“Timber is the new concrete. The vast potential and versatility of engineered timber holds the key to construction for the 21st century, just as the 18th century was about brick, the 19th steel, and the 20th was concrete.” Alex de Rijke of London-based architecture firm de Rijke Marsh Morgan Architects.
We have it on good authority that cross-laminated timber (CLT) will be a major player in sustainable mid-rise building construction in the future. However, how far into the future that is, and how widespread its effect on Australia’s built environment will be is still a little up in the air, and according to some is much in the hands of the developer.
CLT is used around the world as an alternative to concrete and steel for all or part of a building’s construction and we’ve seen it used in projects up to 10-storeys in height. It is basically formed as timber panels that are fabricated by bonding solid-sawn timber together in transverse and longitudinal layers with structural adhesives. They are said to provide strength and stiffness properties similar to reinforced concrete and, depending on timber species and method of assembly, have much lower embodied energy consumption than many other building processes, such as the production of steel and concrete.
But while the environmental performance and structural strength of CLT has been well known in Australia for years now, its uptake as a viable alternative to concrete and steel in mid-rise building construction hasn’t been so obvious.
In fact, since Australia’s first CLT building went up in 2012, promising a “new era in the future of sustainable development” in the process, less than a handful of projects using the material have been completed on our shores since.
Forte by Lend Lease
In January 2016, the Australian Building Codes Board (ABCB) announced changes to the National Construction Code (NCC) that will enable timber buildings up to 25 metres in height to be lodged with planning under deemed-to-satisfy provisions. The proponents of CLT construction rejoiced unanimously because the change ultimately takes away another barrier dissuading developers and consultants from using CLT.
Currently, timber building systems are restricted to three storeys under the NCC’s deemed-to-satisfy provisions, with taller buildings requiring an ‘alternative solution’ to be designed and documented to gain building compliance.
The code change, to be effect from 1 May, will bring Australia up to pace with much of the rest of the world in terms of regulation and, for some, is an obvious move away from outdated laws with origins as far back as the 1666 Great Fire of London.
However, it is only one step in the normalisation of Mass Timber Construction (MTC) in Australia and if timber really does “hold the key to construction for the 21st century”, as architect Alex de Rijke says, then there is still a lot Australia has to do in short space of time to position it as a viable alternative to concrete and steel construction this century.
DEVELOPMENTS FOR CLT
Designed by South Australian architects Proske, Verde Apartments at Kent Town Adelaide is a five-storey mixed use residential project which uses CLT for all the load bearing walls, floors and ceilings on the apartment levels, with conventional concrete and steel construction for the lower two levels.
Since migrating from England, Nick Hewson, Senior Structural Engineer at Aecom has become somewhat of a spokesperson for MTC in Australia, lecturing for universities, advising government and the ACBC, writing academic and news articles and consulting as an engineered timber expert for Aecom.
Upon hearing the news that the NCC was changing to encourage more tall timber buildings, Hewson notes that while he wasn’t surprised (he actually wrote a design guide for these type of buildings which was instrumental in the change happening) he was relieved, mostly because it will save his team a lot of time and effort in getting tall timber buildings over the line at planning stages.
“The previous alternative solutions route meant going through time-consuming and costly processes to demonstrate compliance such as consulting with fire brigades etc.” he explains.
“This code change has taken away that leg work and risk.”
But Hewson is more excited about a few other MTC developments in Australian, most notably some recent changes to the local supply chain of CLT products that could be the tipping point for widespread MTC uptake in Australia.
“The biggest shakeup in Australia has been the number of the suppliers of CLT and the increasingly sophisticated services they offer,” says Hewson.
“There are a lot more European CLT manufacturers with Australian representatives nowadays and they’re beginning to take our market a little more seriously.”
The suppliers Hewson talks about are also beginning to understand that Australian builders, designers and engineers who are considering CLT for their project want more than just sticks of timber—they need an integrated service that makes the transition from concrete/steel to CLT easier.
“A couple of years ago there were a lot of people who could deliver timber into the country but it wasn’t enough,” he explains.
“We needed a much more integrated solution to compete with concrete frame contractors—they needed to supply a full system, which includes things like engineering, design input, costing and installation.”
Rob De Brincat, Business Development Manager at XLam Australia, a subsidiary to XLam New Zealand who is the only manufacturer of cross laminated timber in the Southern Hemisphere, agrees with Hewson on this point.
