In the wake of a spike in façade fires on high-rise buildings, an online tool was developed to assess the likelihood and consequence (risk) of a fire spreading over the exterior facade system of a building, for existing buildings over 18 meters high with a business or residential occupancy, including hotels. The risk assessment methodology is based on a two-tier approach that prioritizes or screens of multiple buildings based on a short questionnaire, then generates a fire risk assessment of each building in order of priority. Process A enables the consideration of the hazards associated with the façade system, including materials of construction, continuity of combustible materials over the height of the façade, and ignition sources. Process B enables the consideration of the fire-safety provisions within the building and their condition. The methodology requires the user to choose pre-defined answers to a range of questions. The answers to these questions inform the likelihood and consequence of an event, and therefore the risk. The application scores the risk posed by a combustible facade system on a building based on six look-up matrices of likelihood versus consequence.