Timber! Five reasons to choose the good wood

27 Oct 2021

La Trobe University has turned to an ancient material to build a $100 million centrepiece for its new City of the Future.

One of Australia’s largest mass engineered timber projects, the new 624-bed North and South student accommodation buildings boast a 5 Star Green Star As Built rating and are aligned with the university’s net zero 2029 targets.

While La Trobe University has its sights set on the future, there was also an immediate goal to get the project up-and-running in just 24 months. With both speed and sustainability front-and-centre, timber was an obvious solution.

So, what did La Trobe University’s project team learn from choosing the good wood? We asked three dynamos at our recent Green Building Day.

1.     Timber supports the need for speed

One of the biggest challenges for the project team – which included Jackson Clements Burrows Architects, Multiplex and Stantec – was meeting a hard deadline. La Trobe wanted the building ready for the first semester of 2021. Mission completed!

“Speed of construction was critical to the project’s success,” JCB Architects’ Associate Danielle Pacella told our enthusiastic Green Building Day audience.

Timber can be grown, manufactured and cut to size offsite, making for quicker and more cost-effective construction. More than 4,500 cubic metres of mass timber panels, beams, columns and were used in construction of the La Trobe student buildings. “That is enough timber panels to cover the MCG Oval twice,” Danielle explained.

Builder Multiplex installed on average 30 to 40 panels a day, achieving 70 panels on one particularly fine day. Multiplex completed a full floor every nine days. A comparable non-timber project for Monash Clayton took 12 days per floor – “so it’s a significant program saving,” added Multiplex Senior Project Manager Danielle Savio.

Danielle Savio noted that design and procurement of a timber building is “heavy at the front end”. “But if you can get that right and get the timber to site, construction on site is relatively straightforward.”

2.     Timber pushes us towards net zero

La Trobe University has set a target of net zero for Scope 1 and Scope 2 carbon emissions by 2029 – but Scope 3 and embodied carbon are also on the university’s radar, said Marilyn Pisani, Stantec’s Sustainability Engineer. For this reason “it was really important to minimise embodied carbon on this new build,” Marilyn added.

Timber, when sourced from sustainable, fast-growing forests, acts as a carbon sink. Research has confirmed roughly one cubic metre of mass timber, like cross-laminated timber, sequesters a tonne of carbon. On the other hand, concrete and steel manufacture are responsible for around eight percent of global greenhouse gas emissions apiece.

Multiplex, along with Stantec, analysed the global warming potential of La Trobe’s project. Even when shipping (La Trobe’s Austrian Spruce was sourced from a sustainable timber supplier in Italy) and extra materials are considered, choosing timber delivered an almost 76% reduction in carbon when compared with business-as-usual. The 7.5 million kilograms of carbon equivalent saved is equivalent to “taking 1,600 cars from the road for a year,” said Multiplex’s Danielle Savio.

3.     Timber is a no-waste wonder

In conventional construction, materials are ordered in mass quantities, cut to size on site, and assembled. On the other hand, the bulk of mass timber buildings are manufactured on the factory floor, using computer-guided fabrication precision. This made-to-measure approach virtually eliminates waste.

Danielle Savio told our Green Building Day audience that Multiplex is “spending a lot less on bins and waste removal from site with a mass timber structure”.

There’s another side to the waste story. Designed like a giant Jenga set that was easy to install, the North and South Apartments can be easily disassembled and reused on future buildings if La Trobe University’s plans change.

4.     Timber is safer, cleaner and quieter

Because timber is around 30 per cent lighter than concrete or steel, it is easy to handle and assemble. Construction workers spend less time on site (and less time at heights) with one US estimate suggesting that mass timber buildings are “roughly 25% faster to construct than concrete buildings and require 90% less construction traffic”. Forget the noisy neighbours when timber is in town!

Danielle Savio noted that La Trobe University’s site was “cleaner and safer” not only because there were fewer injuries. In industry where silicosis is a serious safety hazard, reducing concrete dust and concrete cutting on site creates a safer work environment.

5.     Timber is nature’s fingerprint

Then there is timber’s enduring appeal as natural and healthy material. Research from Planet Ark has found that timber interiors can boost occupants’ emotional state, reduce blood pressure, heart rate and stress levels.

At La Trobe’s North and South buildings, the interior timber features are exposed to make the most of these benefits. Danielle Pacella said the interior was appreciated by students and echoed the natural bushland setting beyond.

Danielle Savio agreed. “Timber is biophilic,” she said. This makes it “warm and inviting”.

The project team did note several challenges, and smoothing out supply chains and capacity building in the industry were chief among them. But they urged the industry start gearing up for a timber transformation. “We often explore the benefits of timber during early project stages with our clients – and they are keen to get on board,” Danielle Pacella said.

But what do the students say? While its early days for La Trobe’s new digs, we know 91% of students around the world want their places of study to take sustainability seriously. La Trobe’s new student accommodation sends that message out loud and clear.