The fire, just before 7am, badly damaged the two-storey Matai St home of well-known Wanaka resident Jolene Fitzharris.
She told the Otago Daily Times she was devastated at the loss of the family home she had owned since 1991.
She credited neighbour Bernadette Costello with raising the alarm.
Mrs Fitzharris and son Peter Nolet, the only occupants of the house, escaped unharmed.
Mr Nolet told the ODT he woke about 4am and found it was ''super cold''.
''There was snow on the hills; it was freezing.''
He lit the downstairs log burner about 4.30am and after a cup of coffee and some television watching went back to bed about 4.45am.
''The fire was going beautifully.''
Just before 7am, he heard some loud banging from the fireplace, followed by banging on the door.
''It was a neighbour [Mrs Costello] walking her dog and then I noticed all the smoke upstairs.''
Mr Nolet ran upstairs to alert his mother, called the fire brigade and began rescuing some of his possessions.
''I just grabbed an armful of clothes ... grabbed my passport ... my wallet, my phone, phone charger, things like that.''
Mr Nolet said the moment brought back memories of the night in 1979 when he and his family had to abandon their house during the landslip in the Dunedin suburb of Abbotsford.
He said he could remember as a 17-year-old running outside and seeing houses on the move, although his family's home was not damaged.
Mr Nolet, who is planning to move to Nicaragua, said the fire was very sad for his mother, who was insured and is now staying with her other son, Greg, and his wife, Dawn.
He speculated an earthquake 10 days ago cracked the log burner's metal flue where it had a ''dog leg''.
''That's my guess anyway.''
He paid tribute to the Wanaka Volunteer Fire Brigade.
''They were awesome. They got there super quick.''
It took 25 firefighters with two appliances about 45 minutes to bring the fire under control.
Although the downstairs part of the house was not affected by the fire, Mr Nolet said it suffered considerable water damage and he believed the house was unlikely to be salvaged.
• An unattended cooking fire at a Ferry Rd house last night sparked renewed safety warnings from the Glenavy Volunteer Fire Brigade.
Two appliances from Glenavy and one from Waimate were called to a well-involved kitchen fire at the house just before 7pm.
Firefighters extinguished the fire, which appeared to have started after cooking was left unattended on the oven range top, leading a firefighter to stress people should remain vigilant when cooking.
The fire was contained to the kitchen and quickly extinguished, but the kitchen sustained significant damage.
No-one required medical treatment.
