Improved energy efficiency in buildings is a major part of the overall strategy to reduce fossil fuels use and thereby mitigate climate change. In this study, we present and demonstrate an approach for economic analysis of building energy efficiency measures, and investigate the profitability of energy efficiency renovation measures for a Swedish multi-family building. The energy renovation measures include additional insulation to basement, exterior walls, and roof and improved windows. They are analysed when applied either singly or in packages. We find that the cost-effectiveness of the building envelope retrofit measures is very sensitive to the economic-related parameters applied including, real discount rates and energy price increase over time. Cost optimal final energy savings for the energy renovation package varies between 29% and 38%, depending on the choice of real discount rate and energy price increase. This study shows the significance of different building envelope measures and economic-related parameters in achieving large energy savings from building envelope renovation cost-efficiently.