NZEB schools: global sensitivity analysis to optimize design features of school buildings

In the context of “2030 climate & energy framework” and “2050 low-carbon economy” it is essential to understand which the elements that affect most buildings energy needs are. The main aim of this study is to identify and to optimize these factors in order to improve energy performance of schools by minimizing energy consumption. The study presented was carried out through a sensitivity analysis in order to determine which factors most affect energy consumption with respect a school typological model adopted as the reference model considering climate zones D and B. The analysis evaluated: shape, different materials for insulation, thickness of insulation layer for façade and for roof, window to wall ratio (WWR) for each orientation, type of solar shading for south orientation, integration of vertical solar shading for east and west orientation, contribution of ventilation and some parameters related to systems. Results pointed out that for this type of buildings the ventilation requirements for air changes is the factor that most affects the energy demand both for heating and cooling. At the same time also the variation of shape, of thickness insulation layer for roof and of WWR influence is significant.