The impact of building function on energy performance class under identical building parameters

Abstract

Hungary’s Decree 9/2023 of the Ministry of Construction and Transport defines the energy performance requirements and calculation methodology for buildings, setting a limit of 76 kWh/m²a of non-renewable primary energy demand for residential buildings. The research examines how energy performance ratings change across different building functions using three sample residential designs with identical geometry and structures. Various HVAC systems (e.g., gas boilers, heat pumps, with and without mechanical ventilation) were applied to the models. The results show that building function has a significant impact on energy classification. The study contributes to improving the assessment of buildings undergoing a change of use.