Fire emergencies in Nigerian public buildings remain a critical safety challenge, causing about 7000 incidents annually, over 1000 fatalities, and property losses exceeding ₦5 trillion between 2013 and 2018. This study proposes a proactive, low-cost integration of Building Information Modeling (BIM) and Geographic Information Systems (GIS) to support fire evacuation planning. A mixed-method approach was adopted, combining primary field data, 2D CAD floor plans, and national building code standards with qualitative insights from fire service experts. Four multi-level university buildings were modelled in Revit and integrated into ArcGIS Pro to generate network models for evacuation simulations. Six fire scenarios were tested using Dijkstra and Ant Colony Optimization algorithms. Results revealed that shortest routes, though efficient in distance, were not always the safest, as safer routes involved longer distances and times but reduced hazard exposure. Triangulation of simulation results, spatial modelling, and expert interviews validated the feasibility of BIM-GIS as a cost-effective tool for proactive emergency planning in resource-constrained environments.