Possible strategies and obstacles in the pathway towards energy transition of residential building stocks in Switzerland

The Swiss strategy for energy transition towards a sober energy world targets a 2000 W per capita society in 2050. This objective for an owner of a building stock is translated to a refurbishment of all existing residential buildings to near zero energy buildings, consuming less than 55 kWh/m2 of primary energy for heating with a rhythm reducing the overall energy consumption by an average of 2.6 kWh/m2 until 2050. The article analyses energy consumption of 10'000 residential buildings in Geneva Canton since 1994 and shows that the target of energy reduction at this rate has been achieved in the period 1994-2016, decreasing from 187 kWh/m2 in 1996 to 134 kWh/m2 in 2016. However, projections for the next 3 decades with the current refurbishment rhythm (0.8-1.5%) and the current real energy performance after deep refurbishment and energy upgrading, show that at this rate and with the performance gap not resolved, the final target will not be achieved. Based on the analysis of real energy consumption after refurbishment actions on statistically significant building samples and analysing the potential energy refurbishment actions of a 161 buildings stock, we have simulated possible and realistic ways to achieve the 2000 W society target.