In my graduation thesis I deal with the existing energy condition of Anton Martin Slomšek's primary school. Facility, which was built in year 2000, is located on the outskirts of Vrhnika city and is owned by community of Vrhnika. Through the first part of my thesis I discuss the legislation in reference to energy performance certificate for buildings, based on the new Energy act that was confirmed on 24th of February 2014 by the parliament. Then I describe the previously specified primary school and introduce the considered data for calculation. For calculation of energy analysis of the primary school I used computational method based on »Pravilnik o u�činkoviti rabi energije v stavbah« with the help of the TOST program. In the second part of my graduation thesis I list my results of the energy analysis and the efficiency of discussed primary school based on the »Pravilnik o uč�inkoviti rabi energije v stavbah«. Later on I analyze reasonable energy measures for the improvement of energy efficiency of the building, all based on my results. Emphasis of the measures is based on reduction of necessary energy for the heating of the building and on renewable energy sources. Throughout my thesis I also list all the necessary contents of calculated energy performance certificate.