A 37-year-old man was arrested on Sunday and charged with arson, just hours after the Karikari Fire Brigade, later reinforced by crews from Kaitaia, saved one house but could not repeat that success further along the road.
The Housing NZ home was completely gutted, Detective Sergeant Trevor Beatson said.
"The outer walls are still standing but the interior structure has gone," he said.
Detectives, a scene of crime officer from Kaitaia and fire investigators were combing through the remains on Sunday afternoon, but the suspect had already been arrested.
He was charged with two counts of arson, two of assaulting a female, one of assaulting a child and two of assault with a weapon.