Bureaucrats overlooked key safety risks as they cobbled together Labor’s home insulation scheme in just five months.

Former prime minister Kevin Rudd’s “horrendous” timeline for the home insulation program denied bureaucrats adequate time to consider safety risks, an inquiry has heard.

Public servants were given five months to devise the $2.8 billion scheme.

Safety considerations were overlooked as they scrambled to have it up and running by July 1, 2009, a royal commission has been told.

Former environment department deputy secretary Malcolm Forbes, who oversaw delivery, says potential risks would have been properly considered if time wasn’t so tight.

Commissioner Ian Hanger QC asked what was “so magic” about July 1, 2009.

“That’s what the prime minster wanted,” Mr Forbes replied.

Asked why nobody told Mr Rudd it couldn’t be done, Mr Forbes said doing so would have gone against the public service culture, which was to remain positive and get the job done.

Mr Forbes said he did raise concerns about the challenging deadline with former co-ordinator general Mike Mrdak.

“We were flagging early that this was a significant challenge to us,” he said.

A coronial inquest has already blamed the scheme’s rushed rollout for the deaths of young Queenslanders Matthew Fuller, Rueben Barnes and Mitchell Sweeney.

NSW tradesman Marcus Wilson also died installing home insulation.

Mr Forbes said he had never, in his 33 years as a public servant, seen such a short gap between a government program being announced and rolled out, as occurred with the home insulation program (HIP).

“The HIP implementation timeline was horrendous,” he said in a statement to the inquiry.

” … some compromises were made that left risks remaining to achieve the timeline.”

The scheme wasn’t fully implemented until September 2009 but even then inspections were happening slowly.

While 400,000 homes had been insulated by October, only 172 roof inspections had taken place.

The inquiry resumes on Friday.