Ranking of interventions to reduce overheating in dwellings during heat waves [conference paper]

Extreme weather events, including heat waves, are predicted to increase in both frequency and severity over the coming decades. Low rates of house building and a growing population mean there is a need to plan for climate adaptation of existing dwellings. This research uses dynamic thermal simulation to model the effect of a series of passive heat wave mitigating interventions for UK dwellings. The interventions include a range of additions and modifications to solar shading, insulation and ventilation. Results are presented for 19th century end terraced and mid terraced houses. Simulations were performed for buildings with the front of the terrace facing both north and south, with two different occupancy profiles: occupation by a family, at work and school during the day and by an elderly couple, assumed to occupy the houses 24 hours a day. The simulations were performed for a 4-day heat wave, during which daily maximum temperatures exceeded 350C. The results show the effectiveness of interventions that reduce solar gains through the building fabric, such as external wall insulation and light coloured walls. These are particularly effective for the end terraced house, which has a much larger external wall area than the mid terraced house. Control of solar gains through the glazing, by use of shutters and fixed shading, are also effective interventions, particularly for south facing rooms. The addition of internal wall insulation can help to reduce overheating for rooms occupied only during the evening and overnight. However, it is shown to increase the overheating problem, when compared to the base case houses, for living rooms occupied during the daytime. When considering interventions to reduce overheating in dwellings, it is therefore critical to take into account the residents and their corresponding occupancy profiles as well as house construction type, location and orientation.