A GIS tool for the calculation of solar irradiation on buildings at the urban scale, based on Italian standards

•The Italian EBP calculation is based on a tabular methodology to assess solar irradiation on buildings.•The evaluation of the necessary input obstruction angle relies completely on the energy certifiers.•A questionnaire survey is carried out to assess the most adopted assumptions on its calculation.•A GIS tool is proposed to make an objective calculation that complies with legislation procedures.•The results are tested with a solar simulator.