Knock on (Engineered) Wood: Pathways to Increased Deployment of Cross-Laminated Timber

Abstract: Significant negative environmental impacts are attributed to the building sector. To complement operational building efficiency, mitigation strategies could further decrease these environmental impacts. One mitigation strategy is increased use of low-carbon and bio based building materials. The objective of this research is to support such sustainable transitions within the complex building sector of Sweden, via identification of barriers and drivers for a specific bio and low-carbon building material called cross-laminated timber (CLT). Results from literature review and questionnaire responses were used to form recommendations for increasing deployment of CLT in Sweden, via specific leverage points and instruments. Increased deployment of CLT in Sweden is also linked with several factors unique to Sweden. For example, environmental targets of the building sector, demand for housing, timber trends, development of a bio based and circular economy, and resource efficiency. To further validate and enhance results, global examples of successful CLT manufacturing practices, sustainable innovation transitions, and CLT support instruments were also examined. Results were also analysed using multilevel perspective, technology innovation system, and innovation diffusion frameworks. These tools were used to gain an interdisciplinary, comprehensive perspective and strengthen understanding of the building sector using systems thinking. Results showed main barriers as lack of knowledge or skills, negative perceptions, perceived costs or risks, misalignment with regulations, and technological path dependencies within the Swedish building sector. Main drivers were CLT’s carbon sequestration, low embodied carbon, renewability, efficient manufacturing and construction, cost competitiveness, and prefabrication. Key actors included building project owners, contractors, architects, engineers, the national housing authority (Boverket), and municipal building companies. Recommendations included education, skill building, green procurement, stronger materials focus in certifications, environmental evaluations of materials, environmental material requirements embedded in contracts and tenders, material carbon tax, stronger focus on building lifecycle impacts, and increased political focus on building materials. Recommendations are categorised and prioritised in the conclusion for clarity.