During a very long period of time, civil engineers have been the only ones to be designated as the experts for underground space, while the planners and architects were the ones of the development at the surface. Cities worldwide tend to overlook an invaluable asset that lies beneath their surfaces. Most cities and urban regions are unaware of the benefits underground space use has to offer, both for climate inflicted and spatial constraints: In many cities, infrastructure development is being outpaced by population Growth. Climate change effects are requiring radical new approaches in terms of coping with for example excessive rainfall. The available space at the surface is rapidly being used up and the biggest danger is that built-up spaces are taking over the public green spaces of cities thereby threatening livability and quality of life. Urban underground space forms a societal asset, which is often unappreciated and underestimated in terms of the role it can play within dynamic city environments and associated challenges. The world-wide trend of increased urbanization creates problems for expanding and newly-developing cities alike. Population increase leads to an increased demand for reliable infrastructure, nowadays combined with a need for increased energy efficiency and a higher environmental awareness of the public. The use of underground space can help cities meet these increased demands while remaining compact, or find the space needed to include new functions in an existing city landscape. Use of Urban Underground Space (UUS) has been growing significantly in the world’s biggest and wealthiest cities. UUS has been long acknowledged to be important to the urban development agenda: sustainability, resilience, livability, and creating a better urban environment in particular.
