Impact study of the climate change on the energy performance of the building stock in Stockholm considering four climate uncertainties

This work describes the research conducted in order to assess possible changes and uncertainties in future energy performance of the residential building stock in Stockholm. The investigation is performed on a sample of 153 existing and statistically selected buildings and covers the period of 1961–2100. Four uncertainty factors of the climate have been considered: global climate models, regional climate models, emissions scenarios and initial conditions; thereby, 12 different scenarios have been created. Energy performance of the building stock is studied by looking at the overall heating and cooling demand and the indoor temperature. Three cooling strategies of the building stock were evaluated: natural, natural and mechanical (hybrid mode) and only mechanical. To decrease the number of simulations, a method for sampling the climate data has been developed and tested against Sobol quasi-random sampling method. Results of the investigation show that for all the climate scenarios the future heating demand will decrease at the end of the studied period, i.e. around 30 kWh/m2 (30%) lower than before 2011, while the cooling demand will increase. Results for the heating demand can differ for about 30% between the scenarios and even more for the cooling demand. Since the current and future cooling demands are rather low, the natural cooling can be the safe choice for mitigating overheating. Uncertainties of the climate data can affect the energy simulation results, but it is possible to rank them and introduce margins to the design based on the importance of the uncertainty factor