CLT vs lightweight timber frames – Friends or foes?

By Margules Groome

Is the market for mass timber building products expanding? Will it be a lengthy process or it will happen quickly?

The days when CLT was seen as a “hobby” in Australia, or more exactly as “an interesting trial”, have passed. Currently there is hardly a day goes by without a new CLT or glulam development announced in the media. Some reports praise the green credentials of these mass timber building products; others underline the innovative aspects of the products in building developments; and yet others acknowledge efficiency savings and improved workplace safety during construction aspects.

CLT has been developed over the last 20 years and is well recognised abroad (Fig. 1). In Europe, more than 70 per cent of the CLT production is used for townhouse construction. In Australia, CLT has only recently started to become part of the Australian construction and forest industries. The introduction was achieved through the development of several few large apartment complexes with CLT incorporated in the designs. This soon led to the establishment of a domestic CLT manufacturing plant, XLAM Australia, and an increasing use of CLT in a range of building projects including office blocks, childcare and kindergarten centres and houses.

Fig. 1: CLT global historical & capacity development. Source: UNECE 2015, Margules Groome, Brandner 2012, Graz University of Technology

The National Construction Code 2016 (NCC) provides an array of opportunities for CLT and glulam by now permitting the construction of taller wood buildings. The lightweight timber framing sector, which continues to be the largest part of timber building components in Australia, can also benefit from the improvements in the NCC.

A question often raised is whether CLT prefabricated panels will take market share from the lightweight timber frames and their associated prefabricated systems. Will CLT slowly decimate the sawn wood market taking-out volumes which are normally destined for timber framing?

Fig. 2: Main AU SWD sawnwood production capacities (% of the total installed capacity) & XLAM Australia location

Margules Groome’s view is that the two prefabricated systems have their own individual market segments each with a positive market outlook. In addition, the timber grade used for CLT production is different compared to what lightweight timber framing requires. This means that the two systems do not compete for raw material, ameliorating concerns about potential competition. On the contrary, softwood sawmills now have an opportunity for better utilisation of their lower grades pine timber – in CLT manufacturing.

All major softwood (SWD) players in the timber processing industry (fig. 2) are well-positioned (location / capacity-wise) to take advantage of the new mid-rise building opportunity and the demand for “faster to build” and “greener” buildings. Currently there are a few leaders in the mass timber building products manufacturing in Australia except for Hyne’s investment in CLT and advanced manufacturing of glulam. Many others are still to follow.

Construction of the Library at The Dock, Melbourne

A log and sawnwood supply, substitution and trade analysis, complemented by a cost competitiveness analysis can provide the necessary answers to those contemplating joining the trend to CLT.