A large volume of huge and complex buildings are being constructed in many cities, especially in the Far East Asia, The conventional regulatory control of building design on the basis of prescriptive building and fire safety codes and regulations may not facilitate the building designers to compile an innovative design. In particular, fire safety codes and regulations are noted to be rigid and have significant influence on the design of building layout and structures. The introduction of a performance-based approach, in which buildings are designed to meet the performance requirements rather than strictly complying with the prescribed rules, recently provides the opportunity for building designers to generate unique and daring solutions. To examine the effect of introducing such performance approach in the regulatory system, a conceptual system dynamic model has been established, with reference to the Hong Kong building control system, to explore the behavior and changes of the system. The model is conceptualized around the technical and mental factors that impact on the decisions of building control officials and various issues. To build the system dynamics model, a causal diagram showing the interrelationships of the system components is first established. It can assist the identification of attributes that affect the implementation and the performance of building design control policy. On the basis of the causal diagram, a simulation model is formulated. Some issues that may affect the implementation of performance-based fire safety design can be examined and discussed.