Multiplex says the noises in Australia 108 are associated with extreme winds. "In extreme winds, it is natural for some noise to be experienced in any high rise," the company said in a statement. "The noise is also expected to reduce at building completion, when damper tanks will be installed to the top of the tower to reduce building movement." However, in 2015, residents of Multiplex’s 72-storey Prima Pearl tower on Queens Bridge Street in Southbank reported creaking noises of more than 70 decibels – a volume louder than a vacuum cleaner – prompting the construction company to commission research to better understand the issue.

Over a six-month period, Multiplex enlisted steel manufacturer Studco and acoustics company PKA to investigate the source of the noise in the Prima Pearl tower. The researchers cut holes in the ceilings and walls of an affected apartment and set up 24-hour recording devices, then employed audio technicians to scrutinise the data. A hole cut in the ceiling of an apartment in Australia 108 as Multiplex investigates the source of cracking and creaking noises in the tower. Their report, finalised in 2017, concluded that 90 per cent of creaking noises in the tower were the result of incorrect construction techniques. Fifty per cent of the noise was caused by misplaced screws or incorrect wall-to-wall or wall-to-ceiling junctions, and 40 per cent was from products being installed on surfaces for which they were not designed.

The remaining 10 per cent came from metal-on-metal friction resulting from winds. Multiplex’s managing director for Victoria, Graham Cottam, cast doubt on the findings of the 2017 report, saying "they [Studco] obviously didn’t send it to us for proof reading" but added the lessons from Prima Pearl have been incorporated into the construction of Australia 108. Mr Cottam said efforts were under way to investigate the cause of the creaking noises in Australia 108, although the company would not be able to eradicate noise due to cases of "extreme weather". "We do expect creaking. It’s just part and parcel of building," Mr Cottam said.

"We won’t fix the creaking and groaning in extreme weather conditions." He said Multiplex was investigating around 35 noise complaints from residents in the Australia 108 tower and was working to better understand the source. "It’s a fact-finding mission to find out that we might have missed a clip on one of the studs which is causing the trouble. It might be as simple as that. If it’s a clip that’s missing, we’ll install the clip and hopefully that’s the end of the issue." RMIT University expert in property construction, associate professor Priya Rajagopalan, said very tall towers can sway under high wind conditions depending on the stiffness of the building. Sometimes noises can be generated by the vibration of elements within the building, she said.

The Australia 108 tower in Southbank is still under construction. Credit:Luis Enrique Ascui But she said sound levels under Australian standards for sleeping areas should not exceed 35 decibels. For residential units on a major road, the absolute maximum should be 40 decibels. Professor Rajagopalan said it was "not at all" appropriate for residents to be exposed to noises as loud as 70 decibels, especially during the night, and said this could result in health problems for residents. "It’s very unhealthy for short term and long-term. Short-term it can cause lack of sleep, insomnia. Long-term it can cause serious health conditions." Acoustics company PKA's principal consultant, Joel Parry-Jones, says retrospectively rectifying the noises like those concerning residents of Australia 108 could cost hundreds of thousands of dollars and potentially involve relocating residents to allow for major structural works.

"It's not an easy fix," Mr Parry-Jones said. Mr Parry-Jones said creaking noises in high-rise towers can be quite intrusive for residents as in extreme cases the noises can be as loud as a gunshot. "The steelwork might bend and bend and bend with small creaks then it gets to a critical limit and snaps back and it will go bang in the middle of the night, waking everyone up." He said his company was receiving "more and more" calls from construction companies reporting issues with cracking or creaking noises in high-rise residential towers. "I think we need to get onto this because it’s going to be the next fire facade issue."

Residents of the Prima Pearl tower experienced loud creaking noises in 2015. Credit:Leigh Henningham Mr Parry-Jones said there need to be more collaboration in construction from the early stages of development. "And the fact the buildings are getting taller makes it worse," he said. "We’ve had a few wind noise issues where the whole thing gets built then they realise there is wind noise." A resident from Australia 108, who requested anonymity, said the cracking noises were not only heard in times of high wind, although she said they worsened with strong gusts. She said Multiplex technicians have cut holes in her ceiling to investigate the source.