The building industry is an economic key driver since its involvement in environmental impacts is strongly recognized: this sector is still one of the main responsible of GHG (Greenhouse gases as CO2, CH4, N2O, etc.) emissions, in particular buildings generate approximately 40% of the CO2 emissions, thus contributing in large measure to the global warming. At the same time, another relevant contribution is in waste generation: the building sector, indeed, is responsible for almost 35% of the total waste production. The dissertation is intended to introduce the Circular Economy practices through which it will be possible to apply the principles of sustainability: the implementation of Circular Business Models in the building process may lead to opportunities in economic, environment, business and society terms.