Adapting Nordic Buildings for Enhanced Summertime Resilience in the Face of Climate Change

In the face of escalating climate change impacts, understanding the resilience of buildings to extreme weather events, particularly in cold climates, is crucial for mitigating risks to human thermal comfort and well-being. This thesis addresses this issue by investigating the resilience of different buildings to climate change and its associated hot summers in Nordic climates. Through a combination of field measurements and simulation studies, the research assesses indoor overheating risks, energy consumption, and power demand in different building types, while also exploring the relationship between indoor and outdoor temperatures during heatwaves. The findings reveal significant challenges posed by high overheating risks in residential buildings, particularly in older ones in comparison to the newer ones designed based on the latest building codes. The study highlighted the effectiveness of passive strategies in mitigating risks. However, results showed that there is a need for mechanical cooling systems in residential buildings to ensure comfortable and healthy indoor temperatures during current and future heat events. The needed cooling electricity was shown to be considerably small compared to other energy consumptions in the buildings. Additionally, the study identifies strong correlations between indoor and outdoor temperatures during the hot summers that weakened during the prolonged heatwaves. This highlights the complex and dynamic nature of these relationships under different environmental conditions and emphasizes the importance of considering extreme heat events in the design and operation of buildings in cold climates. In office buildings, all-air and air-water systems were found to perform equally in terms of cooling energy consumption and indoor temperature conditions under a changing climate. While the maximum cooling power demand would be higher with the all-air system (ventilative) during extreme weather conditions. However, the cooling electricity increased up to 47% in the future average climate and up to 128% in the future extreme climate with the air-water system, and up to 51% in the future average climate and 108% in the future extreme climate with the all-air system by 2050 depending on the CO2 emission scenario.