buildings’ design and the impact of various design features on infill developments’ carbon footprints—as compared to other construction systems. In Australia we need to find ways to increase acceptance and build industry capacity for rapid uptake of CLT construction systems.
A fundamental question is the potential market penetration and architects’ and developers’ acceptance of urban infill using CLT construction. The analysed cases show that not only technological but also social innovation is needed to introduce CLT systems more widely to Australia.
Since the mid-1990s, CLT construction has been introduced in several European countries and also in Canada. In Canada, CLT was used as a demonstration in the iHouse constructed for the 2010 Winter Olympics and has successfully been used in hybrid structures such as in the Earth Sciences Building at the University of British Columbia. The recent CLT introduction in Canada indicates that ‘a market penetration rate of up to 15 per cent in 5 to 7 years is realistic’ .
In Europe, engineered timber has become a growing sector: a recent European industry report, summarized in an article in Holzkurier , describes the realities of the CLT trend by highlighting that the top 16 producers of CLT panel systems were operating at 120 per cent of capacity in 2009–10 and were projecting a 20 per cent growth in production in 2010–11. The article notes that total production volume of CLT panels reported for 2009 was 269,500 cubic meters. Projections for 2012 (including new producers and new plants in the Czech Republic, Italy and Austria) would exceed 520,000 cubic meters. While there is a CLT construction boom emerging in middle Europe, CLT is still not a fully accepted system in many of the Scandinavian countries, despite their abundance of forests. The research will need to explore the hindrances that are evident in the Nordic countries, where engineered timber still has a small share of the market.
Research has been conducted in the assumed barriers. Roos et al.  commented that architects are primarily responsible for producing a functional design that should also be aesthetically pleasing to the client. They saw developers, on the other hand, as risk-averse in their planned constructions, and they select materials in a cost-constrained context.
Discussions with architects and developers during the scoping study conducted by Lehmann and Hamilton revealed significant interest in the CLT product in Australia, where both architects and developers were keen to compare the designs of a CLT building with that using traditional concrete and steel construction system. The use of Building Information Modelling (BIM) and Precinct Information Modelling (PIM) software for design of buildings and neighbourhoods is becoming more widespread, and architects who were interested in CLT were also keen to work with structural engineers to increase their knowledge of alternative low-carbon construction systems. BIM is already changing the nature of the procurement and delivery process of buildings. It will be interesting to see how development of new modelling software will support this trend. Prefabrication, driven by the latest CAD-CAM technology, allows the production of complex projects with many different individual elements, each designated for a certain position in the building.
Architects and developers frequently raised concerns regarding durability and acoustics, for example in regard to the maintenance required to keep the timber looking ‘clean’. Sharing knowledge will be essential both through international research collaborations on CLT in Australia and by drawing on the European experience. Technical concerns include a focus on the structure and stability of CLT buildings, seismic design, durability design, adhesives, acoustics and vibrations, fire design and energy efficiency.
For industry acceptance of CLT construction, cultural, organizational and policy changes need to occur first, before new technologies can be introduced; including, for instance, policy changes (based on fire testing) to b