Multiplex is one of Australia’s leading construction companies who have built iconic buildings and structures in many countries. Circular Quay is famous as the gateway to Australia, and it has been the home to AMP Capital for over half a century. AMP’s existing tower building was nearing the end of its lifespan and in 2018 Multiplex was commissioned to revamp it for use into the future.
The project brief was challenging in that it called for the ‘Adaptive Re-use’ of the existing tower in conjunction with the “gluing on” of a new tower to the North. The new tower was to consist of a series of shifting glass volumes stacked upon each other so as to provide a striking rotating façade. At their maximum the new floor plates cantilever out by 25 metres.
Some unique features of the project were that it incorporated the tallest partial demolition exercise in the world and the new building slabs had to be initially mismatched to the existing so as to allow for calculated differential settlements.  Building work proceeded via a “Jump Start” technique whereby demolition of the existing tower was happening simultaneously with the construction of the new (North) tower. Finally, a tuned mass damper has been incorporated into Level 46 so as to reduce the building’s sway under high wind loads.
Multiplex can rightly be proud of transforming the ‘3XN Architects’ vision into a reality and for giving both AMP and Sydney an outstanding new building which will provide an environmentally and functionally efficient corporate headquarters for many years to come.