Cities are the main leak of Country. The process of urbanization denounces the need to transform settlement from a weak point to the strength of the future sustainability. Urban shape is deeply related to the availability of the energy sources in the territory, comparing city’s behaviour to a living organism dependents on the energy flow into and out. This one-to-one relationship between form and energy sources emphasizes mutations engender each other on their develop and decline. According to scientific studies, relevant “physical” factors affect directly settlement’s energy behavior and its microclimate. The ability of each city to work simultaneously on local and global objectives has driven Europe to indicate them as a crux and urban design as the appropriate tool for defining the shape compatible with sustainability goals. The use of this tool becomes prerogative to bear on urban form and reach the condition of self-sustainable energy’s island.