"We believe the flames went up an interior stairwell, and there was no way we could save it. We did manage to contain it, but that was all we could do."
Fire investigator Craig Bain, who examined the remains of the house on Thursday morning, said he had no doubt that the fire had been deliberately lit.
"None of the circumstances point to it being accidental," he said, adding that he had found no evidence of accelerants, but that did not mean they had not been used.
The fire had started inside the house, on the lower level.
No one was home at the time of the fire, and it's believed the house was owned by a Far North man who used it over summer.
It was the seventh serious house fire in the Far North in the past two months.