In the last decade, the service sector had a very rapid growth, due to the so-called “tertiarisation” of the economy. Accordingly, the energy consumption, mainly attributable to public and private buildings, is rapidly growing, thus making buildings energy saving one of the main issues of the energy policy at regional, national and international levels.
To this aim, we developed an effective methodology to improve energy efficiency of the service sector buildings. This may represent a handy great opportunity to save natural and economic resources, especially where the buildings structure and the technical systems are old, the maintenance activities are not carefully carried out or a systematic energy management is not applied. Nevertheless, actions in this direction are often considered too expensive and complicated, if compared with residential energy optimization, because of the big extension, the variety of activities and the high number of occupants typical of the service sector buildings. The developed approach for energy audits aims to investigate the energy aspects of existing non-domestic buildings in a structured way, in order to clearly identify their energy saving potential and to improve their energy performances. The main goal of the study is defining a general methodology to analyze the current energy use and consumption considering a limited number of their peculiar elements such as dimensions, activities, users behavior, technical systems data and energy bills. Furthermore, these informations are completed by an appropriate energy measuring campaign. All the possible energy uses in service buildings are taken into account (i.e. lighting, ventilation, air conditioning, hot water production). The results obtained from the analysis allow to evaluate a global level of building energy efficiency, and to identify those single areas, specific systems or everyday activities where energy is wasted. These considerations also provide basis for programming cost-effective energy saving action plans.
The effectiveness of the proposed methodology is demonstrated through a case study for an Administrative Center building in Rome, Italy. Results demonstrate the methodology reliability and the cost reduction potentialities.