The architecture, engineering, and construction (AEC) industry is well known for low productivity, with a critical obstacle being the difficulties associated with understanding the mechanism of job performance. This due to established theories being incapable of capturing and dealing with the complexities associated with construction projects, with extant performance studies falling short in the context of complex projects by not grounding the factors involved in a common conceptual model that articulates the mechanics of job performance. In response, this study builds on person-environment (P-E) fit theory using a stimulus-organism-response paradigm, to develop a foundational conceptual model of the performance-related working behaviors of construction professionals. This study emphasizes the mediating role of P-E fit assessment and integrates key P-E relationships in a simplified framework, with a common layer based on P-E fit assessment factors that both accommodates previous studies and lays a coherent foundation for future studies. The model can also be applied in a reverse, diagnostic, capacity to identify corrective approaches and appropriate management strategies, and is easily adaptable to more general situations beyond the construction industry. Concluding remarks concern the major contributions made and prospects for future development.