Timber buildings are environmentally friendly, the way of the future

This is a big shift from 30 to 40 years ago, when most of the timber being harvested was from native forests. Professor Rodney Keenan, chair of forest and ecosystem science at the University of Melbourne, said the shift towards plantation timber was partly driven by a controversial scheme set up by the Howard government granting hefty tax deductions to businesses that invested in timber plantations to bolster local production . It resulted in some native forest clearing rather than farmland being bought for growing.

A rise in environmental concerns led federal and state governments to agree in the 1990s to stop converting native forest to commercial plantations and to implement sustainable native forest management practices.

Today, plantations are usually located where land was cleared decades ago. As Blanch explains, these are where trees of the same species are grown specifically for harvesting decades later, for example radiata pine or Tasmanian bluegum, and they’re planted in rows all at once, so they are the same age with machines able to travel between. If wildlife gets into it, the timber company must take steps to protect the animals.

How do we know if the timber being used is sustainable?

Trees and forests evoke a lot of emotions. So, sometimes, do plantations: “When people see trees cut down they think they’re destroyed and in some ways that’s what’s happened to the individual tree that’s felled, but forestry is about making sure areas are regenerated,” says Keenan.

“We need to have a much more nuanced discussion about this, rather than simply ‘cutting down trees is bad’.”

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David Rowlinson, manager for Planet Ark’s Make It Wood campaign, says the Australian forestry sector is one of the most highly regulated in the world, and more than 95 per cent of Australian plantations and state forests are certified.

Forest certification has developed as a way of demonstrating the implementation of sustainable forest management practices, Rowlinson explains. To have a native or plantation forest certified as sustainably managed, an audit is undertaken by an independent, third-party certification body.

The two major global forest certification bodies are the Program for the Endorsement of Forest Certification (PEFC) – known as Responsible Wood in Australia – and the Forest Stewardship Council (FSC).

Wood sourced from certified forests are tracked through the supply chain using chain-of-custody certification and consumer products are then labeled with a certificate number.

“Look for and use certified timber,” says Rowlinson. “Certification ensures that wood comes from legally harvested and well-managed forests and plantations. Most importantly, this also ensures that when a tree is harvested another is planted in its place, thereby maintaining the carbon cycle.” In other words, the job that trees do pulling carbon out of the atmosphere continues.

An artist's impression of Hines' timber office tower in Collingwood, due for completion mid-to-late 2023.

An artist’s impression of Hines’ timber office tower in Collingwood, due for completion mid-to-late 2023.Credit:

While both systems are robust, the FSC certification is viewed as more stringent and native forest operators may not get endorsed. Keenan says that’s because FSC relies heavily on consultation with environmental groups which often do not accept that sustainable harvesting of native forest is possible.

There are other disagreements within the industry. The use of fire-salvaged trees – going into designated areas to harvest trees that have been killed by fire – is highly contentious, for example.

Rowlinson supports fire-salvaged wood activities in some circumstances. But others argue that it damages surviving plants, animals and forest conditions, such as soil, that are more vulnerable after fire, Keenan explains. Blanch says the continued use of fire-salvaged trees is detracting from where the focus needs to be, which is expanding plantations.

“It’s seen as a last desperate grasp to hold on to native forest logging when we should be getting into plantation.”

What’s the future for native forestry?

Native forests – such as at Victoria’s Wombat State Forest or at Warburton’s Big Pats Creek – are where battles are fought between the foresting industry and conservation activists.

Blanch says Australia’s forest has been relied on for too long for competing purposes: on the one hand, to support wildlife and biodiversity, deliver our water and act as a holiday destination; on the other, to provide our timber.

This will gradually come to a close with the Victorian government committed to ending native forest logging by 2030, following a West Australian ban starting in 2024.

But there is disagreement over just how much native forestry should be occurring.

Rowlinson doesn’t believe it should be reduced, saying there is “no verifiable evidence that it will be at all beneficial from an environmental perspective”.

It’s currently only legal to harvest trees in about 3.7 per cent of native forest, he says, with “virtually no harvesting of old-growth forest”, and the sector centers on high-value species – including Tasmanian oak, blackbutt and spotted gum – which cannot be grown in monoculture plantation and have architectural or furniture-based uses.

Blanch, however, says that the WWF wants a near-100 per cent plantation-based sovereign timber industry that is certified as sustainably managed to the highest standards. He says there are some instances in which the organization would support native forest logging, for example when it is very small scale.

“We’re not against all native forest logging. We’re against industrial scale that has significant impacts on the environment, carbon and water catchments,” says Blanch.

