But, in our drive for modernity, we lost fragments of our origin. In our journey towards the future, we weakened our recollection of the past.
This isn’t necessarily a bad thing. Technology and innovation have progressed at such an accelerated pace that some elements of our past have been rendered obsolete. We are not using sundials to tell time anymore; we now can construct tall towers equipped with elevators to take us from one floor to the next with ease.
More often than not, engineers are tasked to make sense of the elements we have today to design and construct the future. Combine accurate planning with solid foundation and best-quality materials, and you arrive at the same time-tested result: a sound and flawless building intended to serve well into the future. What I realised, however, is our ability to bridge the past and the now to turn our buildings into monuments of history. We can continue to preserve our history’s legacy in our quest for modernity.
This was the case for Sydney’s 5 Martin Place. The century-old landmark had undergone three structural developments and remained as sturdy as when it first arose in 1916. And then came the challenge for us to develop it a fourth time.
The most memorable part of this building’s rich past was when it first served as the headquarters of the Commonwealth Bank of Australia, earning the enduring moniker of the ‘Money Box’. In 1933, its first building extension was developed, followed by a second one in 1968. By 1990, the third redevelopment was in the works.
Mathematically speaking, the structural assessment weighed in favour of retaining the heritage site ̶ but the building’s age threatened the feasibility of a fourth upgrade.
Innovative thinking paved the way for Aurecon to solve this challenge. It involved demolishing the 1968 structure and replacing it with a new 20-level building; but since the original 1916 structure and its 1938 extension could no longer bear additional load, 11 levels (approximately 22 metres) had to be cantilevered over the historic building.
Out-of-the-box thinking produced a new free-standing structure that imposed no load on the heritage building, by hanging completely from a simplified V-shaped bracing on four sides of the tower. Ironically, this uses the simple strut-and-tie design approach that is among the first that an engineer learns in engineering school.
Ingenious engineering saved more than 450 tonnes of steel; enabled the creation of a new atrium that brought natural light into the large floor plates; and helped achieve a 5-Star Green Star status and 5.0-star NABERS rating for the iconic building.
5 Martin Place proved there is wisdom in keeping the past. Keeping and celebrating decades upon decades of its historic architecture today adds an asset to Sydney’s highly congested central business district. Keeping the heritage building base undisturbed has created a monument to Martin Place’s cultural and commercial weight.
Despite it being by far the most complex project I’ve been involved with, in terms of engineering gymnastics of any building, the ‘smarts’ of this world-first structural solution are all hidden. But it shows that harnessing a past built on solid rock to rebuild the now could prove to be your wisest engineering decision, yet. As you might come to learn quite unexpectedly, some stones are better left unturned.
This article was first published on 9 May 2017 via LinkedIn.