A cigarette has been ruled out as the cause of a fire that killed 11 family members in a Queensland house three years ago.

A cigarette has been ruled out as the cause of Australia’s worst house fire but a proper smoke alarm would have saved 11 lives, an inquest has heard.

Senior fire investigators say newer photoelectric devices, which can detect a smouldering fire faster, would have spared three generations of the Taufa and Lale families from dying in a blaze at Slacks Creek, south of Brisbane, in August 2011.

But a correctly installed older style ionisation alarm would also have provided the occupants with time to get out, Queensland Fire and Emergency Service (QFES) inspector Bernard Nunn told the inquest in Brisbane on Thursday.

Coroner James McDougall noted the need for a working smoke alarm, following an inquest revelation that the home’s one smoke alarm had been disabled more than a decade before the fire.

Ionisation alarms are known to sound unnecessarily.

“Being annoyed occasionally is a small price to pay, isn’t it, for having a working fire alarm,” Mr McDougall said.

The inquest also heard from former scientific police officer Brad Bardell, who believed the blaze began in the downstairs study used by grandfather Tau Taufa, a smoker.

He claimed both a cigarette and a desk lamp could have been viable ignition points.

But Mr Nunn said “reduced ignition” cigarettes have been the Australian standard since 2008.

He was asked whether he believed a cigarette caused the blaze.

“In this case, no,” he said.

Mr Taufa, one of only three of the 14 occupants who escaped the blaze, has previously told the inquest he often smoked at his desk.

Family friend Louie Naumovski said Mr Taufa would be relieved.

“He’s struggling to keep coming here every day,” he said.

During his evidence, QFES chief superintendent Neil Reid suggested the installation of a fire alarm in every bedroom.

“They (should) be interconnected, and where possible that they be hard wired,” he said.

Under existing laws, Queensland properties must have at least one alarm on each level that has a living space.

Mr Reid said the Australian Building Codes Board was pressed to change the national requirements, but declined in October 2012.

“They look at the cost of a life in Australia, what that figure is. They put a value on it,” he told the inquest.

“They came back and said it’s too expensive.”

However, the code was amended in April 2014, mandating that existing alarms at least be connected with wiring.

“It’s an advantage, but it’s nowhere near enough,” Mr Reid said.

The inquest also heard from pathologist Dr Nathan Milne, who performed autopsies on five of the victims and found the cause of death was smoke inhalation.

The inquest resumes on Monday.