Sharn Stewart was one of four adults and seven children, who included a visiting friend, and three dogs that escaped the blaze which broke out about 3.40am on Monday.
Neighbours raised the alarm when they smelt smoke, but the Totara Tce house was destroyed and another house on the same section was badly damaged by the fire.
Mr Stewart said he managed to save three of the family’s hunting dogs but he could not get to the cage to save the fourth because it was just too hot.
Yesterday, the blended family was still in shock and grieving.
"The dog was lost, he was my best mate. I basically watched him burn," Mr Stewart said.
Tawna Woods, Mr Stewart’s ex-partner and the mother of his daughter who escaped the fire, said losing the dog was "huge" and she had never seen Mr Stewart so upset.
"It does not make it [losing the dog] any easier, Sharn and my daughter have had it since it was a puppy, but we are very, very grateful we are not mourning the loss of people. It could have been so much worse."
She said it was lucky Kylie Stewart, Sharn's sister and who also lived in the house, raised the alarm.
"The smoke alarms were not going off, she just woke up because she heard something and when she looked outside the window it was all orange and underneath the house was fully on fire.
"Any later and the floors where they were sleeping would have just fallen through," Ms Woods said.
Fire Emergency New Zealand Investigation Officer John Smalls arrived on the scene early on Monday.
He spent yesterday planning the investigation and interviewing the residents and neighbours.
He said the main internal investigation into the cause of the fire would start today when another Fenz investigator from Invercargill arrived as well as a private investigator hired by the insurance company.
Mr Smalls said the investigation could finish at the end of today if the cause could not be determined, but if something was found it could go on for weeks or even months.
Ms Woods said the family was living with relatives for the time being and had enough of the basics.
All the children were skateboarders and the Wanaka skateboarding community had been "incredible" providing replacement skateboards and helmets, she said.
A fundraising event has also been organised this Sunday at 2pm at the Wanaka Skateboard Park.
Ms Woods said the family was grateful "to live in a place like this where everyone comes together to help in any way they can".
