Densification-refurbishment of existing buildings could be an interesting solution both to improve energy performance and to contribute to the densification of urban areas, two declared objectives of recent legislation at the Swiss level. However, so far, operations of this kind have not been a resounding success. The eREN2 study demonstrated why : mainly a lack of economic interest. This paper is to be seen as an extension of the eREN2 study, exploring several options for making these operations financially attractive and the consequences of the decline of return on investment on their attractiveness. The outcome is that alternative options such as densification-refurbishment conceived as partial real estate development projects and the diminishing expectations return on investment on the real estate market could result in densification-refurbishment projects being a very valuable solution in the future both financially and in terms of energy saving.