“While we still consider ourselves suppliers, not contractors, we understand that we need to provide enormous amount of support in all of the consulting, design and certification services, as well as installation,” he explains.
“If we ignore that, the market won’t accept our system.”
For both De Brincat and Hewson, the sophistication of services from Australian CLT suppliers also comes in response to two of the major barriers still facing CLT and MTC in Australia, both of which are inexplicably linked. The first is that the Australian construction industry is inherently conservative and (mostly) unwilling to go beyond our traditional methods for construction; the second is that there is a crippling lack of information and hard data about the true cost benefits of CLT. Both agree that addressing the latter holds the key to increased uptake in CLT construction in Australia, and perhaps fortunately for them, this data and information is beginning to come in.
CLT SUPPLIERS WITH AUSTRALIAN REPRESENTATIVES
While there will always be a degree of intellectual property that CLT companies will want to keep close to their chest, there’s also a degree of information the market needs in order to evolve and develop into something that’s of reasonable substance.
Information on the performance of completed CLT-buildings in Australia is relatively scarce, however there are new industry studies coming to the fore that provide detailed analysis of its viability as an alternative to concrete and steel construction.
Mass timber construction as an alternative to concrete and steel in the Australia building industry: a PESTEL evaluation of the potential was released by Paul Kremer and Mark Symmons of Monash University in late 2015. As the name suggests, the report analyses the viability of timber as an alternative to concrete and steel in Australian construction using the PESTEL (Political, Economic, Social, Technological, Environmental and Legal) tool which is used in business management studies to assess the viability of technology from a business perspective.
A very basic summary of the Kremer and Symmons report is that there are many advantages on offer for Australian developers choosing CLT, including - against popular belief - financial savings. These savings come primarily from the reduction in on-site labour costs however there is also scope, due to CLT’s comparatively low embodied energy, to capitalise on government incentives to reduce carbon footprints. This could come from policy that rewards carbon sequestration or a reduction in emissions from a shift from the more carbon-intensive concrete and steel production, or if some MTC production can be derived from recycled timber.
More specifically on the case of financial savings, the most up to date study of MTC cost comparison comes from Forest & Wood Products Australia who released Final report for commercial building costing cases studies: traditional design versus timber project in December 2015, showing ‘realistic’ timber costing information for building professionals in the non-housing building sector.
It summarised an experiment that compared the cost of constructing four commercial buildings in both timber and traditional materials in Australia. The building types were a seven storey office building, an eight storey apartment building, a two storey aged care facility and a single storey industrial shed. In all cases constructing the building in timber had lower costs than for the competing non-timber solution.
CLT was only used on the 8-storey apartment building which, not coincidently, was designed by Nick Hewson as a representative of Aecom with help from Studio 505 architects and Taylor Thompson Whitting Consulting Engineers. And while the results show a modest saving of 2.2 per cent when using CLT over a traditional construction solution, Hewson notes these are still very conservative estimates.
“They’re talking about a relatively modest saving but when you actually look at the detail of it they’re still being very conservative and ignoring a few things, like that the building is lighter and has reduced foundations.”
“They take account of a small program savings but we now from Europe that you can knock a third off the construction time of a lot of these buildings and that’s worth a huge amount of money.
“We would estimate anywhere between 10-30 per cent cost savings on these medium-rise constructions, but you would need a builder that understands where these efficiencies and savings are.”
The CLT structure of Stadthaus apartments in Murray Grove London is currently the second tallest in the world. It was constructed in 27-days by four men, each working a three day week. The Waugh Thistleton Architects-designed apartments store 185,00kg of carbon and were all sold out within two hours of their launch. Image: Gawker Media
IT’S A CHICKEN-AND-EGG/WAIT-AND-SEE POSITION
Kremer and Symmons, Hewson and De Brincat all suggest that there is a stance of vigilance from the larger tier one developers against CLT in the Australian market at the moment who are either waiting for a competitor to begin using the material or for a change in the market’s awareness of CLT.
De Brincat believes this change could come from the collective sharing of performance data and information about completed CLT projects among suppliers.
“We’re starting to make some progress along these lines and we’re hoping to work with other CLT suppliers to get details into the Australian marketplace so that it can gain the confidence it needs to grow a bit quicker than it did in Europe.”
Hewson believes that uptake will quicken once more Australian projects are completed and developers/builders fully realise the benefits of CLT construction.
“It’s a chicken and egg thing,” he explains.
“Until you get people to work on these buildings and to understand the time savings and efficiencies it is very difficult to actually to get a builder to put a dollar figure against them.”
