Design recommendations for sustainable urban underground spaces

Considerable research has been devoted to sustainable urban underground space use, with the importance of urban underground spaces (UUS) for urban sustainability having been well documented. However, the focus of most research stems from an engineering or urban planning point of view, overlooking ways in which urban design can contribute to sustainable UUS. This paper aims to synthesize and illustrate urban design recommendations for sustainable UUS in an integrative and holistic manner, taking elements identified by other disciplines into account and reinterpreting them from an urban design point of view. The findings allow us to suggest recommendations on livability, connectivity, temporality and interdependency. By renewing the focus on urban design and making the recommendations explicit, the complexity of the subsurface is acknowledged. This means designers will become better able to master this complexity and thus design more examples of good practice and further enhance the added value of the subsurface for sustainable cities.