Energy retrofitting effect on perceived indoor climate: A case study of Estonian multi-family buildings

Sammanfattning: Energy renovations are an important measure for achieving the European Union’s target of climate neutrality by 2050. To meet the EU goal, Estonia needs to fully renovate 14 000 multi-family buildings by that time, affecting the indoor environment conditions of a large number of people. To gain knowledge for the upcoming renovations, the experience of the people living in the multi-family buildings is a valuable source of information on how the current energy renovation methods affect people’s indoor climate perception. The study compared occupants’ indoor environment experience in the same type of buildings in five different groups, where one of the buildings was renovated in recent years and the other building was still in its original state. The case study buildings were five renovated and six non-renovated multi-family houses built between the 1960s and 1990s in the Tallinn area in Estonia. A questionnaire survey regarding inhabitants’ indoor climate experience and window airing habits was conducted and information about energy retrofitting methods used in the buildings was gathered. Additionally, buildings’ measured energy consumption was examined. The result showed that occupant satisfaction with indoor climate in terms of thermal comfort and air quality could be improved significantly in renovated buildings, compared to their control building in the original state. Still, there are factors such as overheating in the summer, insufficient soundproofing between the apartments, and smell disturbances from inside and outside the building that the current level of renovation solutions does not resolve. However, energy renovation benefits to the occupant include reduced heating energy consumption and increased satisfaction with their overall living environment.