Opal Tower is a high-rise residential tower located in the suburb of Sydney Olympic Park in the Australian state of New South Wales. Completed in August 2018, it was built by Icon Construction, developed by Ecove and designed by Bates Smart Architects. The building has 392 apartments, with 34 above ground levels and three levels underground. The building was approved in June 2015 by former Planning Minister Robert Stokes as a major building project. Inconsistencies with the buildings structure have largely been related to under-design and lower quality materials. Development weakness is of increased concern, particularly during Sydney's construction boom to compensate for Sydney's increasing population density. On 24 December 2018 residents reported loud banging noises, cracks and other issues that resulted in an evacuation of the building, and nearby buildings, several hours after midnight. The evacuation eventually totaled over 3,000 people living in or near the building, and led to a report by university deans, with recommendations to create a directory of engineers who work on buildings. In February 2019, New South Wales announced it would change building laws after the evacuation. The new regulations require the registration of designers, engineers, and architects, with building commissioners appointed to audit their work.
Building features The building has 392 apartments, a childcare area, and a retail area. Upon opening, prices for flats ranged from $800,000 to $2.5 million. In February 2019, it was noted that the government owned 43 or more of the units in Opal Tower.
Structural problems
2018 evacuation On 24 December 2018 residents reported loud banging noises, exposed panelling and cracks which mainly affected levels four and 10. A fissure on the 10th floor, millimetres wide, created a loud bang, and police were called at 2:45 pm on Christmas Eve over suspicion of a bomb. 300 people were evacuated. Doors were pried open by police and fire brigade to allow residents to exit the building. Buildings, roads, and a railway station within a radius of 1 kilometre were evacuated. After the evacuation, experts determined the building had shifted between 1 and 2 millimetres. Residents were allowed back in after midnight on Christmas Eve, then evacuated again on 27 December. All residents evacuated from the building were relocated to Airbnb and hotel accommodation over the Christmas and New Year holiday period. By 3 February 2019 Icon ceased paying for food and accommodation outside of the building for all units that were deemed safe by Cardno, an independent engineering firm engaged by the Owners Corporation to oversee rectification work performed by Icon. On 19 February 2019 a 36-page report commissioned by the NSW Department of Planning asserted it was "overall structurally sound." All remedial works were completed by 30 June 2020. Icon's parent company, Kajima of Japan, subsequently provided a 20-year warranty - three times greater than required in the state of NSW.
Causes Developer Ecove denied that there had been any corners cut in construction on 27 December 2018. In January 2019, there were reports that horizontal support beams in the structure were possibly "not strong enough to hold precast concrete panels installed on top of them." At the time, four different investigations were looking into the cracked panels. The original structural engineer, WSP was investigating, as was the NSW Government, the Owners Corporation through Cardno, and builder Icon Construction through Rincovitch Partners. On 25 February 2019, a government report blamed the cracks on design and construction faults. It found the building was structurally sound overall, but that horizontal supports beams were not compliant, under-designed and without proper grouting. 221 of the 400 units were empty then. Minister for Planning and Housing, Anthony Roberts, requested an investigation into the structural, design and material deficiencies. The report published by Unisearch with data formalised by a collaboration of academics from the University of New South Wales. Results showed four key areas of weakness. Firstly, the under-design of the hob beams (a structural element which redistributes weight and creates stability.) and panel assembly allowed for pressure to build, triggering the subsequent cracking and bursting. Secondly, partial grouting of hob beam joints reduced resilience to movement and pressure. Thirdly, the original construction and repairs to concrete panels as well as the choice of lower strength concrete for the hob beams results in the design inconsistencies and structural weakness. Finally, concrete panel damage on Level 10 was the result of the poor structural quality of the hob beams, not direct issues with the panelling. Concluding the building design was not structurally strong enough to hold its weight. Australian tabloid news program, A Current Affair, revealed onsite video footage obtained from a subcontractor. The footage alleged that neglectful behaviour and structurally unsafe material were used in the construction of the residential tower. Concrete slabs, used for the hob beams, were severely cracked and poorly patched up, whilst filler was used to secure slabs that were in poor condition, rather than being replaced, as is protocol. Recommendations in the Interim report suggested steel hob beam reinforcements for the weakened concrete.
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