AbstractCritical decisions about whether and how to integrate sustainability measures into the life cycle activities of green buildings are made in the early architectural design phase. To this end, researchers have advocated the use of various green building simulation technologies (GBSTs) to perform sustainability analyses to support integrated architectural design processes, cross-disciplinary communications, and evidence-based decision making. However, the adoption of GBSTs in architectural design practices remains limited. Building on the technology acceptance model, this paper investigates the determinants and mechanisms that influence the adoption of GBSTs in practice. Empirical data collected from architectural designers in Taiwan through qualitative interviews and a quantitative survey show that perceived usefulness is a strong predictor of designers’ intentions to adopt GBSTs. Job relevance, result demonstrability, compatibility, and competitive advantage are also important determinants of GBST adoption. Practical recommendations are offered to encourage greater adoption of GBSTs in architectural design practices. Theoretically, this research extends the technology adoption literature in the architecture, engineering, and construction (AEC) industry by broadening and deepening the understanding of context-specific determinants of GBST adoption.