Decision making for rescue and evacuation is critical for disaster response operations not only in open spaces but also in buildings. For infrastructures with large and complex geometrical layouts, decision making could be facilitated with computer-aided approaches for better accuracy and efficiency. This paper aims to respond to fire in buildings. We combined network analysis with building information modeling (BIM) to facilitate the decision making for response operations. Building geometry is retrieved from the BIM model for graph construction and route finding. In this paper, the visibility graph (VG) and medial axis transform (MAT) are evaluated for graph construction. A hybrid method that combines VG and MAT is proposed, and encouraging results have been shown. Risks based on building materials and traffic of pedestrians are to be adapted for network edge costs to enable the lowest utility route finding in the future. The accuracy and efficiency for emergency decisions are expected to be improved for in-building rescue and evacuation operations.