Opal Towers is a high-rise residential complex built near Sydney Olympic Park in New South Wales, Australia. It came to the limelight towards the end of 2018 when residents complained of eerie noises emanating from the structural frame and visible cracks on the walls, beams, and columns. The evacuation followed soon after to pave the way for investigations into the exact cause of the defects and help the concerned engineers to forge the path forward.
Luckily, reports revealed that the defects were mainly rectifiable, meaning the residents would be able to move back in and carry on with their everyday life on the tower. As a result, Opal Towers is safe to occupy, and most residents have already repossessed their units. Here’s a deep dive into how it started and what the developers have done so far:
General information
Some background information about Opal Towers is essential in understanding its controversy and the milestones and resolutions achieved so far. As earlier mentioned, this high-towering residential apartment building sits in the vicinity of Sydney Olympic Park. It rises to a staggering height of 117 m, with 36 floors total, which hosts 392 apartments plus a childcare and retail area.
Bates Smart, a Melbourne- and Sydney-based architectural firm founded in 1853 by Joseph Reed, designed the building, one of the oldest architecture companies in Australia. In addition, WSP, an international engineering services company, completed the structural design. The building’s developer was Ecove, focusing on large-scale residential and retail projects across Sydney. And finally, it was built by Icon Construction, a fully diversified construction services provider which has been in operation since 1861.
Additionally, Icon is a part of Kajima Corporation, a renowned Japanese building company with over 180 years of experience and more than 17,000 workers across 20 countries globally. Indisputably, the main stakeholders in the construction of Opal Towers are industrial powerhouses with a proven track record of excellence.
The apartment block was approved for construction in June 2015 and was completed three years later in mid-2018.
What happened on December 24, 2018?
During the Christmas preparations’ climax in 2018, around 2 PM on December 24, residents reported loud banging noises coming from the building’s structural frame. The maintenance crew quickly traced the eerie noise to a pronounced crack on the 10th and 4th floors. But aside from that, they discovered several other exposed panels and gaps, mainly concentrated on these two floors.
Thinking it was something more dangerous, police and fire brigade pried open the emergency exit door using heavy equipment and evacuated 300 people from the Opal Towers and another 3,000 people living within a 1-km radius from the building. They were, however, allowed to reoccupy the building by midnight of the same day.
What caused the cracks?
A final evacuation was done three days later, on December 27, to allow for a thorough investigation into the buildings’ defects. Seasoned structural engineers from WSP and Icon moved in swiftly to dig into the root of the partial settlement of the beams. Other parties included Cardno, Rincovitch, Slab Scan Pty Ltd, and Mahaffey Associates, all of which boast vast structural engineering expertise.
Preliminary investigations revealed that Opal Towers was overall structurally sound, meaning it couldn’t collapse on its dead weight. Indeed, the structural engineer, WSP, had used a sufficient safety factor to design the columns. In addition, all primary columns had a load-bearing capacity much higher than the design load. In other words, even if external forces were to overload the beams and columns, the building would still have a chance of standing unless the imposed load was extreme.
The inspection committee hypothesized these potential factors that may have resulted in cracking the concrete hob beams, especially those on floors 4 and 10:
Environmental factors
Heavy rainfall, violent winds, and immoderate temperature changes are the usual culprits of excessive loading on buildings. However, weather records across New South Wales in the months preceding the partial collapse showed nothing unusual. As such, the committee ruled out environmental factors.
Inferior quality construction materials
The use of poor-quality materials can lead to local failures in buildings. For such structures, concrete must cure adequately and attain maximum strength. Otherwise, its load-bearing capacity will be less than the design parameters. For Opal Towers, most of the materials the builders used were superior in quality. However, there was one instance where the concrete used for the hob beam didn’t attain the 28-day strength.
Foundation issues
Differential settlement of footings isn’t uncommon. It’s usually a result of the ground softening beneath some of the foundations due to local wetting, forcing part of the building to shift downwards, which leads to cracking.
