The potential for urban underground development remains mostly unexploited and underestimated in urban areas. Several reasons account to this, including a lack of knowledge of the urban underground. Additionally, multiple uses of the underground are still out of the practice.
Since underground infrastructures have no surface expression, the underground lacks opportunities for building architecture, and consequently it suffers from a poor public perception; most people do not like to go underground. The result of this poor perception of the underground by public and professionals is that it remains mostly dedicated to utilities such as transportation, underground car parks or for storage.
PHYSIOLOGICAL AND PSYCHOLOGICAL ASPECTS
The subterraneanenvironmentis often perceived as a site of unforeseen threat, secrecy, and risk. The vision of solid ground beneath our feet is thought of an inter-tangled network of cavernous tubes, abandoned subway tunnels, graves, and infrastructural cavities that fills us with ambivalence and fear.
One of the important potential hindering factors for underground space utilization is psychological aspects, and generally negative perception of these spaces. Many realized underground projects, namely subways, resulted in poor satisfaction of these psychological aspects
Many of the problems associated with living in underground habitats are not only technological ones, but rather are related to the degree of social acceptance of the concept and to the individual’s perception of the underground space.
Some of the issues facing humans above ground can be extrapolated and expected to have an impact, albeit to a higher degree of severity, while living underground. To name a few, claustrophobia, light sensitivity, general fatigue, eye fatigue, disturbance of circadian rhythms, insomnia, headaches, etc. These are just some of the potential ailments and stressors for which very little is known due to lack of experimental or real data.
Functional aspects are the functional requirements for an underground, internal connections of the spaces and efficiency of movement. Psychological aspects are all aspects that are related to the user’s experience of a space beginning with public safety on one side and comfort on the other side. In this sense, one can talk about soft building qualities.
Structural aspects include the overall quality of the construction including its flexibility and possibility to change. In other words, the main technical requirement of a structure is sustainability. A sustainable structure is a construction that allows greater spatial flexibility over a longer period of time and its infill is recyclable and reusable in the long run. For example, having an infill separable from the support structure increases the spatial flexibility by providing an option to place different functions.