News and Events

Unique figtree’ office tower opens in Brisbane


7 August 2012

Arup is celebrating the official opening of The GPT Group’s (GPT) ONE ONE ONE Eagle Street – a 54 level six star Green Star Design commercial office tower located within the Brisbane’s Riverside precinct.

At the glittering 1 August opening function, GPT CEO Michael Cameron described ONE ONE ONE Eagle St as Australia’s best office tower, setting new benchmarks in innovation, quality and sustainability. Mr Cameron paid tribute to the key roles Cox Rayner and Arup played in the success of the project.

Arup was responsible for the structural, civil, façade and fire engineering of the spectacular new building which features an innovative structural design inspired by nature. The edges of the tower floors are not supported by conventional bulky vertical columns; instead a seemingly random collection of slender inclined columns grow from the base of the tower, branching and tapering as they rise. The sinuous organic pattern formed on the tower sides is reminiscent of the historic Moreton Bay Fig trees that sit opposite the new building in Eagle Street.

Whilst the ‘fig tree’ columns provide the tower with a unique and striking appearance, the innovative column pattern was not dictated by decoration but driven by science, and the organic nature of the pattern was no accident. The column configuration was computer generated using an algorithm that mimics the way in which plants grow. The clever use of biomimicry resulted in a structure that elegantly and economically spans over the existing Riverside basement carpark and service area without conventional bridging beams. The interwoven and inclined figtree columns also stiffen the tower against excessive sway and twist, allowing the lift and stair core to be reduced in size and offset to the southwest corner of the floor plate. The offset core ensures that all office floor tenants have unrivalled access to river views, and opens up the ground plane to create generous public spaces.

Like all major projects that push boundaries and adopt innovative solutions, ONE ONE ONE presented many technical and logistical challenges for the design and construction team. It was however immensely satisfying to overcome these challenges and we are very proud of the quality of the finished building and the substantial contribution that it makes to the public amenity of the Riverside precinct. The successful completion and leasing of one of the few major towers to be constructed in the midst of the global financial crisis is a testament to the vision of GPT and their design and sustainability aspirations, and to the value of the collaborative and integrated approach adopted by the project team.

- Ian Ainsworth, Principal and Project Director, Arup

Arup worked closely with architect Cox Rayner and contractor Leighton Contractors to integrate the building’s design and construction, cleverly overcoming the logistical and technical challenges of building a major tower with a deep basement within a busy commercial, retail and residential precinct. In addition to the ground-breaking fig tree superstructure, the project featured an innovative ‘up and down’ construction sequence that allowed the tower and basement to be constructed in parallel, saving between six and twelve months compared to the conventional approach of waiting for the basement excavation to be completed before the tower commenced.

Cox Rayner and Arup’s concept for the building was selected by GPT after a design competition. GPT, as both developer and owner of ONE ONE ONE Eagle Street, was impressed with the sustainable fig tree design, and the fig trees are to be celebrated in the completed tower as the centerpiece of the lighting installation devised by artist Alexander Lotersztain. His lighting routine entitled “Breathe” is set to become a popular feature of the Brisbane skyline at night and involves a gentle, pulsing sequence that highlights individual fig tree threads with energy-efficient LED lights, didactically tracing column lines.