A Brisbane man who lost his wife and five children in Australia’s worst house fire says he thought his loved ones had escaped when he fled out a window.

The survivors of Australia’s worst house fire hope an inquest into the deaths of their 11 family members will prevent similar tragedies.

Three generations perished when the fire tore through their home in Slacks Creek, south of Brisbane, on August 24, 2011.

A coronial inquest, which began in Brisbane on Monday, is now examining the deaths and considering whether all properties should be fitted with smoke alarms when sold.

One of the first witnesses, Jerimiah Lale, recalled waking to the sight of smoke filling the house.

He told the inquest he left his bedroom to search for an escape after telling his wife and five children to stay put.

It was the last time he saw his loved ones.

Mr Lale described frantic scenes inside the home, as his sister-in-law Fusi Kalau Taufa gathered other children and headed for his bedroom.

By the time he returned to the room, there was nobody in it.

“You could feel the floor, it was really hot, and (there was) smoke inside” he said.

“I thought they (were) already outside, and had jumped from the window.”

Mr Lale fled out a window, injuring his shoulder.

By that time, the house was “covered in fire”.

Outside, Mr Lale found Tau Taufa and Mark Matauaina, who were calling out to those who were trapped.

Mr Taufa’s wife Fusi, daughter and three grandchildren all perished.

He testified that he left his downstairs study just before midnight.

He kissed his wife goodnight, who was sleeping in the lounge room, before noticing smoke seeping through the upstairs kitchen floorboards.

The grandfather attempted to fight the fire, with a garden hose.

Firefighters arrived less than ten minutes after the first triple zero call but there was no prospect of performing any rescues.

The court also heard there was no evidence of any working smoke alarms in the premises.

Mr Taufa testified that one smoke alarm, in an upstairs hallway, had been disabled some time in the 1990s after it went off unnecessarily.

The court heard that during the investigation, a desk lamp from Mr Taufa’s study was considered a possible ignition point.

Outside court, Louie Naumovski from the Logan House Fire Support Network said reliving the tragedy was dragging up raw emotions.

“The family wants a bit of closure, hopefully this will give it to them,” he said.

Over the next two weeks the inquest will hear from police officers, firefighters, eye witnesses and an electrical safety officer.