Overheating in existing and renovated Danish single- and multi-family houses

This study compares the overheating risk of eight typical Danish residential buildings for today and future climate scenarios. The study includes four single-family and four multi-family houses, various renovation strategies, and two occupancy loads. Building performance simulation is employed to conduct 3012 simulations (using IDA-ICE), and the comparison of the overheating potential is conducted using the Indoor Overheating Degree (IOD). Results showed that the multi-family houses have a slightly higher overheating risk than the single-family houses. The building with the highest overheating risk was the one-story single-family house (1951–1960) characterised by a large unshaded glazed area. The most effective renovation strategy to reduce overheating resulted in being the window replacement. For the single-family houses, the renovation of the baseplate or the floor to an unheated basement was causing overheating. As for the multi-family houses, renovation of the external wall led to the largest increase in overheating in relation to the unrenovated case. The investigation of the future climates showed that overheating could increase with rising outdoor temperatures, whereby the interaction between temperature and solar radiation is a crucial factor.