Michael Ross, deputy chief fire officer of Dargaville volunteer brigade, said it took crews an hour to get the flames under control and about four hours to ensure the scene was completely safe.
"Smoke alarms save lives - no doubt about it. The house is still standing but only just. It's a total loss."
Mr Bain was at the house investigating yesterday.
He said the fire started in the kitchen but he was not sure what had caused the blaze and was waiting to speak to the occupants.
"They've basically lost everything so they're going to have to start all over again," Mr Bain said.
The fire comes only three weeks after a family of five were left with only the clothes on their backs after their rental property on Pukehuia Rd, east of Dargaville, was destroyed by a fire.