Assessment of buildings heating consumption and technical retrofit strategies at urban scale

Cities have a key role in achieving the 2030 EU environmental, energy, and climate targets, in particular the residential building sector, which is the major source of energy consumption in urban areas. The Italian building stock is composed of over 50% of buildings built between the '50s and '80s, which have obsolete thermal system technologies and inefficient envelopes. Urban energy planning should be used as a resource to highlight the major criticalities in existing buildings and to correctly identify the strategies to adopt. This thesis work analyzes residential buildings of Milan to evaluate actual heating energy consumption and their possible reduction due to different retrofit actions. Only open data from EPCs and the Regional cadastre of thermal plants have been used as a source of thermo-physical, geometrical, and technical information. EPCs have been cleaned and missing information about thermal plants have been recovered through a simple statistical analysis of the cadastral data set. Bin method has been applied to evaluate building energy consumption, before and after retrofit strategies. Missing and not consistent information of EPCs limits the development of a more refined method. The choice of different retrofit scenarios has been done according to the most diffused solutions, considering both passive and active ones. The application of different strategies has been driven by the analysis of the distribution of heating energy consumption of buildings, differentiated by some variables, like energy class or thermal system technologies. A spatial visualization has been realized using a Geographical Information System (GIS) to highlight urban areas with the highest consumption, at building and census tract levels. A map visualization, supported by technical analysis, simplifies the problem detection, to define correct solutions in terms of energy efficiency.