By Savithri Rodrigo
Sydney, Australia (Commonwealth Union)_AMP Center, which was once Sydney’s tallest tower, was recently named the Word Building of the Year 2022 and the greenest skyscraper as it already exists. Renamed Quay Quarter Tower, the original building constructed in the 1970s was showing aging signs and was earmarked for demolition.
The owners planned on replacing the tower with a bigger, better more energy-efficient version, although the environment costs involved in the process from demolition to new construction was going to be significant. Very aware of the carbon footprint this process would entail, including construction waste and CO2 emissions emitted by heavy machinery, Australian investment firm AMP Capital launched a competition for architects in 2014. The brief was simple: Build a new skyscraper without demolishing the existing tower.
Called the world’s first ‘upcycled’ highrise, the tower is 676 feet tall and houses 49 stories. It retains more than two thirds of its original footprint and structure including beams and columns and 95% of the building’s original core. The transformational architecture was conceptualized and brought to life by Danish firm 3XN, initiating the process which first began by removing unsalvageable parts of the old building and then erecting a new structure and grafting it onto whatever remained, leaving a gap of 4 meters between the new and old structures.
An avant-garde styled glass façade was wrapped around both the original and new building to create a single skyscraper. The upcycling also doubled the building’s floor space which now allows 9,000 people to be accommodated in the building from the original 4,500.
And from an environmental checks and balance perspective, the upcycling process is believed to have saved 12,000 tons of CO2, enough to power the building for over three years. The construction process also reduced the use of carbon-intensive material including concrete and saved up to one year in construction time.
However, the challenges were many: determining whether the existing building matched the original design as high-rises often shrink under their own weight was one. With this shrinking, what happens if the old and new structures become misaligned? Sensors were installed to track every minute movement and fed into the model’s digital twin so that real time adjustments could be made.
From the outside, there is no visible presence of the old AMP Center and even inside, the old and the new have been seamlessly blended. The Quay Quarter Tower has retail spaces and offices and overlooks the Sydney Opera house, better viewed from a series of rooftop terraces.
