Expert building professional Theo Pasialis talks about his work to speed up Australian take-up of CLT construction.

Theo Pasialis is a man on a mission. Director Construction at Holz DC, he has spent the past year working with his team to have cross-laminated timber (CLT) included in the standards of statutory bodies across Australia.

“We’re working to have an open dialogue, focused on education, with industry bodies such as the Housing Industry Association, of which Holz DC is a proud member,” Pasialis says.

The company is taking the message of CLT to industry professionals and the general community, promoting their projects, holding meetings, even giving tours through projects under construction. If they seem a little evangelical, it’s with good reason: they have seen CLT’s ability to slash build times up to 20%, control budgets with savings around 15% and deliver precise, high-quality results.

Holz DC links with developers and builders with their range of independent CLT experts, sourced from a national pool of best-in-class, to deliver a seamless and efficient ‘one stop shop’ for CLT construction. They are currently working on over 200 CLT dwellings in New South Wales and Victoria.

The need for such a service became apparent when the directors saw the slow take-up of CLT in the industry. As Pasialis says, “More investment is needed in educating architects, engineers and other consultants to understand the benefits of CLT, and how to design accordingly. When the consultants understand the technology, they’ll be able to steer their clients to CLT as a viable solution.”


Holz DC is currently working with a number of forward-thinking builders, developers, engineers and architects on CLT projects and the results are speaking for themselves. A recent project in partnership with leading residential CLT construction company, Hyperbuild has seen Australia’s first triplex build from CLT in Shellharbour on the NSW South Coast.

“Each dwelling is approximately 200m2 over two storeys” says Pasialis. “In total, approximately 350 panels of CLT were used, a combined weight of approximately 80 tonnes. We are incredibly proud to say the total erection time was only 15 days. Other than the ground floor concrete slab, all the walls, floors and roofs are built from CLT panels.

“Externally, the CLT panels were clad. The roof was finished with Colourbond sheets installed over the CLT roof structure. Internally some surfaces were left exposed as a visual-grade finish to highlight the timber. The majority of this building had plasterboard either directly stuck or with furring channels to the CLT.”

There were more efficiencies of time built into the project than just the ease of installing panels and the ability to plan in more detail with prefabricated product. Pasialis says, “The advantage with CLT floors is that trades can get into the building and start to do rough-ins once the floor is in place. There is no need for back propping of floors which restricts access to trades in a traditional concrete floor.”

And when it comes to environmental impacts, this development represents a saving of approximately 250-300 tonnes of CO2 over traditional masonry/steel construction. Even though most CLT is still imported from Europe, Pasialis says, “the carbon cost of shipping is very small in comparison with the overall savings achieved via CLT construction. Broadly speaking, in terms of manufacturing and transporting CO2 emissions, one tonne of concrete = approximately 1 tonne of CO2 emissions. One tonne of CLT = approximately 100kg of CO2 emissions.” He notes that a CLT manufacturer has recently opened in NSW and so future savings may well be even greater.

The Holz DC team includes builders, developers, architects and engineers. “They have all been through our quality standards process and are specifically trained for CLT installation,” says Pasialis. “We’ve also developed a good relationship with logistics companies that undertake transportation of CLT panels to building sites swiftly and efficiently.”

Holz DC’s Director of Engineering Bernhard Waschl is frequently in Europe to explore new opportunities and developments in CLT, but Pasialis sees areas where they still need to target their work in Australia: “Changes to BCA to embrace massive timber as a building material are required and we have no doubt this will happen. Furthermore, education is paramount across all stakeholders in the industry.

“Holz DC is committed to playing a part in this process through our stakeholder engagement activities and connections with industry bodies. We want to help builders, developers, architects and engineers de-risk their projects by using CLT. It’s exciting to note that there are a number of builders across Australia producing large buildings using CLT already.”

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