Quay Quarter Tower – Sydney, New South Wales. Image credit: Adam Mørk.


Sydney, New South Wales



AMP Capital


BG&E Sydney
Quay Quarter Tower

BG&E were the structural engineers for Quay Quarter Tower (QQT) and worked closely with both the builder Multiplex and developer AMP Capital to transform the existing commercial building at 50 Bridge Street into QQT as it stands today in Sydney’s skyline.



QQT is a hallmark of world-class engineering and ingenuity and has set a global benchmark for adaptive reuse, as well as workplace and mixed-use spaces. The tower is part of Sydney’s newest contemporary neighbourhood – Quay Quarter Sydney, which is built over two city blocks. The neighbourhood includes luxury residential apartments built by Richard Crookes Constructions, boutique retail, green spaces and artisan cafes and will serve as a state-of-the-art destination only metres from Sydney’s stunning harbour foreshore.



BG&E provided structural and construction engineering services (including permanent and temporary works) and materials testing services (including highly complex modelling and analysis) to the highly sustainable commercial tower.

Our team worked collaboratively with consultants and architects to simultaneously design and build, while Multiplex worked in several locations to demolish and rebuild – connecting new floor plates to the existing core of the building, all of which is unique for a building of this scale.

During the upcycle of the existing building, around two-thirds of the towers original core were retained – conserving approximately 12,000 tonnes of embodied carbon.

In a construction world-first, one side of the tower was demolished and reconstructed, while the other side of the tower was retained and refurbished simultaneously – enabling significant environmental and operational efficiencies.

The upcycled QQT now boasts doubled usable area and user accommodations, compared to the original tower – from 45,000sqm to 102,000sqm of usable area, and from 2,500 to 9,000 user accommodations, respectively.

The architectural design by 3XN is based on the concept of a “vertical village” that gives the striking appearance of five separate shifting glass volumes, stacked upon each other.

Some of key features of the redevelopment include:

  • eight-metre high floor in one section of the building with impressive atria connected by spiral stairs;
  • eight-to-15-metre high column grids;
  • composite columns (concrete filled steel tubes);
  • composite floor construction;
  • demolition of approximately one-third of the existing floor plate over full height of building to allow for significant floor plate extension works to be undertaken;
  • irregular/varying floor plates in the building;
  • extending and strengthening of the existing core for lateral stability; and
  • raking columns forming part of complex transfer structures with columns being hung from the roof across more than 20 floors.



BG&E are honoured to see QQT be recognised on the global stage with a slew of 2022 award wins.

QQT were awarded ‘World Building of the Year’ Winner at the 2022 World Architecture Festival (WAF), Lisbon. Selected out of a pool of 161 shortlisted global projects, QQT being awarded 2022 WAF ‘World Building of the Year’ is a testament to both the aspiring client and exceptional team who executed world-first innovations in design and construction when upcycling the skyscraper.

Other notable award wins include:

  • Winner of the prestigious 2022/23 International High-Rise Award.
  • ‘Development of the Year’ Winner, awarded by Urban Taskforce.
  • ‘Project of the Year’ Winner, awarded by Engineers Australia.
  • ‘Best Adaptive Re-use’, ‘Best Innovation’, ‘Best Use of Steel’, and ‘Outstanding Construction’ Winner, awarded by Master Builders Association – New South Wales.



The upcycle of the existing AMP centre tower into QQT has set a new global standard in adaptive reuse, bearing testament to an ambitious team, innovative design, and technical engineering excellence – with the result being a saving of over 12,000 tonnes of embodied carbon when compared to the traditional demolish and rebuild route.

The race to achieve net zero emissions in Australia is underway. With nearly 20% of our nation’s carbon footprint attributed to the construction industry (which equals more than 90 million greenhouse gas emissions annually) – it’s clear we need to transform the way we develop the built environment.

QQT has demonstrated that even the most complex of buildings can be upcycled to extend a structure’s usable life. BG&E looks forward to continuing to provide innovative engineering solutions in the adaptive reuse and multi-purpose development space – challenging the centuries-old raze-and-rebuild ethos and setting a new sustainability standard for the built environment.