Innovation in construction often arises when engineers face new challenges. That’s the case when revitalisating and renovating culturally significant, heritage-listed buildings, which can provide a powerful test of an engineer’s flair.
The recent build of Western Australian Museum Boola Bardip — a dramatic design that links contemporary structures with historic buildings at the Perth Cultural Centre — had several graduate engineers and graduate construction management personnel involved in the complex project.
The outcome has been such a positive one that it’s had a powerful effect on their careers. So says Peer Ahamed, Construction Manager at MultiPlex and winner of a WA AIB Professional Excellence Award for his work on the St John of God Murdoch Hospital in Perth.
Ahamed was a Project Manager on the Boola Bardip build, responsible for procurement and delivery of the project.
“From the graduate who was just getting exposure, to the project manager, to the construction manager and everybody else, every one of us had a lot of learning during this project,” he said.
“Particularly in terms of stakeholder management, design, procurement of special materials — some parts of this project were a real eye-opener for us. Everybody learned so much.
“There were four engineers who were really project engineers. They were working on coordinating the design, but they also got involved with the execution of the project. That was a fantastic experience for them, and for all of us.”
The challenges were multifaceted.
“We have this particular site — an existing museum — which included four heritage buildings with its oldest, the Old Gaol, dating back to the mid-1800s. And so we had to combine the heritage with new construction without damaging or changing any of the existing building,” Ahamed said.
“In terms of construction engineering, we’ve got a 17m long cantilever that sits on top of a heritage building, housing one of the exhibition halls. That is an enormous structural element which, logistically, was so difficult. Plus, we only had two streets that we had access to, to do the work.”
As described on the website of Perth engineering firm BG&E, which provided structural and civil engineering services on Boola Bardip, the column-free gallery spaces are elevated 15m above the ground over clear, external pedestrian areas.
“Gallery floors [were] designed for total imposed loads of 14.5 kilopascals and 120 kilonewtons concentrated loads with stringent deflection and vibration acceptance criteria,” the BG&E case study said.
“Gallery floors comprise composite steel floors spanning 20m on two two-storey-high fabricated structural steel trusses. These floors are supported by fabricated steel trusses, located within wall lines over storey heights and vary in depth, of between 7m and 15m.”
There was no such thing as a simple solution on the project, Ahamed said.
When additional structural members were required and the team had to go into the fabric of the heritage building, slots of brickwork had to be opened up without causing any damage.
The structure then had to be temporarily held in place while the structural members were inserted, then the brickwork painstakingly replaced without any evidence of the work being done.
For the structural work to enable the construction of roof trusses spanning up to 45 m, instead of birdcage scaffolding, the team developed a scaffold on wheels that was guided along a train track of sorts.
“Much of our innovation followed a trial-and-error process,” Ahamed said.
Ahamed said he believes engineering work on or around a culturally significant building needn’t cost too much more, in terms of dollars or time, compared to a similar non-heritage project — as long as the project brief is clearly priced within specifications and there are no changes. It might require more resources, but what changes is the detail in the planning.
“There are a lot of things to be managed,” he said.
“On the resources side, there is a slight increase compared to normal commercial buildings. For a similar, non-heritage job I might have about 17 staff, but on this project I had about 22. So, it’s a slight increase, but not a drastic one.”
The value in heritage
Engineers go to a lot of trouble to ensure heritage buildings remain in their intended state. That’s important, said Michael Taylor FIEAust CPEng (Ret), Chair of Engineering Heritage Australia’s national committee.
“Heritage and the story of the past is so important because you can learn so much from it,” he said.
“People want to know where things came from and how they came to be what they are today. It’s very valuable.
“At Engineering Heritage Australia, we tell history too. We’re involved in trying to recognise and help conserve those items that demonstrate our history.
“There is moveable and immoveable heritage — buildings, bridges and dams are immoveable. But tractors and steam engines and aircraft are moveable. You can put moveable items together in a museum, but immoveable items must be preserved in place.”
History of democracy
For that reason, in 1988 when Australia’s Parliament House became Old Parliament House, the building was not simply locked up and forgotten. A plan was put in place for its upkeep.
More recently, when it was partly repurposed as the Museum of Australian Democracy, the work done to create the exhibition spaces had to respect the requirements of this National and Commonwealth heritage-listed building under the EPBC Act.
“The Museum of Australian Democracy is only approximately a third of the building’s footprint,” said Chris Grebert, Head of Facilities, Capital Projects, Heritage and Security at Old Parliament House.
“We’re guided by our Heritage Management Plan 2021–2026. Working with engineers is not as simple as getting a BIM model and working from that. The engineers often work with our heritage team and sometimes conservators to design what is almost always an alternate solution.”
For example, a project that involved retrofitting LED lighting into chandeliers that had been installed in 1927 had to consider heat factors because of the age of the plaster around the lights.
