers live in, and the "house of Usher" as a family line. The house reflects, in its physical form, the fortunes of the family that built it. That family is now down to two people, Roderick and his sister Madeline. Madeline is dying and Roderick seems unlikely to have any children, so it appears the family line will die out with these two.
The "vacant eye-like windows" and the "gloom" of the house foreshadow and describe Roderick Usher. While his eyes are wild and filled with a strange light when the narrator first arrives, after Madeline's death and entombment, we learn that Roderick's eyes become like the windows of the house:
the luminousness of his eye had utterly gone out. ... I beheld him gazing upon vacancy for long hours ...
In other words, he is vacant eyed. Roderick, like the house, is also encased in a sense of gloom. As the narrator explains:
And thus, as a closer and still closer intimacy admitted me more unreservedly into the recesses of his spirit, the more bitterly did I perceive the futility of all attempt at cheering a mind from which darkness, as if an inherent positive quality, poured forth upon all objects of the moral and physical universe in one unceasing radiation of gloom.
It is as if the house and Roderick are one.