This paper deals with searching accessible egress routes in case of emergency. The information about the building layout is extracted from the IFC file and stored in the graph representation together with current status of spaces and available equipment. The proposed method of knowledge-based adaptive search for egress routes is based on this graph representation. To support the decision-making process the rule-based reasoning system is applied, where rules for avoiding and eliminating threats are proposed. The user can introduce new information about the current situation to the system and thus the method provides flexible means for giving evacuation instructions. The presented approach is illustrated by examples of evacuation routes found in different types of emergency and visualized by the application written in Java.