Predicted and measured user-related energy usage in newly built low-energy schools in Sweden

Literature and experience show that the differences between calculated and measured building energy performance still exist. The literature shows that user-related parameters are significant with regard to energy performance in low-energy buildings and this means that the choice of parameters is one of the main factors leading to this difference. However, the parameters themselves are associated with uncertainty when predicting and calculating their effects. One of the identified research gaps is the lack of data on behavioral energy use and profiles. The aim of this study is to provide relevant feedback, which will help the building industry and research communities to predict more accurately the user-related impacts on energy performance and, subsequently, enable reduction of the differences between calculated and measured energy performance. This article analyses measured user-related parameters and building energy usage in seven recently built low-energy schools in Sweden. Regression analysis is applied when analysing the parameters and their influence on energy usage. With the help of the measurements carried out, all the studied schools were determined to be low-energy schools. The results show differences between calculated and measured building energy performances in the studied schools and these vary from -44 to +28%. At least 33% of measured energy usage depends on the user-related parameters. Ventilation rates and running times as well as space heating set points were found to be the user-related parameters that have the most significant effects on total energy usage. Finally, some important recommendations for good building operation practice and measurement methodology are presented.