Valuing Sustainability Externalities of Urban Underground Space Use for Planning and Land Administration

Underground space (UUS) use is of great importance for sustainable urban development. However, it is far from persuasive to compare the descriptive values of UUS with the construction costs. The value of UUS use to urban sustainability shows both positive externalities and negative externalities. The lack of quantitative value analysis might result in a “radical” or “conservative” mode of UUS development. In this regard, the quantification of UUS value, particular the external value in monetary terms, will become the turning point in the planning and land administration process of UUS development. This short article gives a brief introduction of a series of studies that monetize and visualize the externalities of UUS use to urban sustainability based on the service replacement cost method while using UN 2030 Sustainable Development Goals (SDGs) as value metrics. The valuation results are utilized to establish a set of new approaches for sustainability-oriented UUS development strategies of planning evaluation and land price setting.