Evaluation of current and future energy performance of buildings at the urban scale: two cases in southern Italy

Public Authorities (PAs) need to define cross-cutting strategies for urban planning including policies for sustainable and energy-efficient buildings and innovative urban solutions. Italian cities often suffer a lack of technical information about the municipal building stock, especially in historical/old existing buildings, engraved by the PAs inability to use overly expensive and complex modelling software. The article presents a bottom-up Urban Building Energy Model (UBEM) tested on the historical city centres of Matera and Catania, in Southern Italy. The proposed UBEM defines Virtual Archetypes (VAs) that, by inheriting the most representative characteristics of the reference building stock, such as building materials and typologies, surrounding context and typical energy system specifications, represent the current energy performances. Each Envelope and HVAC refurbishment scenarios are then considered for the estimation of VAs future energy performances. Lastly, predefined decision trees associate VAs with the city buildings modelled in QGIS. The approach uses raw input data from open sources (i.e. OpenStreetMap) and EnergyPlus for the energy performance assessment. As a result, 34 not refurbished VAs are defined and associated for 900 buildings within Matera city core and 28 VAs for 9600 buildings within the city centre of Catania. In this way, each city building is distinguished with a set of values of primary energy for heating, cooling, DHW and lighting and correspondents value of CO2 emissions. Concluding, the proposed approach allows to characterize the energy profile of each building of the area of interest, storing these data in a GIS readable scheme for urban planning purposes.