Scaling Up – The Maturation of Mass Timber

Designing and building with an environmental conscience is an increasingly urgent imperative. As a result, interest in green building materials is also rising. Within this conversation, mass timber is making noise; its structural properties and low carbon footprint making it a viable contender in offsetting and, in some cases, substituting concrete and steel.

Mass timber largely refers to wood products that are glued or nailed together in layers, resulting in exceptionally strong panels, posts and beams. As a renewable, eco-conscious resource with resounding structural capabilities and strong thermal performance, its benefits are compelling. The most used today include cross-laminated timber (CLT), where layers of wood are glued perpendicular to one other resulting in expansive panels with incredible strength; glue-laminated timber – or glulam – which involves laminates bonded and glued together following the direction of the grain, creating larger and longer members; and laminated veneer lumber (LVL), which uses small veneers and is thinner than glulam.

Andrew Maynard of Austin Maynard Architects is a big fan of CLT. “It’s super easy to use, it’s lightweight compared to concrete and it’s hard to argue with in terms of sustainability,” he says. Having used CLT extensively in the practice’s recently completed Union House in Brunswick, he’s well versed in the prospects of this material. “In terms of buildability, it’s incredibly strong – it’s essentially oversized plywood,” he says, referring to the alternating, layered grains that result in significant durability and strength. Mass timber’s ability to sequester carbon rather than emit it is also a huge drawcard. And as Andrew adds, its lightness results in less onerous delivery requirements compared to concrete, reducing the amount of carbon embedded in transport.

While indisputably desirable, two of the biggest hurdles we face in the maturation of mass timber relate to supply and industry education. “I don’t see many disadvantages, however, the catch at the moment is supply – it’s hard to get and consistent quality is a problem,” Andrew says. New materials often come with a lag in uptake due to the unknown. What’s more, using unexplored materials results in “danger money” inflating a project’s budget. Encouragingly, there is a growing pool of projects championing the use of mass timber on both a residential and commercial scale. Take The University of Tasmania’s West Park Campus in Burnie, where John Wardle Architects has utilised MASSLAM – Australian Sustainable Hardwoods’s (ASH) range of glue-laminated timber systems. Made from Australian timbers with some of the best strength-to-weight ratios available worldwide, MASSLAM allows for long spans, high ceilings, increased floor space or lesser beam depth. Drawing on biophilic design principles, this project is an exemplar for the elegant and informed use of mass timber. Even so, there are significant hesitations and misconceptions around mass timber’s suitability for projects of a commercial scale.

Elenberg Fraser is hoping to debunk some of these misapprehensions with its plans for an ambitious, carbon negative skyscraper in Perth, C6. The building has been designed by Fraser & Partners, a research-based design studio within Elenberg Fraser, created in response to the current climate crisis. Conceived as a hybrid building, the flooring systems, beams and columns are all constructed from CLT, glulam and LVL, with a significantly reduced amount of concrete forming the building’s core. As the project’s Principal Architect Reade Dixon says, C6 aims to illustrate the opportunities surrounding mass timber on a commercial scale while acknowledging the need for concrete in a 50-storey building. Associate Lucas Menegazzo echoes this, saying “we still need concrete in the core of the vertical structure due to the nature of these tall buildings, but the flooring and beam systems don’t actually need to be concrete from a structural point of view.” Demonstrating the incredible renewability of mass timber on a commercial scale, the project’s structural engineers say it’ll take less than an hour to regrow the 7,400 cubic metres of timber in the building. As Reade notes, “it’s an amazing natural resource that is really under-utilised.”

Elenberg Fraser and the project’s developer, Grange Development, hope C6 will act as an “agent of change” in an industry that’s well overdue in taking significant climate action. And this may in fact be possible thanks to the proposed open-source sharing of their research and design and construction documentation. Grange is harnessing transparency in its findings and methods, aiming to demonstrate what’s achievable with mass timber and encourage similar development. “There’s been confusion with CLT,” Lucas says. “People assume it can only be used in small residential projects, but the client was very interested in making this project a cost parity for others. It’ll hopefully serve as a proposition or a challenge for other partners in the industry to do better.”

There are increasing opportunities to explore and harness more sustainable approaches to design and construction, yet we rely heavily on key players – be that sole practitioners, boutique architectural practices or large-scale commercial developers – to adopt these materials and methods. Mass timber is one such opportunity, and pleasingly, it seems its uptake may in fact be on the rise.