The importance of input data in the study of urban surface use and optimization

Urban areas are responsible for 75% of global greenhouse gas emissions and 60-80% of total energy consumption, contributing significantly to the ongoing climate change. In this regard, research and development of renewable energies are trying to face the environmental problems associated with the use of fossil fuels, as well as the need to improve energy efficiency and sustainability in cities. To pursue sustainable goals, the use of active and passive solar strategies can be implemented to achieve a healthier and more comfortable urban environment. The survey of the current conditions and the simulations of the actual situation are of fundamental importance to verify the improvement given by certain interventions. This is necessary to understand the current response of buildings and urban surfaces to solar radiation and the propagation of effects that could become problematic and damaging from many points of view. The climatic data, related to the air temperature, the relative humidity, and those related to the current performance of materials (the reflection degree, the physical characteristics, and the mechanical conformation) will be therefore crucial. Since this is the point from which all future results will then come, the selection of all the input data will be very important for the evaluation of the new design assumptions. This contribution aims to explore the issue of evaluation, accuracy, and choice of data, analyzing the difference in results according to the different uses, and identifying a methodology to approach the issue.