Fire and Emergency NZ and the police are treating the fire that destroyed a house in Kaka St, Ahipara, early on Thursday morning as arson.
The alarm was raised at 3.28am and two crews from the Ahipara Fire Brigade fought the blaze, with reinforcements from Kaitaia.
A crew and an appliance from Whangārei arrived later in the morning.
Little more than the rear wall was still standing by the time the fire was brought under control, but firefighters protected two neighbouring properties that were threatened at the height of the blaze.
"It was roaring when we got there," Ahipara's chief fire officer Dave Ross said.