This paper presents and demonstrates a method for analysis of cost-effectiveness of energy efficiency measures for buildings. Based on the method, cost-optimal energy efficiency measures are calculated considering total and marginal investment costs as well as net present value of energy savings for the measures under different technical and economic scenario. The method is applied to a 1970s Swedish multi-family building to explore the profitability of different energy renovation measures when implemented individually or in packages. The measures analysed include improved thermal insulation for exterior and basement walls as well as attic floor, improved new windows, efficient electrical appliances, efficient water taps, and exhaust air ventilation heat recovery systems. Our results show that the economic viability of the retrofit measures is sensitive to the techno-economic parameters used including, real discount rates, energy price increases and technical lifetime of retrofit measures. Still, about 34–51 % reduction of final heat demands is economically viable for the analysed building. Resource-efficient taps is the most cost-effective measure while improved thermal envelope insulation for exterior walls is the least cost-effective among the measures analysed for the studied building. This study shows the significance of different technical and economic parameters in achieving deep-energy savings from renovation of a building in a cold climate.