Energy performance for residential building – comparison between theoretical method and real measurements

This paper presents an energy performance of residential building (two – family building) located in Poznan. Both apartments were analysed separately. By using a method of energy performance calculations valid in Poland, a theoretical energy performance had been prepared. The calculations were conducted assuming real changeability of climatic data in years: 2010–2017. The real energy performance was prepared based on actual gas consumption for the purpose of heating and domestic hot water preparation (DHW) within the years of measurements taken, being a subject of analysis. The findings from this study revealed that a theoretical energy performance significantly deviates from the results obtained by means of energy consumption measurements, which resulted from variability of basic climatic data over time and also from theoretical usage profile of the apartments.