A mixed-method approach to understand energy-related occupant behavior and everyday practices in multi-story residential buildings

In recent decades, attention has increased to investigating energy-related occupant behavior and everyday practices to contribute to bridging buildings' well-known energy performance gap. Understanding some of the mechanisms behind this gap, such as, the energy-related decisions and/or shared heating practices among occupants, could foster effective strategies for promoting energy efficiency. However, such mechanisms are not yet well identified, especially in residential contexts and low-energy buildings, where the relative impact of occupants' behavior is predominant. Aiming to contribute to tackling this knowledge gap, this article presents the results of a sequential mixed-method approach, combining quantitative and qualitative methods to study the energy-related practices of six occupants in five households of a multi-story low-energy household block located in Denmark. The households are monitored with sensors measuring heating use, room temperature, and heating setpoint temperature, enabling to capture human-building interactions at a high resolution. The quantitative analyses (data analyses) showed substantial differences in heating behavior and practices and thermal comfort preferences across households and over the seasons (from 90 to 301 heating days a year). Nevertheless, the qualitative analysis (semi-structured interviews) indicates shared practices regarding the use of the feedback display installed in each dwelling. This suggests that despite individual differences in preferences and habits, households living in the same building still share heating practices. The findings underpin the importance of the building managers' support and trust in improving feedback implementation and ensuring heating practices to support building energy efficiency.