In The Pigman, the theme of "Home" is closely related to "Family." What is a home? John and Lorraine clearly don't feel "at home" in their actual homes, or – before they meet Mr. Pignati – anyplace else, for that matter. They feel most welcome and comfortable in Mr. Pignati's house, but this is a temporary kind of home, and ironically, their "making themselves at home" here results in Mr. Pignati's death. This novel doesn't depict any happy homes at all. In fact, it is the lack of a comforting home that forces John and Lorraine to seek one with Mr. Pignati.
In Mr. Pignati's home, Lorraine and John find a refuge from the discomfort of their own homes.
The home Lorraine and John found with Mr. Pignati was illusory and temporary because it was not based on real ties of kinship and responsibility.