The beauty of the exoskeleton was its resilience. “Even if a structural component is damaged or removed,the load can be redistributed very efficiently,” said Takamatsu.
The strongest structure in the world is an exoskeleton:the geodesic dome popularised by architect Buckminster Fuller last century. The American Institute of Architects hated Fuller’s domes initially. But in a dramatic change of mind in 1970,they said these domes were “the strongest,lightest and most efficient means of enclosing space known to man”. They span large distances without internal posts,load-bearing walls or deep beams or trusses.
Sydney architect Dr Melika Aljukic worked with the Zaha Hadid Architects team for a year to develop the facade of the Morpheus Hotel. It was only achieved using the latest parametric modelling,she said.
Aljukic said the Morpheus Hotel project developed a new tower typology featuring the first external load-bearing steel structure with a free-form high-rise exoskeleton and a glass lattice shell.
“The exoskeleton geometry ‘morphs’ from an external flat facade into the central building section to define a 40-storey building with three voids integrated between two vertical circulation cores connected at podium and roof levels,” she said.
This kind of design was only made possible by improvements to computer graphics that introduced algorithmic design programming into computer-aided design,she added.
Companies like New Zealand’s Exxovantage are also adapting exoskeletons for construction workers that also spread a load more evenly. Exxovantage global chief executive Arnaud Daurat said it had developed a range of exoskeletons that increased safety and wellbeing. Roofers who wore one of their suits slept better,were less stressed and were 61 per cent more productive.
The public loves an exoskeleton,said Fraser.
“Everyone’s always fascinated when we lay bare the workings of something. Think of watches with a glass back. It is meant to be inherently honest,to say,‘this is the workings of the building and we don’t need to cover it up’.”
Up to this point,Sydney didn’t have many buildings that used an exoskeleton.
But 1 Shelley Street,designed by Fitzpatrick + Partners for the Macquarie Group about 15 years ago,had become iconic because it put the structure – Sydney’s first diagonal grid (diagrid) – on the outside. It has been used endlessly in commercials,said Fraser.
A Sydney specialist in architectural facades,Troy Donovan – a principal with Prism Facades – expects to see an increase in exoskeletons in Australian architecture and construction.
“We need to put more ‘solid’ into our buildings to reduce energy load on the towers,” he said. By moving the structure to the outside,it reduced the carbon footprint of a building by reducing the use of glass.
Now under construction,Atlassian’s new Sydney headquarters at Central Station byShop Architects and BVN will have a diagrid steel-tube exoskeleton and staggered glass envelope surrounding an internal wooden structure. It will reduce carbon emissions by 50 per cent.
Buildings like the Gherkin (formerly known as 30 St Mary Axe) were,Donovan said,a “really great example of an expressive structure”. Its exoskeleton,complemented by an internal support,winds around the building.
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The Gherkin wasn’t inspired by a vegetable,as most people thought,but it mimicked the lattice arrangement of the Venus’ flower basket sea sponge (Euplectella aspergillum),wrote Caroline Wood inThe Biologist, the magazine of the UK’s Royal Society of Biology. “This exquisite creature is named after its hollow tubular structure (or ‘basket’),supported by a lattice-like skeletonE. aspergillum,” wrote Wood.
Here are some top exoskeletons nominated by architects:
1 Shelley Street,Sydney by Fitzpatrick + Partners with Woods Bagot,designed for the Macquarie Group,is the city’s most recognisable exoskeleton.
The Georges Pompidou Centre,also known as Beaubourg,in Paris,France,by architects Richard Rogers and Renzo Piano,was the city’s most hated building because it clashed with the 600-year-old homes nearby. Now the building attracts three million visitors a year. Like the new Powerhouse Museum in Parramatta,the decision to place the structure and services outside was driven by the need for internal flexibility.
15 Clerkenwell Close,London. Built as a block of eight apartments,including a home for the architect Amin Taha. Fraser said it was interesting because it was a “stone exoskeleton” and a beautiful and unexpected building tucked away in London. “What you see really is the way previous generations used to build,which is the structure – whether it’s brick or stone – is the superstructure of the building. It’s holding the building up,” Taha said in an interview.
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