The continuous growth of the population and the increasing demand of urbanization expansion towards the development of high-rise buildings.
To meet their energy demand, the European Community is trying to address the designers to nearly zero-energy buildings.
It is reasonably simple to produce a small residence totally energy efficient however it will be a real challenge to do the same for high-rise residential buildings.
In the general research of the “P\u3e 20” a building of more than 20 floors, equipped with renewable energy systems and with low impact technologies, with complete energy efficiency is studied energy self-sufficient. The first technology introduced in this paper will be the Pico Hydraulics system, a technology for the exploitation of hydroelectric potential of grey water to produce electricity. Finally, the economic, environmental and social advantages of P\u3e 20 is to be illustrated, for Albanian and European cities