Examine how Merricat and Constance see their house.
The original question had to be edited. I would say that at the end of the novel, Merricat and Constance view their home as a new start. The physical description of the house at the end as a castle helps to establish the idea that a new kingdom or type of dominion has become present with just the two sisters. In this, the sisterly bond has constructed a kingdom of a house where a sense of understanding and justice from the evil of the world around them has become evident. Merricat and Constance now see their house as a domain of strength, whereas before they constantly had to fend off threats from the outside world. As the neighbors take to destroying their house as a result of the fire from Charles' pipe, there is a new structure that emerges. For both sisters, it becomes clear that this structure, resembling a castle with turrets, is something like a new kingdom, a distinctive realm where their sisterhood rules over all and ensures that they will no longer be susceptible from the contemptuous condition of the world around them. It is here where I think that both sisters view their house as something in which empowerment results and enables the girls to be free from victimization.