Oslo is the capital of Norway. A small town by global standards, but still a rapidly growing city. The population of Oslo is the fastest growing in Europe, a tendency giving both challenges and opportunities. The city will require large investments in communication systems, new dwellings and a integrated land use and transportation planning. Underground space is already widely used for transportation, storage, extraction of heat and for foundations of buildings and infrastructure, due to the rapid growth of the city the underground use is expected to develop rapidly. The city of Oslo deals with geological challenges such as deep horizons of clay, often containing a large amount of organic matter, alum shale’s that contains enhanced levels of radium and uranium, and quick clays.

Read more about Oslo City in case study report TU1206-WG1-012


Although the oldest registered settlements in the region dates back to around 11000 BC, the city of Oslo was only founded around year 1000. The oldest part of the city was located in the eastern part of Bjørvika – at the foot of the green hill called Ekeberg. During the middle ages, the town developed into one of the most important centers of trade and commerce in Norway.

Oslo thrived until the disastrous fire of 1624, which reduced much of the city to ashes. The fire gave rise to the establishment of the new town at the opposite side of the Bjørvika bay, on the north side of Akershus castle and fortress[1].  The new town, named Christiania after King Christian IV of Denmark and Norway, was built on a grid plan in the typical European fashion. As a consequence of the great city fire, a ban on wooden houses was introduced in Christiania, allowing only solid brick, and half-timbered brick houses, a map over these can be seen in Figure 4.  Still, many of the buildings had wooden cores, constructed in the traditional Norwegian manner using logs. At the time of the first official census in 1769, Christiania had 7469 inhabitants.

City facts

  • Founded:  Year 1000
  • Size: 453,7 km2
  • Urban area: 150 km2
  • The approximately 300 km2  is the so called “Oslomarka” a forested recreational area protected against urban development by Norwegian law.
  • Population 625 000
  • Administration: The City Council has 59 members, headed by the Mayor of Oslo. Elections are held every four years.

Underground use:

  • Railroad tunnels
  • Metro tunnels
  • Road tunnels
  • Waste water tunnels
  • Cables
  • Foundations
  • Storage
  • Energy wells for heating and cooling

 Underground challenges:

  • Settling
  • Deep clay horizons
  • Deep clay horizons with high content of organic matter
  • Quick clay
  • Radioactive Alum shale
  • Groundwater changes
  • Rapid development of underground use
  • No control of where or how deep new energy wells are drilled