Design strategies and measures to minimise operation energy use for passive houses under different climate scenarios

Here, the implications of different design strategies and measures in minimising the heating and cooling demands of a multi-storey residential building, designed to the passive house criteria in Southern Sweden are analysed under different climate change scenarios. The analyses are conducted for recent (1996-2005) and future climate periods of 2050-2059 and 2090-2099 based on the Representative Concentration Pathway scenarios, downscaled to conditions in Southern Sweden. The considered design strategies and measures encompass efficient household equipment and technical installations, bypass of ventilation heat recovery unit, solar shading of windows, window size and properties, building orientation and mechanical cooling. Results show that space heating demand reduces, while cooling demand as well as risk of overheating increases under future climate scenarios. The most important design strategies and measures are efficient household equipment and technical installations, solar shading, bypass of ventilation heat recovery unit and window U-values and g-values. Total annual final energy demand decreased by 40-51%, and overheating is avoided or significantly reduced under the considered climate scenarios when all the strategies are implemented. Overall, the total annual primary energy use for operation decreased by 42-54%. This study emphasises the importance of considering different design strategies and measures in minimising the operation energy use and potential risks of overheating in low-energy residential buildings under future climates.