Climate change intensified the need for sustainable solutions to mitigate urban heat and reduce buildings’ energy consumption. Among the most promising strategies, there are cool roofing materials, particularly those utilizing passive daytime radiative cooling (PDRC) technologies, which enhance building thermal performance and minimize the reliance on energy-intensive cooling systems. PDRC materials reflect solar radiation and emit heat as infrared radiation through the atmospheric window. This mechanism enables them to achieve surface temperatures below ambient temperature. In this study, developed within the project 21GRD03 PaRaMetriC founded by the European Union, the performance of PDRC materials with a solar reflectance of 0.93 and thermal emissivity of 0.877 (5–50 μm) and 0.889 (7–13 μm) is analyzed. Four building types are simulated in the EnergyPlus engine, including a six-story multifamily building and three single-family houses. These buildings are located in southern European cities with varying climates: Milan (Italy), Athens (Greece), Marseille (France), and Varaždin (Croatia). Two scenarios are evaluated: a baseline scenario using conventional roofing materials and two alternative scenarios employing PDRC materials, considering a constant or spectral emissivity-dependent model. Results demonstrate that the constant emissivity model overestimates PDRC performance. Considering the spectral emissivity-dependent model, in the coldest climate (Varaždin), the heating demand increase outweighs cooling savings, leading to a net rise in primary energy consumption with respect to the baseline scenario, equal to + 7.3%. Conversely, in Athens, the warmer climate enhances the effectiveness of PDRC, and total energy consumption decreases by − 5.4%.