This work regards the development and the validation a simplified model for building cooling energy requirement. It aims to be as similar as possible to the procedure adopted for calculating the winter heating energy demand of the UNI-CEN standards. The latter, a procedure based on a steady- state model, including one or more corrective numerical-experimental correlations, that take into account in a simplified way – and thus approximately – the effects of thermal capacities on the phenomena under examination. The critical evaluation of the first results suggested changing the approach, in the model correlations developing process, from a physical parameters based to a building typology based. Nevertheless, following such approach, a good agreement has been achieved between the results of a detailed hourly simulation and the values predicted by the simplified model. Indeed there is evidence that acceptable results can only be obtained by providing a correlation by building archetype. To avoid such massive work in developing building archetype based correlations, it was developed and validated a more complex simplified dynamical model, using an average monthly day, and based on the approach followed by the prEN 13792  standard for the free- floating summer room temperature profile evaluation. The results show that the use of such model did not increase the quality of the results, due to too strong simplifying assumption even if more physically based, especially if compared to the full hourly dynamical simulation (i.e model based on physical equation with few simplifying assumptions).