La dimensione sotterranea della città: funzionalità e smartness del progetto urbanistico

The city is facing serious problems due to the unsustainability of its form and its impact on the environment; the underground city is thus an interesting approach to building a sustainable city. To consider the third dimension under our feet means to imagine a future where it is possible to transfer functions and activities, thereby improving the environmental balance of urban structures. Not all the cities are in a position to benefit from this possibility, but new possibilities exist and new urban structures are within man’s reach. In major cities, it is an important consideration for urban planning, because the underground is an important resource and using it could have considerable onsequences on urban performance. The utilization of underground space is an opportunity to develop new meaning in the planning process, which should be open to every opportunity that exists within the urban scenario, but also careful to ensure sustainability in building the urban space. Mobility, commerce, ogistics, leisure are some of the functions that could be transferred to the underground spaces, to enrich and develop new possibilities for the city. This paper analyses some of the primary factors in the building of urban underground spaces, identifying another way to enrich the concept of smart (or intelligent) city. In fact, if we think that a smart city is where innovation and urban vitality are concentrated, we could say that underground spaces can also contribute actively to this new image of the city.