The factors impacting the adoption of industrialised building systems (IBS) technology is gaining increasing attention in Malaysia, particularly because of the slower-than-expected pace of adoption. This paper aims to identify the factors that influence the decision to use IBS in construction projects. The research methodology is embedded in an interpretative phenomenological paradigm that is applied through semi-structured face-to-face interviews with a group of 27 experienced construction stakeholders from across the industry. The ‘inter-project perspective’ is contextualised through an interpretative content analysis that synthesises varied accounts of interviewees to identify the influence of different factors on IBS adoption. The findings group the factors that influence IBS adoption decisions into ‘structural’, ‘contextual’ and ‘behavioural’ themes. The ‘structural’ and ‘contextual’ themes have five factors impacting the IBS decision, whereas ‘behavioural’ has four factors. The 14 factors are project condition, procurement setup, management approach, communication process, decision-making style, economics conditions, technology development, government involvement, sustainability feature, stakeholders’ participation, experience, bounded rationality, awareness and attitude. These factors are influenced by 49 ‘aspects’. It is suggested that the IBS adoption decision is complex and influenced by many interconnected ‘aspects’, beyond government incentives, cost, attitudes and skills. Moreover, a more integrative approach that considers all factors is needed to make the IBS adoption decision. However, because the intensity of influence of these factors/aspects may differ country to country, as may the nature of the construction industry, any attempt to develop a strategy or policy to increase IBS adoption or integration needs to be targeted.