On that, De Brincat also agrees.
“A builder will do the calculations and it becomes clear that it’s much faster build with CLT and identify that there is $500,000 cost savings in their own internal labour on a project but they’ll only choose to put $250,000 in their costing model because they’ve never used it before.
“That’s a decision they make purely based on the risk profile they’re willing to take entering into this phase. It isn’t until that the builder actually does the project – touches it, feels it, understands it –that they’re going to be able to throw a proper figure at it.”
FROM THE [AUSTRALIAN] HORSE’S MOUTH
Ardea Oosthuizen of Ecobuild Design recently completed the first CLT House in Australia at Maianbar NSW (pictured above) on a modest budget and within an incredibly tight construction timeframe. Ninety-five per cent of the structure is CLT which was prefabricated offsite and erected in eight days.
Oosthuizen says that while CLT was cheaper than suspended concrete floors and solid brick walls it was a dearer option than conventional timber/steel frame or brick veneer construction.Oosthuizen says that he would “absolutely” use CLT again and that it “was a delight to design with” but did suggest that there are some challenges associated with designing with engineered timber.
First off, finding and selecting a CLT supplier was a challenge for Oosthuizen, who eventually went with Rob de Brincat (mentioned previously) from Tillings (now working with XLam) who on all accounts did an excellent job of sourcing the CLT from KLH, Austria, and arranging shop drawings, stuffing, shipping, customs, de-stuffing and delivery directly to site.
The next challenge came in the design phase where a heavy load of detailed shop drawings was needed for individual CLT panels to ensure everything was correct size when it arrived to site in containers– “I couldn’t just run down to Bunnings to get replacement panels,” as Oosthuizen explains.
The delivery phase went extremely smoothly, notes Oosthuizen, the only challenge here was factoring in the sequencing and numbering of panels to ensure delivered to site in the right order for immediate installation to optimise number of crane lifts required. At the final stage of the CLT experiment – the actual erecting of the frame—the only problem was teething one for the builders who had never built with CLT and didn’t initially know how to connect the CLT to the concrete and steel foundations. That was overcome however and the structure was completed in eight days.
The house was cladded in untreated Design’aClad cypress pine from Frencham Cypress in Melbourne and Colorbond steel on the southern facades. Painted fibre cement soffits to underside of slabs and roofs.
OTHER PROJECTS AND DEVELOPMENTS IN THE PIPELINE
Australia’s CLT building sector is extremely hush hush. Not only is the project data from completed Australian CLT buildings locked in a Lend Lease vault somewhere, but all information about future CLT projects is basically confidential. What De Brincat and Hewson could tell us however is that a project has just broken ground in NSW which will be the biggest CLT project in Australia. There are also very strong rumours that a CLT manufacturer will be setting up a plant in Australia in 2016.
WHERE TO NOW, FROM THE EXPERTS
At the conclusion of Paul Kremer and Mark Symmons’s PESTEL report, which we highly recommend you download, the duo made a list of recommendations designed for those looking to promote the uptake of CLT in Australia.
- Industry stakeholders can spearhead the promotion of MTC when tendering for government-funded projects citing the ‘timber first’ policy adopted by France, Canada and Japan as case studies, or road maps, driving the local market.
- Industry stakeholders can lead the charge in publicising the virtues of MTC through the marketing of research findings – such as the Dunn’s (2015) timber-concrete comparison paper – to the wider construction, architectural, property developer and engineering sector.
- Industry should back peakbodies and associations. This is an approach supported by the key findings in the Survey of International Tall Wood Building (Forestry Innovation Investment and Binational Softwood Lumber Council 2014) for the development of MTC in places, such as Europe, Canada, and the United States.
- Industry can collaborate to secure funding to pursue a full feasibility appraisal for the development of MTC plant in Australia. Anecdotally, making a case for the establishment for a MTC plant in Australia is not so much about the level of investment required in plant and equipment to establish a viable facility, but rather the relative proximity to plantation resource and the capacity utilisation given the demand for product.
- Industry stakeholders could support researchers in exploring the barriers to entry and formulate roadmaps aiding industry in the progression of MTC.
- Those considering supply agreements for the distribution of MTC in Australia should ensure negotiations include considerable collaborative components – inclusive of product and design training, shared intellectual property, support for local testing (fire and acoustic) of product, etc. – and cooperative project management to ensure the delivery of projects given the manufacturers considerable expertise.