Bogotá D.C. is an urban city where disasters of high environmental impact occur, such as structural fires, whose effects on the population represent large-scale damages for most of the civilian dimensions. A scenario of these catastrophes are urban buildings, of which the risk is directly proportional to the ignorance of policies for the management of disasters such as the environmental properties of a structural room, the measurement of temperature and air quality, among others. Therefore, this article presents a prototype of a monitoring system on buildings in urban areas using mobile devices and technologies based on IoT, for the prevention of structural fires, supporting the monitoring process in a fuzzy inference system, whose heuristic model transforms the environmental properties captured through electronic sensors, and sends the resulting information to citizens' mobile devices. Finally, the results and conclusions of the prototype implementation are presented in an environment supervised by an expert, and the future work derived from this research.