Renovation of Swedish single-family houses to passive house standard: Sensitivity analysis

A third of Sweden’s two million single-family houses were built in the period 1961-1980, and many of them are in need of renovation. Energy use in these houses is high, and they are fairly homogeneous in technical terms. A previous study of four reference houses showed that final energy use could be reduced in theory by approximately 65-75 % after renovation, by implementing conventional passive house components renovation measures. This paper evaluates the results and uncertainties arising from the previous study by performing a local sensitivity analysis of the most important input parameters, such as number of inhabitants, climate zone, orientation of the houses and alternative renovation measures in a Swedish context. The results presented in this paper show that the previously estimated final energy use reduction can be increased even further, to 75-80 %, by introducing additional renovation measures. The climate zone was shown to have the largest impact, with twice as much space heating required in the coldest evaluated climate compared to the mildest. The impact from inhabitants was less than expected, due to a counterbalancing impact on the final energy use from internal gains and domestic hot water.