How to enjoy mass timber and CLT –  a new-found love these young builders want to share

Brother Nature, a young brother and sister-led building company based near the New South Wales snowfields wants other Australian builders to share the enormous benefits they discovered when they became enamored of mass timber. They’ve even provided a handy check list of how to get going.

Annalise Knight and her builder brother Andy started Brother Nature as a residential construction company around 10 years ago. They grew up with strong roots in family building – their dad was an electrician and handyman who raised five kids with a one-man business. He owner-built their home in Cooma, NSW, with the help of a few uncles.

“As adults we started to work out that houses that weren’t built by our old man didn’t really operate very well,” Knight says. 

During their first few years in the building business the pair saw many things that needed changing. Over time they developed Brother Nature’s mission of using intelligent and sustainable design and construction techniques to improve the standard of Australian homes and reduce the industry’s environmental footprint. Big goals for a relatively small family-owned company. “And along that yellow brick road, we discovered mass timber,” she says.

Their work in the Snowy Mountains region, ranging from private homes to multi-residential projects that fit into the NCC’s Class 2 building classification, which is anything “where people live above and below each other.” This can include apartments, townhouses, duplexes and even single storey homes with a common basement. The company has also more recently started doing small-scale commercial projects such as a Caruthers Chalet at the Perisher Ski Resort.

The Brother Nature office has grown to a team of five as well as a couple of permanent site teams, with Knight as the general manager. But they also work with an extended group of architects, draftspeople, structural engineers, interior designers and Passive House experts on a project basis as needed.

Working with mass timber

Brother Nature is currently working on several medium-scale mass timber projects. These include the Perisher chalet, a 24-bed ski lodge which will be Australia’s highest altitude mass timber building, and the Lakeside complex of 35 townhouses in Jindabyne, which will incorporate both mass timber and off-site construction.

The siblings and their team initially didn’t know too much about timber construction. But there was a phase about two years into their business when Andy and one of their more curious draftsperson spent a lot of time investigating this material and becoming familiar with it.

The result was their decision to start using Cross Laminated Timber (CLT), a panel product often known as “jumbo plywood” that combines the lightweight and sustainability benefits of wood that rivals the strength of a precast concrete panel.

What is mass timber and Cross Laminated Timber (CLT)?

Mass timber is a category of engineered timber products used in construction. Unlike conventional timber, mass timber products are made by bonding layers of wood together, producing panels and beams that are exceptionally strong, durable and fire resistant. Products in this category include CLT, glulam (glued laminated timber), and others such as dowel-laminated timber (DLT) and nail-laminated timber (NLT).

In CLT, layers of timber are glued together with the grain of each layer alternating at 90-degree angles. This produces an extraordinarily strong product that can be used to build walls, ceilings and floors. CLT is one of the products that’s opened up the possibility of constructing whole buildings entirely from timber.

If you need a visual explanation of how CLT is made, see the little animation on XLAM’s website (one of Australia’s main CLT suppliers).

The benefits of CLT

In Australia and New Zealand CLT is largely manufactured from locally grown pine. It has a raft of sustainability and other benefits, many of which are shared by other mass timber products, including:

• The absorption of carbon dioxide from the air by pine (or other tree) plantations, which take about 30 years to mature.
• Captured carbon from the atmosphere, which makes up half the dry weight of timber.
• Timber has far lower embodied carbon than comparable construction materials such as concrete and steel, meaning less emissions from its manufacture, transport and storage.
• As a lighter building material CLT requires smaller foundations, meaning less use of steel and concrete.
• CLT is amenable to offsite construction, which creates efficiencies in the use of materials and less construction waste.
• Cost benefits: Although mass timber materials are more expensive, factors like smaller foundations, offsite construction, faster building timeframes and reduced labour costs for lightweight materials can produce overall savings.
• The health benefits of living and working in timber buildings, such as reduced blood pressure, lower stress, improvements in emotional state and healthier indoor air quality.
• Alignment with personal and social values of investors and other stakeholders, which may include sustainability and building healthy communities.
• High performance and quality standards in mass timber buildings may increase the value of these structures in the future, when compared to low cost and less sustainable building practices.

