CTBUH Chapter Event

CTBUH NYC Presents: Tall Building Adaptation and the Quay Quarter Tower, Sydney, Australia

Thursday, 05 October 2023 | Arup, 77 Water Street, New York, NY 10005 | New York City

Humanizing the Highrise: How Radical Reuse Will Transform Tower Design into an Environmental and Human Centric Endeavour  

Architecture faces two fundamental and seemingly independent responsibilities: the need to drastically reduce the industry’s carbon footprint, and the need to focus on wellbeing and collaboration. Transformation has the potential – and the case study of Quay Quarter Tower proves – that these responsibilities can be linked, and that towers must rethink their design approach to bring staff back to the workspace and help slow and reduce climate change.  

AIA/CES Credits: 1 LUs

Project Description

As one of the biggest contributors to carbon, and as urban environments become more populated, architecture has a responsibility to become part of the solution to both climate change and social infrastructure. The radical reuse of existing highrises will not just lower embodied carbon but also revitalize urban precincts and improve the socio-economic condition of their surroundings, doing it at a minimum environmental cost impact due to leveraging existing assets.  

Quay Quarter Tower (QQT), a 102,000 square meter commercial office tower, humanizes the high rise by focusing on a social, urban, and environmental transformation of an existing, obsolete tower. This radical reuse demonstrates an alternative to the industry standard of ‘build, demolish, and rebuild.’  

Social: Eschewing the conventions of traditional, uniform highrise design, QQT was developed around a “vertical village” concept, designed from both the inside out and the outside in and with the user experience top of mind.  

Urban: Advances in high rise construction and changes in office/residential needs are rendering 20th century towers obsolete, kicking off a cycle in which assets lose value, owners stop investing, districts deteriorate and lose public attention, ultimately encouraging new development on cities’ outer edges where infrastructure must then be extended. It is a process that is occurring the world over, and one that emits enormous amounts of carbon. By transforming an existing asset and keeping the urban center dense, QQT suggests a means of breaking this cycle.  

Environmental: QQT’s radical reuse involved retaining 65% of the existing structure (slabs, beams, columns) and over 95% of its existing core, grafting new floorplates onto the existing to expand the floor area. This results in an embodied carbon saving of 12,000 metric tons in concrete alone, and reduced the demolition and building programme by 9-12 months, resulting in a cost savings of 150 million AUD. This radical reuse of the existing structure reduces the developments embodied carbon footprint, while it’s more salient design feature, the façade’s external sunshade hood, reduces the solar gain by 30%. This not only gives the building its identity, but also performs by reducing its operational carbon due to lower mechanical loads needed for cooling.   

Number of attendees: 41

Sponsored By:


Associate Principal, Arup
Sydney, Australia
Principal and Property Market Leader, Arup
New York City, United States
Architect, Partner in Charge, North America, 3XN Architects
New York City, United States
Principal, NSW Buildings Group Leader, Arup
Sydney, Australia