In this paper the authors shared the first steps of a recent approved research project regarding sustainable cities and urban transformation needs towards a smart city model. These steps are the start-up of one of the working package of the project regarding energy efficient buildings and smart buildings solution. An experimental campaign was started in several houses in order to define the comfort and using pattern of inhabitants and these data that will be introduce in the simulation tool to create the base model. In the same time the numerical model is prepared and a number of archetypes were defined and explained. Examples from other international initiatives were referred, where research community try to find the more accurate approach of the Smart City by developing European and International research and networking projects.