The extent of cool materials usefulness is dependent on the severity of external conditions and internal heat gains. Heat transfer to the internal space by conduction is therefore reduced while the magnitude of the reduction will be determined mainly by the solar radiation intensity, the temperature difference between inside and outside as well as the constructional characteristics of the roof. Cool materials work by reflecting solar radiation and therefore rejecting solar heat gains at the opaque external surfaces of the building. Rejection of solar gains is the aim of passive cooling strategies in any type of building and any climatic region. Heat island is related to the increase of urban temperatures compared to the suburban areas because of the positive heat balance. Heat island is the most documented phenomenon of climatic change. Increased urban temperatures have an important impact on the energy consumption of buildings mainly during the summer period. Keywords: urban heat island, cool roofs definitions, standards, European policy The European legislation as well as the challenges for cool roofs’ products in the European context is discussed. The promotion and rating of cool roofs in Europe is pinpointed. Various definitions of cool roofing materials are analysed and presented. Kostas Gobakis Technical University of Crete, Greece Synnefa University of Athens, Greece, Meier Sika Services AG, Evans Huntsman, Kolokotsa Technical University of Crete, Greece & European Cool Roofs Council, Santamouris University of Athens, Greece, status of cool roofs in the European context is presented.
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