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Keenan believes we should be harvesting native forest at a “slightly lower level” than we are now, but using different methods that he deems more sustainable and can improve habitat outcomes, for example by felling small trees instead of very large ones.

“Australian eucalypt forests are resilient and they have wood qualities that are hard to replicate in plantation,” says Keenan.

He explains that forests that have regrown after being heavily burnt in the past or cleared for agriculture are often densely stocked with competing trees. This can make for a poor wildlife habitat and a forest that is under high stress, with low resilience to future fires.

“By thinning out those forests and using the thinned timber, we can improve the health of the forest and the condition of the forest for wildlife,” he says.

Is timber much more sustainable as a building material?

There is a growing push to grow Australia’s timber construction movement to reduce the industry’s massive environmental footprint, and a suite of recent development projects signal the country is catching onto a trend well-established in the United States and Europe.

The federal government announced this year that its Clean Energy Finance Corporation would invest $300 million in a new timber building program to support the use of wood to construct apartment and office buildings, with the technology proven to meet fire safety requirements.

A report from the government body found the use of mass timber reduced the embodied carbon of buildings – the greenhouse gas emissions associated with construction – by up to 75 per cent compared to steel and concrete.

Blanch disputes this figure but says it is “absolutely” true that mass timber buildings have a lower carbon footprint than steel and concrete structures.

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“When trees grow, they soak up carbon, and about half the weight of a tree is carbon. It’s a very, very good head start compared to digging up and smelting steel and producing concrete,” he says. “If that wood is stored in a building for 50, 100 years and then recycled at the end of its life cycle, that is a much better carbon outcome.”

Rowlinson says wood is the only major building material that is a renewable resource, and the carbon in timber will be stored for as long as the building exists.

“An average Australian house will use about 12 cubic metres of radiata pine in its structure. This will be regrown in Australian plantations in less than two and half minutes,” he says.

Blanch also hopes the timber push will encourage the development of low or zero carbon steel and concrete. The WWF runs the Materials and Embodied Carbon Leaders’ Alliance, which supports all sectors of construction to set and meet climate targets.

Do we have enough timber?

With a third of the timber used in Australia coming from imports, one of the biggest challenges is the country’s shortage of commercial plantations. Nationally, the plantation area for softwood (which grows for 20 to 30 years) has flat-lined in recent years, while hardwood (which grows for 50 to 60 years) has reduced.

“We don’t have enough wood. Our plantation area is not enough to meet domestic demand,” says Blanch. “We’ve got to get our native forest logging sector phased out in a fair and just transition, and actually expand the plantation estate.”

Rowlinson warns that leaning on imports can be risky.

“The diminishing local supply obtainable from our own forests has inevitably forced our demand for hardwood to be increasingly met by imported timbers, often derived from the tropical rainforests of Asia-Pacific nations,” he says.

“This is highly undesirable and … we need to be careful that seemingly well-intentioned ‘save-the-forests’ preservation agendas championed by environmental activism don’t result in adverse, unintended consequences.”

Forest cleared for an oil palm plantation in Indonesia in 2014.

Forest cleared for an oil palm plantation in Indonesia in 2014.Credit:Michael Bachelard

The Australian Forest Products Association has been campaigning for government support to expand domestic timber production, with an aim of planting a billion trees and increasing the country’s plantation area by about 20 per cent.

Blanch believes the government should be exploring options for a carbon and biodiversity credits model to encourage more producers to start plantations and move the sector further away from native forestry.

“It’s a slow-growing crop,” said Blanch. “If you grow a eucalypt tree for 50 years you should be able to make money from not just its use, but also the carbon stored in it and the biodiversity it supports in hat time.”

Keenan says another matter to address is that a lot of Australia’s wood is exported. He estimates that as much as two-thirds of the timber harvested each year in Australia is exported as semi-processed woodchips, round logs, paper and packaging products.

“There’s scope to enhance the use of plantation eucalypt for local building products,” he says.

Is timber a perfect solution?

When we talk about using mass timber in construction, a lot of the time these structures are hybrids, for example with concrete used at the building base or in the lift shaft.

The materials aren’t “mutually exclusive”, says Rowlinson. The aim is to reduce a building’s embodied carbon and bring mental heath benefits to the people who eventually use that structure through a “biophilic” connection to nature.

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“Ultimately it’s about using materials where they make sense, and giving due consideration to the range of materials available,” Rowlinson says.

No building material is a perfect solution, but timber has a lot working in its favour, Blanch says.

“It is four steps ahead of steel and concrete in that it already can be carbon positive for soaking up more carbon than it releases,” he says.

Keenan adds: “We live in a world where our consumption has some level of impact on other things so we have to work out how to survive in this environment.”

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