Emergency services were called to the fire in a single storey weatherboard home on Plateau Rd, 40km north of Taupo, just before 6am today.
The family of two adults and three children were woken up by their border collie dog.
"It was a dog that alerted them to the fire," said owner of the 130 hectare farm Tim Karl.
Karl had been heading out to milk the herd when he was informed by a neighbour of the fire in one of the farm's houses.
The father of the family who lived at the house worked on the farm in rural Reporoa.
'There was a fire in a garage and it jumped to the house, there is not much left of the property."
He headed to the property, by which time the shed was "up in flames". Northern Fire Communications shift manager Megan Ruru said Taupo firefighters arrived to find the house ablaze. Fire had stretched 16 by 12 metres.
Karl said the family had made it out ok and were all uninjured. He did not wish to speculate on the cause of the fire as the Fire Service was investigating.
The family didn't have time to grab any possessions and had been left with little, said Karl. They were currently staying with family until alternative accomodation could be found.
"I haven't had much time to think about the damage, I have been working through the process and helping them get on with things."
This is the second fire to destroy a family home in the Reporoa area this month.
Rylee and husband Newton Hinton, and their children aged 12, 9, and 6 lost their home when fire broke out just after midnight on November 3.
They lost everything in the fire that left their house a smoldering ruin and vehicles and a boat destroyed.
After getting out with the family Newton went back into the home where he sustained burns to his legs, feet and shoulders.
He was airlifted to Rotorua Hospital before being transferred to Waikato Hospital.