Defining Criteria for the Selection of Measures to Increase Energy Efficiency in Public Buildings

Buildings, although one of the largest energy consumers in the world, also represent big potential to reduce energy consumption, dependence on fossil fuels and carbon dioxide emissions, through the implementation of energy efficiency measures. Improvement of energy efficiency of existing buildings requires a dedicated, serious and detailed approach. Investors are often guided by economic criteria, which greatly influence on investments and interventions, potentially causing some negative side effects (comfort reduction, use of energy-intensive materials, etc.). Therefore, it is very important to rely on methods that provide detailed and affordable cost, technical and environmental analysis. Energy efficiency methods are often based on simple methods such as research, estimation of energy consumption, preliminary design, estimation of energy savings and financial cost-effectiveness. For example, in energy audits of buildings, annual energy consumption and cost-effectiveness are considered for analysis. For a more detailed assessment, a calculation tool based on the calculation of energy consumption of particular facility and the estimation of energy savings after the proposed energy efficiency measures is being used. The proposed measures generally represent a classic scenario of energy efficiency measures. In this paper, factors such as comparison of the share of fossil fuels and renewable energy sources (RES), the estimation of cost-effectiveness of the use of renewable energy technologies, aspect of embodied energy in materials and life cycle assessment in buildings are being considered. This paper defines the criteria for the evaluation of scenarios (functional groups of measures) for increasing energy efficiency of the building, which include, in addition to energy and economic aspects, environmental aspect. The six criteria have been defined for evaluation of energy efficiency scenarios related to: annual energy consumption, total annual primary energy, share of RES in primary energy, direct and indirect carbon emissions, embodied energy in applied materials and investment per scenario. For each criteria an expression for its calculation is given. Defined criteria are calculated for six scenarios of increasing the energy efficiency of Mechanical Engineering Faculty, University of Sarajevo. Based on the calculated different values of criteria of considered aspects, it is possible to identify in more detail way critical points, advantages and disadvantages of different combinations of energy efficiency measures, which can further serve to identify the best strategy necessary for evaluation of energy performance of the building before and after the intervention.