There sure are a lot of important houses in Absalom, Absalom!. We've got everything from big plantation mansions to small cabins to prison-like houses. Who gets to enter a house, and through which door, matters a great deal.
In fact, for Sutpen, being prohibited from entering the Pettibone mansion is a pivotal moment: it's what sets his whole plan in motion. And then he puts everything he has into building Sutpen's Hundred, which serves as a symbol of his dynastic achievement. The house, with its "formal gardens and promenades, its slave quarters and stables and smokehouses" (2.7), reflects his stature and wealth, showing how far he has come from the shack in which he grew up. Meanwhile, the slaves who built the house often sleep outside with no roof over their heads or blankets to keep them warm. And of course, the novel ends – spoiler alert! – with Sutpen's house burning to the ground. If the house is a symbol of his dynastic achievement, well… that one's pretty self-explanatory.
Miss Rosa's character is also reflected in her home, which is colorfully described as having "a grim mausoleum air of puritan righteousness and outraged female vindictiveness" (3.1). Who knew a house could have so much personality? And so much utter bitterness?