This wasn’t the case for Opal Towers, however. The committee found isolated cracks only on floors 4 and 10. The differential settlement would have led to more on all the lower floors, starting from the ground floor and moving upwards. Indeed, the geotechnical engineers certified all the 40 footings of Opal Towers suitable for bearing its whole dead load.
Poor Workmanship
Investigations pointed out several inconsistencies between the design and construction. These are the results of the inquiry:
- While the structural engineer specified that the space between the hob beam and the panel should have full grout coverage, the workers only grouted it to 50–70 percent. Such incomplete grout coverage may have elevated the stresses on the hob beams and caused the settlement.
- Two columns had inadequate concrete cover around the rebars. Also, the placement of electrical conduits within the cover zone may have compromised their structural integrity.
- One dowel bar between the hob beam and the panel on the 10th floor was incomplete.
- The designers designed the panels to be flush with the hob beams. But they were thicker by as much as 20 mm in some instances.
- In one panel, Y20 rebars were used instead of the Y28 bars specified in the design.
How Icon rectified the defects
From the inspection reports, it’s clear that no significant structural issue arose from gross neglect or assumptions of engineering principles. On the contrary, only a handful of the tower’s hundreds of beams, columns, and panels had defects. As such, it can safely be concluded that these were errors rather than intentional acts.
The encouraging bit is that Icon Construction admitted the errors and took it upon themselves to fix them. The investigation team made the following recommendations:
- The affected structural components should undergo appropriate rectification to ensure that the final structure meets the design specifications.
- The damaged hob beams must be repaired to ensure they can adequately carry the dead and live loads imposed on them.
- Any structural element that doesn’t meet the standards specified in the National Construction Code (NCC) and the Australian Standard for Concrete Structures (AS36001) is to be rectified accordingly.
- A detailed analysis of load redistribution is to be carried out to ensure the new additions don’t exert undue pressure on the existing load-bearing components.
- All rectification designs and constructions must be assessed for accuracy by experienced independent structural engineers.
- All defect rectification is to be completed before re-occupation of the building.
Icon Construction followed these recommendations to the letter.
What else did Icon do?
Aside from the repair works, Icon Construction responded to the Opal Towers disaster in the following ways:
Funding alternative accommodation
Icon booked the affected residents into hotels, Airbnb suites, and other alternative accommodations to pave the way for the rectification of the defects. In addition, Icon fully paid the rent for every affected tenant wherever they stayed.
Covering relocation and storage costs
Moving from the Opal Towers apartment blocks to the respective alternative accommodations involved hiring loaders and trucks. In addition, the affected residents had to carry their household possessions to ensure their comfort while away from home. Icon covered all these costs instead of leaving the tenants to pay from their pockets.
Additionally, Icon had to empty some units to pave the way for rectification. They stored this property in nearby storage facilities for several months while the building was under renovation and paid all storage fees.
Giving residents allowance for food and incidental expenses
After the Opal Towers incident, residents couldn’t prepare meals as usual at home. It wouldn’t have been fair to let them pay for their meals in hotels, which are usually more expensive than eating at home. After all, it wasn’t their choice.
Luckily, Icon Construction gave them allowances to ensure they didn’t go hungry for the few months they were away from home. Aside from that, they added some cash to cater to incidental expenses like baggage handler fees, phone bills, transportation, laundry services, etc. Finally, and most importantly, the firm fully reimbursed any losses arising from the damage.
Offsetting the increase in insurance premiums
Residents with home insurance coverage had to pay higher premiums for the 12 months after the onset of the Opal Tower tragedy. This is because the building was riskier to stay in than when they took the policies. As it wasn’t their fault, Icon carried the burden and paid for the extra fees demanded by insurers.
Offering support services to residents
It’s normal for displaced residents to inquire about the progress of the remedial works so they can know when they’ll reoccupy their homes. But aside from that, many may have questions about mortgage payments, property safety, and the future. To this end, Icon construction set up a helpline and online portal to get the needed support for the affected people.
