In Poe’s short story, special emphasis is drawn to the house that the Ushers live in. In this story, there are two ways of looking at the house; the first way would be to acknowledge the house as a sentient being that shares the life-force of the inhabitants of the house. Throughout the short-story, the house mirrors the condition of its inhabitants – Roderick and Madeline Usher. The house is dilapidated and on the verge of collapse, much like the inhabitants of the house who become afflicted with a serious physical condition (in the case of Madeline Usher) and a psychological impairment (as is in the case of Roderick Usher). The house, despite its state of disrepair sustains itself up until Madeline attacks Roderick, upon which the house collapses. Once the lives of the two Ushers are extinguished the house in turn looses its life-force and crumbles.
The second way of looking at the house would be as a metaphor. This time the word ‘house’ means lineage, and owing to the ruinous nature of the house, and the Usher household not having any enduring branches, we can conclude that the Ushers have been passing down their genes incestuously from generation to generation – when at last only the twins Roderick and Madeline Usher remain. By now a considerable amount of harm has already affected the Usher genome, and its final inhabitants display the two major symptoms of inbreeding – physical and mental impairment. The final blow to the Usher ancestry however, occurs when Madeline attacks her brother. This final act of hostility symbolizes a union between the siblings, a final union that instantly leads to the destruction of the “house” and thereby the dynasty of the ushers.
One can only speculate that the story is in a way an allusion to Poe and his greatest fears – after all Poe did marry his cousin.