An introduction to the development for urban underground space in Helsinki

Helsinki has developed a dedicated Underground Master Plan for its whole municipal area, not only for certain parts of the city. This work began in the 1980s and from then the City of Helsinki has maintained an underground space allocation plan. On average, under each 100 m² of surface area in Helsinki there is 1 m² of underground space. Consequently, there are still many underground resources for future needs existing within the whole city area. The Underground Master Plan of Helsinki shows both existing and future underground spaces and tunnels, as well as existing vital access links to the underground. It also includes rock resources reserved for the construction of as yet unnamed underground facilities. The development of the master plan has resulted from a long-term commitment of many public and private stakeholders to the planning process, the creation of a suitable legal framework and the collection and management of the data on geotechnical conditions and underground facilities.