Impact of U-Values in Evaluation of Implemented Energy Efficiency Measures and Energy Savings in Public Buildings in Context of Kosovo Legislation

Abstract

-The purpose of this paper is to articulate the immediate need for review and improvement of Kosovo Building Regulations and Codes in the field of implementation of EE measures and specifically reducing U-values for all building envelope elements, to be comparable to European Standards, and present a specific contribution for EE measures in public building stock in Kosovo as the real potential for huge energy savings. In this paper the results of the several years’ long research on the impact of implemented energy efficiency measures in the 70 selected public buildings are presented, in light of calculated U-values with a brief description of the constituent elements of the building envelope and their corresponding U-values, such as external walls, windows, doors, floors and roofs, comparing their impact in the phases before and after the implementation of Energy Efficiency measures. A building designed to use the minimum quantity of thermal energy for heating and cooling to achieve a healthy environment and thermal comfort is considered an Energy Efficient building. The U-values of the building envelope are the dominant factors in its thermal performance and play an important role in reducing the energy consumption of buildings. Many studies confirm that in cold climates, from the total annual energy consumption for heating and air conditioning of public buildings, approximately 50% of the energy is consumed through the heat transmission of the building envelope. The achieved results after implementation of EE measures have shown significant improvement of U-values for both opaque parts of building envelope and belonging fenestration compared with the referent values set in Kosovo Technical Regulation which is actually in use for designers in Kosovo. Depending on wall thickness and installed insulation achieved, results of U-values for external walls were 0.31-0.35 W/m2K, much lower than recommended in old technical Regulations, lower than recommended by ANA_IAE, but still higher than values from Finish and Norwegian building codes. Calculations have shown that in the case of implementation of improved U-values according to the Finish building code the impact of walls on U-values in overall energy savings is around 36.86%. Windows and doors look the sensitive part of the building envelope and show that it is more than the required strengthening of requirements in future Kosovo Building code reducing the U-values for doors and windows at 0.8 W/m2K. Analysis has shown huge improvement and potential increase of energy savings with 55.25 % for part of fenestration. Detailed analysis of the collected U-values data for roofs has shown that there is sufficient space for improvements in Building codes and it is a highly recommended change of existing criteria and at least application of the values from EU building codes. With this change, potential energy savings in part of roof covers might be 44.24%. Working as an EE expert in Kosovo Energy Efficiency Agency (KEEA) and World Bank (WB) and European Union (EU) projects, the author has identified the necessity of improvement of actual Kosovo legislation in the field of EE policies for public buildings, addressing the importance of the appropriate building envelope’s thermal insulation to reduce its thermal losses and stipulating the impact of the U-values in the evaluation of implemented energy efficiency measures and energy savings in public buildings. The overall energy savings with applied EE measures and potential energy savings in case of improvements of Kosovo Technical Regulation according to recommended standards and EU countries’ experiences are presented in a separate table showing economic net savings, an average payback period and overall potential reductions of CO2 emissions. The presented results indicate a recommendation for further studies that may include other building typologies and may disclose additional differences between the energy performance criteria in the analysed building codes.