Tarras Chief Fire Officer Mark Davidson said that was one good thing to come out of the incident.
''Most importantly, no-one got hurt.''
Tarras firefighters attended the fire along with crews from Luggate and Cromwell, and by 9.30pm most of their work had been done.
''The house is largely destroyed, and at this stage we're largely in mop-up mode,'' Mr Davidson said.
He said he had no idea what had caused the fire.
Mrs Purvis' son Ben, who lives nearby, told the Otago Daily Times his brother Sam was attending a ''water meeting'' in Tarras, saw the smoke about 5.30pm and raised the alarm.
Ben Purvis said the family had been farming Cluden Station for five generations and many family memories were lost in the fire.
Mrs Purvis' late husband Neil was a well-known Otago rugby player and an All Black (1976), who died in 2008.
He also bred and owned racehorses. Cluden Creek won the 2004 Wellington Cup.
Cluden Station is a 12,000ha merino sheep farm that was once part of the 140,000ha Morven Hills Station.
Ben Purvis said his father's All Black jersey, Otago blazers and photographs from his time as a player had been destroyed in the fire, as had ''all our kids' stuff'' from when the family lived at the homestead.
The house had been a prominent one in the region, he said.
''If you talk to anyone about it, they would say it was a good house. We always had a good time there.
''It's had a lot of history in it.''
Mr Purvis said his mother would stay with family tonight.
The house was insured but ''at the end of the day there's no price on what it was like''.
Mr Davidson said while access to the house for firefighters was no problem, ''we've had to cart a lot of water a long way''.
''We've had water tankers from Luggate, Tarras, and Alexandra, and appliances from Luggate, Cromwell and Tarras.''
Because the stone and timber home was a two-storey dwelling, firefighters were unable to fight the fire from the inside.
''It's a surround and drown situation.''