Urban morphology and energy consumption in Italian residential buildings

The reduction of greenhouse gas emissions is a key issue to mitigate the climate change and the global warming. The European Union (EU) has defined important goals to 2020 and is promoting a low carbon Roadmap to 2050. The EU is pushing for the reduction of CO2, eq emissions by increasing buildings' efficiency and the use of renewable energy. In 2012, in Europe, the energy consumption was 1.1 GTOE and almost one third was spent in the residential sector. Between the European countries, Italy is in the sixth position for energy demand in the residential sector. Nowadays, most of the policies are related to the retrofit of the existing stock and to the diffusion of new high performing buildings (f.i. nZEB, Passivhaus, etc.). Anyway, especially in the areas with high urbanization rates, investigating how the urban form can affect the energy consumption of a city is extremely important for planning the expansion of new city districts. The aim of this work is to analyse how the urban form influences thermal energy consumptions. The specific characteristics of the buildings influencing the energy-use for space heating were considered as a constant, since, in the analysed district, only the buildings with the same compactness, type of envelope and period of construction were considered. The analysis is based on real energy consumption data, referred to the heating seasons 2012-13 and 2013-14, and available for about 500 residential buildings, mainly condominiums built between 1946 and 1980 and with similar compactness. Main results of the study demonstrate that space heating energy consumption at single building level is affected by its relationship with its neighborhood. This conclusion may support urban planners in the spatial definition of new urban areas, avoiding buildings with higher energy demand, lower air quality levels and more generally to improve the livability of urban spaces. Moreover, these results can be considered as a “preliminary - D; energy savings measures at no cost.