The construction of the rooftop extensions is the viable way that makes the housing refurbishment less costly for tenants, enables to augment the demand for the housing stock in the built area without additional requirement for the housing space. The sustainable and energy efficient housing units in refurbished buildings and on their rooftops can reduce utility costs, provide the flexible and often very elegant housing spaces, etc. In spite these advantages there are many obstacles that inhibit the wide utilization of the roofs for the new housing units. We are dealing with these problems from Slovakian as well as from wider European perspective. We also present the partial research program results from the EU Intelligent Energy project SURE-FIT