• lighting quality.
• indoor environmental quality
• IEQ weighting scheme
• Hospitals
• health and comfort indicators
• classrooms
• multicriteria analysis

The built environment is intended as a physical and social environment that must provide those environmental conditions that can promote wellbeing, health, productivity and interactions between people. Studies on people's well-being and comfort in indoor environments are taking on growing importance and the need for refined evaluation tools that allow them to obtain a picture of the current state and to identify all the aspects that should be improved (to ensure high levels of comfort and well-being) is increasing. The Indoor Environmental Quality (IEQ) is based on four main environmental factors that simultaneously affect human perception: thermal environment, lighting, acoustics, and indoor air quality. The aim of the research activity was to create a method for the evaluation of IEQ in existing buildings aimed at identifying critical aspects and creating criticality rankings. Before the design of the new evaluation method, for each environmental factor, the main human response models were analysed and the indicators for the health and comfort evaluations were collected. In addition, an in-depth study of the relative importance of each environmental factor in the overall IEQ assessment was conducted. In detail, the weights proposed in the scientific literature were studied and three subjective surveys were carried out in which the students of the School of Engineering of the University of Pisa were involved and a total of 1434 filled questionnaires were collected. Finally, the new evaluation method was applied to different observation scales from the whole building to the single workstation. In particular, two different case studies were used: the University Hospital of Pisa and the School of Engineering of the University of Pisa.