This study presents a comprehensive approach for calculating buildings' energy contribution to the formation of urban heat island (UHI). For this purpose, the heat released by building envelope and HVAC system has been taken into account, while longwave radiation to the sky has been excluded from the calculation, as it is not so relevant to the UHI effect. Several strategies to minimize the UHI phenomenon and their effects on the heat released have been considered along the whole-year period. An existing educational building has been selected as case study. The selected building is considered representative for a wide range of tertiary buildings with an intermittent operation mode. Results have been obtained by dynamic simulation models, which have been validated with measured indoor air temperature data. Despite a moderate reduction of the energy contribution to the UHI effect during winter, which is commonly considered unfavorable, the effectiveness of cool coating application in reducing the heat released during summer has been clearly demonstrated. On the other hand, it was found that a higher level of envelope insulation is not yielding a significant reduction of the heat released, especially during summer. (C) 2015 Elsevier B.V. All rights reserved.