The refurbishment of the Dutch post- war residential building stock provides a great potential for energy and CO2 emissions savings, since a large number of buildings were built before 1975 and under low or no energy standards. However, their refurbishment and especially zero-on-the-meter, is too expensive and it is not possible to find the required funding. Following the guidelines of the Project MVI-Energie, which proposes disconnecting from the gas and decreasing the heating demand (that can reach up to 70% of energy demand) by insulating as such to be able to change to low temperature heating. This study focused on portiekapartments and proposed a refurbishment strategy to achieve LT-ready, while lowering the costs, time and nuisance to the residents. The facade criteria regarding the energy efficiency are the results of a parametric simulation, which includes every significant facade variable and the innovative process of applying external insulation at the optimal percentage to achieve LT-ready. The results of this simulation - diagram of solutions- can be used to upscale the research and as a guideline to quickly and easily understand if this strategy can be applied to other buildings and what it will need, based on their facade characteristics. For the technical solution a prefabricated small size insulating panel is used, that reinforces the economically feasible and fast refurbishment idea. An important aspect of the solution is to be adaptive (for example provide different cladding options) and can be part of a two-step refurbishment by providing the opportunity in the future to be continued to deeper refurbishment if needed.