Building design in a changing climate – Future Swiss reference years for building simulations

Abstract

With global climate change, temperatures in Switzerland are projected to rise in the coming decades, according to the national climate scenarios CH2018. Associated with the mean temperature increase, heatwaves are expected to become longer, more frequent, and more intense. The changing climate will affect the indoor climate as well as heating and cooling needs. In building design, these climatic changes have to be planned for today in order to ensure a comfortable indoor climate in the future. In collaboration with practitioners, a reference climate data set for the future is created that specifically targets building designers and engineers. The data set consists of hourly weather data of one-year length based on the Swiss climate change scenarios CH2018. These future reference years are representative of two time periods in the future: one around 2030 and one around 2060. Climate change uncertainty is considered by using two emission scenarios (RCP2.6 and RCP8.5). Reference data for the future is provided not only for a typical year (called Design Reference Year, or DRY) but also for an above-average warm summer. The data is available at the sites of 45 measurement stations across Switzerland, including four stations inside major cities to take the urban heat island effect into account. The generated climate data set is applied to a building model to provide an application example. The results point out that the cooling needs will substantially increase, which is why an adaptation of the building design to the changing climate is vital.