The Probuild-constructed 32 St Georges Terrace in Perth has achieved Practical Completion.
The project is a great example of adaptive reuse, and the use of innovative structural design and construction sequencing to minimise the risks associated with large-scale building refurbishment.
The original building on site was built in 1967, when planning regulations and tenants' requirements were quite different to today. The building had been vacant for four years and while not heritage listed, it was part of the historic character of an established legal precinct in the Perth CBD.
The client sought to drastically extend and refurbish the building, doubling its lettable floor area to meet current market needs and PCA A-Grade standard.
The decision was taken to retain the existing concrete frame on the basis of a 'triple bottom line' of potential dividends: commercial, environmental and social. This carried significant risk because of the unpredictability of working with the existing building fabric, particularly in a tall building of this age.
The existing building core was not capable of meeting the structural requirements of the new expanded building and could not accommodate the requisite building services.
A carefully calibrated programme of concurrent demolition and reconstruction was undertaken to meet the contract period, and to address significant architectural, structural and services design and construction challenges.
It was imperative that there be close collaboration between the various design disciplines and the construction methodology undertaken in a precise sequence so that the structural integrity of the building was maintained throughout.
It was necessary to partly demolish and reconstruct the main core, floor by floor, from the ground up.
This enabled building services to be more efficiently incorporated, BCA compliance to be achieved and a new high-speed lift system and secondary stairwell to be threaded within as much retained core structure as possible.
Re-construction in and around the core was staged progressively, with sequential partial demolition and construction of new concrete walls and floors.