An average temperature increase of 2oC over the last 140 years in Toronto may not seem significant, but in reality heating demand for buildings will go down by impacting natural gas usage while cooling demand will go up by impacting electricity-usage. For preparedness against hot summer in cold climate, passive cooling needs to be adopted for building energy efficiency. In warm climate, cool roof technology proves effectiveness in reducing cooling energy demand of buildings but its use in cold climate is not much seen. Thus it is interesting to investigate the effectiveness of cool roofs in cold climate. This study investigates the properties of cool coatings available in North America, their performance on aging and energy saving benefits. The first phase of research includes selection of building, collection of information, field measurement of surface temperatures of the studied building and also lab testing of collected samples. The second phase includes energy modelling of the studied building with validation to understand their energy saving benefits. Finally the most effective cool coating for the studied building is recommended.