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

A summary on the state of the art of GIS tools for urban solar analysis and the standard algorithms for the calculation of the solar irradiation is also provided. For the study of the practitioner's approach in the use of the standard calculation a questionnaire is set up. The work then illustrates the methodology approach adopted for the tool developing and testing. The discussion focuses on the compliance of the results with standard calculation and on solar irradiation values reliability. Such consistency has been assessed via a sensitivity analysis based on different ideal cases. In order to assess the reliability of the results of the GIS tool, a comparison with the values obtained from a dynamic solar simulation environment (Daysim) is performed.