The basic notion underlying urban underground development is that underground space is a non-renewable resource, therefore planning its use must be done in a sustainable, environmentally-responsible manner with due account taken of economic, functional, social, and legal aspects. This paper addresses issues related to the planning, siting, design, construction, operation and maintenance of underground structures in the city of Moscow. The mechanism of the interaction between an underground structure and the surrounding rock masses is described. It is shown that underground engineering can be significantly enhanced through the use of expert systems. The paper also discusses the need for changes to the legal framework for the use of urban underground space.