Factors influencing the adoption of mass timber in the South African construction industry: A UTAUT-based approach

The global construction industry is under pressure to reduce its carbon emissions, and mass timber has emerged as a promising alternative to conventional building materials such as concrete and steel. While hundreds of multi-storey timber buildings have been constructed worldwide, there is limited evidence of corresponding growth in Africa. This study investigates the factors influencing design professionals' behavioural intention to adopt mass timber in the South African construction industry. A conceptual model was developed by extending the Unified Theory of Acceptance and Use of Technology (UTAUT) with three context-specific constructs: perceived environmental motivation, personal resistance, and perceived cost. Data were collected from 92 architects and structural engineers through a structured survey and analysed using Partial Least Squares Structural Equation Modelling (PLS-SEM). Iterative measurement model assessment led to the removal of social influence due to indicator reliability and discriminant validity failures, the merger of effort expectancy and facilitating conditions into a single construct termed execution capability, and the reduction of the instrument from 43 to 33 indicators. The final structural model explained 66.2% of the variance in behavioural intention and demonstrated high out-of-sample predictive power. Three predictors were statistically significant: perceived environmental motivation was the strongest predictor, followed by execution capability and performance expectancy. Personal resistance and perceived cost were not significant. The findings suggest that environmental credentials, rather than technical performance or cost, are the primary driver of intention to adopt mass timber among South African design professionals, and that professionals do not distinguish between the ease of using mass timber and the infrastructural conditions enabling its use. The study contributes to the limited empirical literature on mass timber adoption in Africa and demonstrates the need for context-specific modifications when applying UTAUT to construction material adoption.