This research aims to define an approach to identify construction-related design information at early design stages. Those information can be extracted from a building information model and used to support an automated, rule-based constructability checking in a proactive manner. Focusing on formwork construction of cast-in-place concrete building structures, this paper uses a case study and applies the object-oriented paradigm inherent in a BIM model as the opportunity and mechanism for leveraging constructability reasoning that is captured from the structural design process and construction expert's knowledge. The hierarchical model of product information for the case study building is presented and then aligned with the formwork decision-making for product realization. The accessibility of the construction-related design information, in terms of level of definition as well as representation within in the design model, is discussed, indicating the needs for system information progression since early design stages to support the BIM-enabled, automated review.