Government surveyors failed to detect major fire risks at a housing complex destroyed in Hong Kong’s deadliest inferno in decades because they were following outdated guidelines that did not require in-person inspections of renovation works, a public inquiry has heard.

The independent committee was told on Monday that illegal alterations to Wang Fuk Court’s emergency passages during the HK$336 million (US$42.9 million) overhaul of the estate’s exterior could have been discovered sooner had authorities updated instructions on inspecting minor construction works in a timely manner.

The hearing also revealed building officials had an inconsistent understanding of inspection rules and applicable legal provisions. A retired surveyor rejected a former colleague’s “unfair” claim that he incorrectly asserted that the use of polyfoam material in renovation works was unregulated.

The blaze that raged across seven of the eight towers at the subsidised housing estate in Tai Po on November 26 was the deadliest in Hong Kong since 1948, killing 168 people and displacing nearly 5,000.

The committee previously heard that manifold fire hazards existed at Wang Fuk Court during the renovation project, including the use of substandard scaffolding mesh and polyfoam boards, as well as the introduction of temporary openings at emergency staircases.

The estate was under the purview of the Housing Bureau’s Independent Checking Unit (ICU), which is subject to the Buildings Department’s oversight, according to a 2022 memorandum of understanding.