Considered a landmark in the high-rise prefab space, the recently topped out La Trobe Tower development was initially conceived as a conventional build and transferred to a modular prefab solution due to the time, access and disruption constraints of its Melbourne CBD location.
It was ultimately delivered around 30 per cent faster than comparable projects, using Hickory Group’s innovative construction methodology and elements that included integrated structural prefabrication, a proprietary façade system and bathroom pods. John Lucchetti, Hydraulic and Fire Protection Section Manager at Wood and Grieve Engineers, cites the “key drivers” in pre-fab, which include the necessity to design up front and conceive each module as extensively as permissible prior to construction.
“This is necessitated by the repetition of each module as part of the building’s structure and also by the fact that, unlike a conventional build, these modules are being manufactured elsewhere at a factory.” “Another key factor in my experience is that you’ve got to have a very fine tuned understanding of how ‘complexing’ works; in other words, how each module interfaces and connects with other modules and with the building as a whole, which is different for every building.”
Pre-fab construction also requires a high level of clarity with contractors in terms of scope delineation. “You have to be very clear about which elements are going to be assembled on site and which are going to be essentially manufactured in a factory and how those elements slot together.”
This requires a radical re-think of the sequencing of the building and how and in what order the elements are conceived and installed. It’s perhaps no surprise that traditional working methods often need to be re-thought or overhauled, as Lucchetti, who is currently contributing to a group working on a new modular construction code of practice, confirms.
“Much of the traditional building code doesn’t cover many of the practices and approaches required by modular construction. Just as one example, you need to spend significant design hours working out the manufacture, transportation and logistics and lifting of modules.“
Lucchetti says he’s personally inspired by the pre-fab space. “My journey has spanned five or six years. I used to be in manufacturing, so a lot of the processes and systems involved make sense to me. It’s great to be able to apply lean manufacturing principles to building engineering, minimising waste and maximising efficiencies. We’re getting more and more enquiries about pre-fab or modular solutions from our clients.”
He adds that BIM software has proven a boon in modular construction. “BIM is great because of the fine grained level of precision it offers in terms of coordinating all the elements accurately. It allows you to convey a very clear picture to modular constructors of what’s required. The next evolution will be to use BIM at the manufacturing stage to create the key elements of the modules themselves. It’s already being used in some settings to set up dimensions and projections for jig-tools for example. I see an exciting future where BIM can be used for parametric modelling. So for example when you’re designing a module and something has to be altered dimensionally, BIM can be used to re-calibrate all the relevant dimensions across all modules.”
Given the recent success of the La Trobe Tower, Hickory Group is arguably leading innovation in the pre-fab high rise market with its solution, Hickory Building Systems (HBS). “Most of the prefab systems on the market are still geared towards housing our low-rise developments,” says Michael Argyrou, Hickory Group Managing Director.
“As high-rise builders in our conventional business, it made sense to bring our prefab capability in line with the rest of our business offering, so we began developing technology that would allow us to apply the same principles and benefits to larger, inner-city builds.”
“Hickory Building Systems’ key point of difference is that it’s not a one-size-fits all approach. We use interchangeable componentry that’s best for the project. That might involve bathroom pods, prefixed facades, precast slabs and structural steel frames, depending on the site and the construction approach.”
Another advantage of HBS is that it allows a more collaborative approach with architects and consultants in the planning stages, he says. “We can very quickly produce BIM models that show how the building will be broken up for manufacture, which helps resolve design issues, maps structure and consolidates spatials in order to achieve workable shop drawings and a bill of materials for manufacture.”
“We have also developed parametric, ‘smart’ BIM models that can be used by architects to map an entire building structure and facade for prefabrication using the Hickory Building System.”
Wind-loads and structural engineering considerations were a key focus in the development of the system and Hickory has an in-house structural engineering expert that works on all HBS projects.
Argyrou also notes that other large builders are using Hickory Group’s Sync modular bathrooms, to gain quality and time efficiencies on the fit out cycle.
“There is definitely opportunity to look at what other elements of the build can be taken off-site to streamline the build process. An example of that is our Sync bathroom business developing separate laundry pods, which we’ll be providing alongside bathrooms for a large-scale project in NSW.”
While an abiding perception remains that prefab is cheaper, Argyrou says this isn’t always the case. “[It] may be true with some low-spec modular systems, but these are often are quite limited in application. As our system is high-spec and high quality we find the cost to be comparable with conventional construction.”
“We find the real benefit to developers is the time saving; we can complete a high-rise project 30 – 50% faster, this could mean a 12 months faster ROI. As the quality is increased we also find there are fewer defect-rectification costs post completion.”
With the world’s cities continuing to grow and spiking land prices driving demand, in terms of offsite constructed high rises, Argyrou indicates the sky’s the limit.
“Our systems have no theoretical height limitations. We’ve just erected Australia’s tallest prefab building – a 44-storey tower, and are now working on another 60 level project in Melbourne. In fact building with this type of system is more beneficial in projects over 30 levels, so you can get the economies of scale in manufacturing.”
Belinda Smart, Built Offsite Magazine. October / November 2016. Read the full article online here.