Multizone airflow analysis is an important tool for analyzing the performance of a building from the perspective of ventilation, contaminant transport, and indoor air quality. However, many airflow modeling and simulation applications such as CONTAM do not allow for easy input of previously developed model contents, which hinders their effectiveness. Consequently, in the current practice engineers commonly need to rebuild a multizone model of the target building, although the majority of the required information has been already produced and available. This is time consuming and may result in differences between the original model and the analysis model. In order to successfully implement the integrated building design process using a Building Information Model (BIM) to address the deficiencies, this paper presents processes to illustrate detailed workflows along with key decision making points, and exchange requirements identified within the processes. This efforts facilitates the implementation of BIM into an integrated building design process by contributing to the automation of information extraction from the BIM model and generation of its airflow analysis model.