Bulla Grace had been drinking alcohol when he decided to put a pan of oil on the stove, the Rotorua Coroner has been told.
Whether he fell asleep and didn't wake up to the sound of the fire alarm until it was too late, or whether it was that his judgment was impaired will never be known.
An inquest into Mr Grace's death in 2011 has heard that when firefighters arrived at the Dickens St house they didn't think anyone was inside until they came across Mr Grace, in a crawling position, while searching the house. Despite being revived several times at the scene and on the way to hospital, he died a few hours later.
Senior specialist fire investigator Todd O'Donoghue told the inquest before Rotorua Coroner Dr Wallace Bain it was hard to know whether Mr Grace realised the severity of the fire and tried to escape.
Mr O'Donoghue said there was a door to outside in the room he was found, but it was deadlocked and the key was snapped off in the lock.
"The only other path was past the fire."
Mr O'Donoghue said the burns on Mr Grace's body were worse higher up which meant he may have tried to escape past the fire but found it too hot. He said Mr Grace's death wasn't unique.
About 25 per cent of the house fires the New Zealand Fire Service attends involve unattended cooking. With most fire deaths, alcohol is involved.
He said the likely scenario was that Mr Grace put on food to cook, but fell asleep.
While there were four smoke alarms in the house, only one was working - the one closest to the fire, in the room which Mr Grace was in and was still sounding when the fire service arrived.
A post mortem found Mr Grace died of severe burns.
A blood alcohol reading taken several hours after the fire was about 1 times the legal driving limit but was likely to have been higher at the time of the fire.
After the inquest, Mr O'Donoghue told the Rotorua Daily Post that unattended cooking was the biggest cause of fires. He said that in the year to date from July 1, 2012, 42 per cent of house fires in Rotorua were caused by unattended cooking - almost double the national rate. "Compared to national figures it is huge."
He said Mr Grace's death highlighted the need to pay attention when cooking, as well as the importance of having working smoke alarms with the right batteries.