Joshua and Margaret's house is the house where Joshua and Margaret raised Finn, Jake, and Jermaine. It appears in Finn's memory in the episode "Memory of a Memory". A hologram of another room in the house appears in "Dad's Dungeon". In "Jermaine", it is revealed that Jermaine never moved out of the house in order to protect it from the demons trying to take back items of theirs stolen by Joshua.
Joshua and Margaret's house is set atop a hill surrounded with a forest infested with demons. Of the rooms shown, the house includes a kitchen, an entrance room, a hallway, a bathroom, and a basement where Bryce is held captive behind a forcefield. The cellar in which Bryce is held is accessed by a lid-covered hole in the floor. Jermaine says, "Open, you Sissy," causing the lid the hinge down, allowing passage below. The lid appears to be a blue and grey rug.The walls of the house are filled with artifacts of Joshua's. The house is destroyed after Jermaine throws a magical hand, which sets the house on fire and burns it.