Providing a 20-year warranty
As unbelievable as it may sound, Icon Construction provided a 20-year warranty to cover any significant defect in the building. This shows that the company had complete confidence in the structure’s quality. Remember, the Home Building Act of New South Wales requires only a 6-year warranty. Icon’s decision to surpass expectations confirms its commitment to quality and genuine care for people.
This is following Icon’s values:
- Think People: Led by its managing director, Nicholas Brown, the company places people at the top of its priorities, ensuring they remain safe, healthy, and mentally sound.
- Act Together: Icon strives to foster a collaborative spirit in all they do and drives itself by the principle that action speaks louder than words.
- Create Possibilities: The building firm aims at setting new standards for the construction industry.
- Earn Success: Icon makes every effort to be outstanding in all they do through creativity, innovation, and continuous improvement.
Cost implications
From when disaster struck to when the company resettled with all residents, Icon had spent AUD$42million on rehousing, relocating, and feeding the Opal Towers tenants. Luckily, the federal court ruled that the insurers, Liberty Mutual and QBE, should equally share the costs with Icon, meaning each party should pay half the amount.
The resettlement
By December 2019, about one year after the cracks manifested, all residents had been allowed back in the building. This was indeed swift on Icon’s part. Delays in building rectification are all too familiar. But Icon chose to do it differently. At this point, rectification works on the facade and some of the shared hallways were still underway. But the company completed these renovations four months later, in March 2020.
Conclusion
When disaster strikes, especially in the construction industry, it’s normal for the concerned stakeholders to engage in blame games, each trying to justify themselves. However, this wasn’t the case when Opal Towers encountered minor structural failures.
The builder’s main concern was the safety and comfort of the residents, and they did this to their best level. They worked round the clock to ensure all tenants of Opal Towers found alternative housing to stay in as the renovations continued. They also funded their meals, increased insurance premiums, relocation costs, and incidental expenses.
As of now, Opal Towers is one of the safest buildings in Australia, and residents can enjoy their stay without any worries of collapse. It stands as a testimony that disasters can be averted with accountability. All concerned parties must work together to find practical solutions when mishaps occur. Ultimately, issues can be solved, and normalcy resume within a few months.
References
Architecture and Design. “Opal Tower: Design and Construction Issues Uncovered.” January 15, 2019. https://www.architectureanddesign.com.au/news/opal-tower-design-construction-issues-uncovered.
Bleby, Michael. “Opal Tower Builder Icon Claims Victory in $42m Stoush over Costs.” Australian Financial Review, November 11, 2020. https://www.afr.com/property/commercial/opal-tower-builder-icon-claims-victory-in-42m-stoush-over-costs-20201110-p56dec.
Brook, Benedict. “Opal Tower Report Blames Damage on Multiple Design and Construction Faults.” News.com.au, February 25, 2019. https://www.news.com.au/finance/business/other-industries/opal-tower-report-blames-damage-on-multiple-design-and-construction-faults/news-story/4ce37fc18ebe986aab19217ddadc124a.
Career Building. “Opal Tower Is Now “the safest building in Australia.”” Source: https://careerbuilding.com.au/opal-tower-is-now-the-safest-building-in-australia/.
Chang, Charis. “Opal Tower Builder Icon Co Will Provide a 20-Year Guarantee on Works.” News.com.au, December 18, 2019. https://www.news.com.au/finance/business/opal-tower-builder-icon-co-will-provide-a-20year-guarantee-on-works/news-story/ba05fdf7a0f6c0f23449e9855b7de67b.
Independent Advice to NSW Minister for Planning and Housing. “Opal Tower Investigation: Final Report.” February 19, 2019. https://www.planning.nsw.gov.au/-/media/Files/DPE/Reports/opal-tower-investigation-final-report-2018-02-22.pdf?la=en.
World Organization of Building Officials. “Australia: Sydney Opal Tower – News Update.” July 22, 2021. https://wobo-un.org/australia-sydney-opal-tower-news-update/.
