Two-third of the residential building stock in Germany is older than 35 years and bears a lot of potential for energy savings. The German Federal Government has therefore committed itself to reduce the primary energy in the building sector down to 80 percent by 2050. This ambitious target requires doubling the energetic building refurbishment rate from its current 1-percent level of the building stock per year. The national strategy basically contains two key elements: stronger building requirements and subsidies on bulding refurbishment. This paper analyses how these programs affect the incentives and the profitability of retrofit investments and discusses the main drivers and barriers that affect the investment decisions made by the owners and landlords. Based on several datasets we show how initial returns depend on influencing factors like saving measure, renovation scope, building type, building age, housing conditions, rents and market situation.