Heat sinks had to be mounted in various locations, adding time and cost to what is usually considered a relatively simple and straightforward job.
The Heritage Management Plan guides decision making on a daily basis in every individual part of the building. An action committee reviews, discusses and amends projects that are beneath a significant impact threshold.
The committee’s role can include referring projects to the Department of Climate Change, Energy the Environment and Water, seeking public consultation. This all takes time.
“The South East Wing, when it was refurbished back in 2008, involved a full referral to the department,” Grebert said.
“It [takes] approximately a year to do that full referral, and all the spaces required a heritage impact assessment. Then, guidance is developed around how to actually do the work.
“Finally, it goes to tender, with contractors needing to follow unique guidelines. Pieces might have to be retained, taken off safely, documented, then put back on. Then a conservator must do the conservation work to bring it back as close as possible to original.”
The other guide for engineers and construction professionals is the Burra Charter, published by Australia’s International Council on Monuments and Sites. The charter promotes a cautious approach to change.
“Our job is to do as much as necessary to care for the place by doing as little as possible,” Grebert said.
“That’s why I describe a lot of the work as ‘alternative solutions’. We have lot of non-compliance due to the age of the building. Sometimes there just isn’t much we can do to fully achieve compliance with the restrictions we have.”
When the exhibition spaces for the Museum of Australian Democracy were being planned, it quickly became clear that Old Parliament House was not intended as an exhibition space.
Unlike galleries, theatres and other arts complexes — which often have flexible spaces designed around the high likelihood of changing demands on those spaces — the building was designed with a very different purpose in mind.
For a recent Museum of Australian Democracy exhibition, for example, the challenge became how to build a space within a space: a box within a box.
What was originally the Opposition Party Room now had to contain a fully supported metal structure with a false floor that protected the original timber floor.
Engineers were contracted to design the structure, including the articulation through the false floor of all power and other services required to run the exhibition. Vitally, the work had to be fully reversible.
“That’s one of the real challenges,” Grebert said.
“After this exhibition is finished, all of it must be able to be deconstructed so the room can go back to being the Opposition Party Room again, with its leather lounges and the bookshelves and so forth.”
The house wins
One of Australia’s most culturally significant buildings, the Sydney Opera House, regularly tosses up challenges for engineers.
Historically, and up to the present day, many of those engineers have come from Arup, whose founder, Ove Arup, was heavily involved in the design of the UNESCO-listed building.
One of those Arup engineers is Alistair Morrison CPEng, Principal, Australasian Fire Engineering Lead, and relationship manager between Arup and the Sydney Opera House.
“With significant landmark buildings like the Opera House and the Australian Museum, they have differing needs that change over time,” Morrison said.
“Our role as consultants is to understand the problems they’re facing by inquiring about the issues they’re experiencing and listening to what their needs are and outcomes they’re looking for.
“Arup is a big organisation that doesn’t just do traditional engineering advice. We do all types of consultancy and advisory services. So we are able to connect our organisation, or the right people within our organisation, to solve those problems.”
Challenges within significant architectural buildings are constant, Morrison explains — not just because of varying internal needs but also, because those buildings must continue to perform in a dramatically changing environment.
The uses of the building and how it functions are often influenced by issues completely outside the control of its managers.
“There’s continual pressure, particularly on performing arts venues – whether it’s the Opera House or the Walsh Bay Arts Precinct,” Morrison said.
“You have a changing audience expectation in the performing arts, as the interpretation of the world around us continually changes. That adds increasing demand on the buildings to adapt to the changing artists’ needs. These days, flexibility is key.”
One such example of improved flexibility at the Sydney Opera House was the Concert Hall renewal project. The project consisted of a complex upgrade of cutting-edge staging and theatre systems, enhanced acoustics and improved access for people with mobility needs.
“One of the features of the Concert Hall renewals were upgrades to the winching systems and motors,” Morrison said.
“There was significant increase in loads that needed to be accommodated within the existing structure. The lead structural engineers Xavier Nuttall enabled a fourfold increase in the capacity of the ceiling structure for the motors and equipment.”
“These were substantial upgrades that had structural implications, spatial constraints and a number of changes to the design of the theatre,” Morrison said.
“It all meant we had to re-evaluate the safety and fire strategy.”
Another recent project involved the transformation of the business offices on the north-west of the building to what is now called the Centre for Creativity.
What was once a relatively bland office space is now adapted for flexible multimedia and educational experiences.
“Those innocuous sorts of changes can be quite an engineering challenge, particularly with structures where we’ve had to look at the impact on load paths as a result of opening up the space,” Morrison said.
“We looked at how changes integrate with the existing exit paths within the building to ensure safety is maintained and minimise changes required outside the project scope.”