Robert Frost's "Home Burial" is a poem, so it would be more correct to talk about stanzas rather than paragraphs. It's also difficult to number the stanzas in this poem because in between the stanzas, there are occasional lines of dialogue. Each line may be counted as its own stanza, or alternatively, each section of dialogue might be considered its own stanza. If we take the former approach, then stanza nine is the stanza beginning, "Amy! Don't go to someone else this time." In this stanza, the only reference to the family's house is to the stairs that separate the husband and wife. If we take the latter approach, the ninth stanza is the stanza beginning, "My words are nearly always an offense." In this stanza, the only reference to the family's house is to the "latch" that the wife begins to move in order to leave the house.
In both instances, the stairs and the latch suggest the emotional distance between the two protagonists, the husband and the wife. The fact that one is upstairs and the other is downstairs indicates the distance between them. There is a physical space between them that represents the emotional space that has grown between them.
The reference to the latch also implies the emotional distance in the relationship. The wife has her hand on the latch, about to leave, to "carry" her grief "to someone else." The husband implores her not to leave. The latch to the door of the house thus represents the wife's impulse to leave the husband. Her hand being on the latch suggests that she is ready to leave, but the fact that she doesn't yet open the latch suggests that she is still unable to do so.
Most of the description of the family's house can be found in the stanza beginning with "You can't because you don't know how to speak." In this stanza, there is again reference to the stairs which separate the husband and wife. There is also a reference to the window through which the wife watched the husband bury their dead son. The window serves to emphasize the emotional separation of the husband and wife. It represents a barrier between them.
Also in this stanza, the wife describes the husband, after he has buried their son, standing his spade "up against the wall" of the house, "Outside there in the entry." The reference to the wall emphasizes the idea that there is a barrier between the husband and wife, and this is compounded further by the fact that the husband in this stanza is "Outside," whereas the wife is inside.
In summary, the descriptions of the family's house are significant in that they help to imply the growing, almost tangible divide between the husband and the wife since their baby's death. The window, the stairs, and the latch on the door are all physical symbols of this divide.