I'm not sure specifically as I haven't read it. But generally, a novel might be about the lives of the people associated with a salt house. It could explore the history, the culture, and the relationships within that context.
Since I haven't read 'Salt House A Novel', it's difficult to say precisely. However, it could be a story centered around a salt house that delves into themes like survival, community, and tradition. The characters might be involved in the salt - making process, and the novel could show how their lives are intertwined with the salt house. It could also depict the unique environment around the salt house, perhaps a coastal area, and how that affects the story and the people in it.