Evaluating the environmental efficiency of passive climate change adaptation measures in the built environment: Exploring synergies between cooling energy reduction and environmental impact of passive climate adaptation retrofit measures in Gothenburg

Abstract

In an increasingly warming climate with higher frequencies of heat waves and extreme heat, literature indicates that cooling will have increased relevance even in the Nordic climate. To ensure thermal comfort during summers and limit the use of electricity for air conditioning, climate adaptation in the form of passive cooling measures can be implemented. This study aims at evaluating the environmental efficiency of passive cooling measures that could be implemented in future renovations of the Swedish building stock, to illustrate how interdisciplinary assessments could aid in greenhouse gas emission reductions when considering climate change adaptation. A multi-family residential building built in the 1970s is used as a case study and the assessed measures include added insulation, improved glazing, added solar shading, improved solar reflectivity of façade material, and natural ventilation. The measures were assessed on their ability to reduce peak cooling demand, annual cooling demand, overheating hours and maximum temperature during peak conditions using an hourly energy simulation model, and the environmental impact of the measures was calculated based on material use. The study concludes that using natural ventilation is the most environmentally efficient passive cooling measure due to the devoid of environmental impact. However, to sustain thermal comfort in a future climate it could be beneficial to include complementary passive measures. Changing to triple glazing is the second most efficient in all aspects of thermal performance and has a similar environmental impact to the other assessed measures, and the option is consequently the next recommended measure, followed by the less environmentally efficient solar shading option. A combination of all measures is associated with the greatest cooling reduction potential; however, it poses a large trade-off in terms of environmental impact. The study illustrates that the inclusion of environmental impact when assessing climate adaptation measures is useful to provide guidance on GHG reduction when implementing climate change adaptation measures.