According to Knight, one of the most difficult parts of mass timber and CLT construction, is not fire safety but moisture management.

CLT is designed to accommodate substantial fire resistance, and unlike steel remains structurally stable in extremely high temperatures. For high-risk situations it can also be covered with a fire resistant coating.

Moisture management, on the other hand, remains a hot topic of debate in the mass timber industry. This includes making sure timber is completely dry for construction, and managing moisture and condensation once buildings are operational.

There are numerous products and systems on the market, but the issue of ventilation and its impacts on energy efficiency are still under discussion. “Nobody wants $50 notes flying out the cracks in their windows,” she says.

Brother Nature’s recommendations for others interested in this space

Knight says that there are few Australian building companies interested in mass timber and CLT construction in the mid-rise space. Apart from some beautiful single homes and the occasional sexy project like Atlassian’s Sydney headquarters, a 39-storey mass timber hybrid tower, there hasn’t been much action in this space.

Knight is all about encouraging others to venture forth in CLT construction. “A major challenge for me now is trying to grow the category, as people don’t know what mass timber is. Our vision is that if we, the little guy, can build these better buildings, then the bigger guys are going to have to catch on, because ultimately, we should all be able to experience better buildings.”

If bigger builders get involved in CLT and mass timber, this could lead to an increase in demand and domino into relevant changes to the NCC. These developments could then facilitate the bigger role that mass timber has the potential to play in the Australian construction industry’s journey to net zero. 

Knight’s recommendations for other construction players, both big and small, who are considering entering this space include:

• Get help from experienced Australian suppliers such as XLAM and Timberlink, who are doing a great job of shepherding industry through the CLT process
• Consider overseas suppliers such as Austria’s Binderholz, which may be surprisingly cost effective for specific projects/contexts
• Get advice from overseas partners, many of who see Australia as a fantastic market and are happy to share their skills. They’re only a Zoom call away
• Work with experienced professionals from the start and get the design right for mass timber at the start because flipping a project from concrete and steel to timber or figuring things out on site can be very expensive
• Make sure you have the right people on board from the start – from engineers to architects, builders and tradespeople
• Do your research – know as much as you can and keep learning along the way!

Can mass timber help solve the housing crisis?

Given that some people say mass timber buildings cost more than conventional buildings, there’s a perception that the product verges on the luxury end. But Knight insists that this is not the case.

It’s almost impossible to compare, she says – mass timber and regular house construction are two separate products. Mass time saves times. Much of the design work is done way before the materials come to site and they are well designed and cut to size, so builders are not forced to essentially design on the hop to make things work.

Then there is the finished building itself. It’s low cost to operate – with heating or cooling bills slashed. And there’s better health outcomes which is a boon to the social, community and affordable housing markets.

Knight would love to work in that market.  “If we can find a way to deliver there, I think we’ll really start to have a huge impact on the lives of ordinary Australians.”

Future directions for Brother Nature

Knight says the Australian CLT industry is doing well. “But when you start to look at the projects overseas, you realise there’s still much to learn. The industry is maturing, and I personally think it’s ready for the number of buildings that Australia needs to deliver over the next 10-15 years.”

And she’s had no problem sourcing the material much of which is imported. There’s a couple of containers making their way to an Australian port with the company’s name on the label, she’s excited to share.

In the immediate future, Knight would like to see Brother Nature help to build bigger and better communities, especially in regional NSW. And she’d love the company to help out in bringing mass timber and CLT to the table in the nation’s housing crisis.

She plans to continue being a part of the mass timber community, and to help it keep pushing the industry forward. Big goals, but the Knight siblings and Brother Nature have never shied away from these.

“I think we’re ready to take it on,” she says.