Alternative use of rock caverns in Norway

In Norway you will in 2013 find 258 underground hydropower plants. Thus, telling a story of high activity and engineering expertise in this particular field.Power houses, in some cases, with spans measuring 20 metres and more. However, involved engineers and architects transformed them into spectacular rooms in colour, light and architectural design.

This variety led to the idea of using the same technology for sport halls and swimming pools needed around in the country. Over the years many such facilities have been finished.

We will make a round trip, throughout the country, from south to north, to give you some ideas of the variation in the use of rock caverns for such purposes.

Hydro power plants showed the way

The picture shows the Tonstad Hydro power Plant in Sira, a municipality in the south western part of Norway. This is one of many, showing engineering and internal architecture of high class despite being underground.

It is easy to understand that this gave the idea of putting sport halls and other recreational facilities, in rock caverns. The technique concerning geology, a variety of engineering, contracting and architectural design, was easily transferred to this new area.

The Oslo region

Oslo is the capital of Norway, situated in the south east part of the country. In this region there are seven sport facilities in rock. Three are rather large for international hand ball play, two of them includes also swimming pools. Four are smaller with activities including tennis, bowling, shooting, cinema, wrestling and others.

Pictures on the next pages illustrate these ideas.



Vassøyholtetis a facility inside a small hill situated in the municipality Skedsmo east of Oslo. Besides the bowling alley and shooting range there is also a cafeteria and gymnasium hall. Finished in 1979. The facility has a volume of 5.500 cub.m.


Sport hall

Holmenhallen issituated in Asker west of Oslo. This facility includes the following: 

main hall, 25x50 m, which is standard for hand ball, rooms for cinema/theatre, clubrooms and locker rooms and showers. It was finished in 1981 and has a large volume of

35.000 cub m.

Holmlia Sport Hall and Swimming Pool in rock

This facility is situated in the south part of the capital Oslo. It is a large installation including a sport hall for different kinds of ball games, swimming pool, 20 x 37 m. both with all necessary facilities for locker rooms, showers and saunas, fitness centre, clubrooms, etc. This large facility serves the part of the City, the Holmlia region, with 10.000 inhabitants. It has been in successful use since 1984 and has a usable volume of 53.000 cub.m.

Holmlia Sport Hall. In active use since 1984. Foto:Trond Joelsen, Byggeindustrien October 2013

Holmlia in Oslo. Swimming Pool, 6 lanes, 25 m. Foto:Trond Joelsen, Byggeindustrien October 2013

Gjøvik Olympic Mountain Hall

The town of Gjøvik is situated at the west bank of Norway’s largest lake, Mjøsa in eastern Norway. The use of underground facilities began at an early stage in 1975 by building a swimming pool in rock, in the middle of the town. The experience in use, operation and maintenance, were main factors when it was decided to build a huge ice-hockey arena in the same rock for the Winter Olympic Games in 1994.

The main hall measures W: 61 m, L: 91 m, H: 25 m. Volume: 141.000 cub.m.

The drawing shows the entrance tunnel to the right entering the lobby/restaurant area with the old swimming pool to the left and the huge new ice hockey arena in front

Foto: Ådne Homleid, Byggeindustrien,Oct. 2013

Gjøvik Swimming Pool in rock. 6 lanes of 25 m. W: 20 m. Was commended the Eurostructpress Award for Architecture in 1980. In active use since 1975.

Gjøvik Olympic Mountain Hallis the largest facility in rock for public use so far in the world. Picture above showing the great moment 6th of May 1993:  The opening ceremony with the King and Queen of Norway with 5.800 invited guests participating. The construction work was finished 3 month ahead of schedule. Volume: 141.000 cub.m.

From an ecological perspective, this hall was the most innovative of all the 1994 Olympic Games Arenas. The naturally stable year-round temperature inside the rock has reduced the halls heating/cooling cost by half, compared with conventional halls. Since the hall occupies no surface area- located as it is “under” the centre of Gjøvik- no trees had to be felled and no new infrastructure had to be built.

Since the Olympic Games in 1994 it has been in extensive use all year around with excellent result, both for sport activities and exhibitions as well as several other purposes.


We are moving north and west in the country, to the industrial town Odda. The town is situated in the south part of Sørfjorden (South fjord) in Hardanger. Steep mountains surround the town. Lack of suitable building ground for their new planned sport hall brought up the idea of a new facility in rock W: 25m, L: 50m, H: 13m. Finished in 1972. Volume: 27.000 cub.m

The entrance buildingto the left, is situated close to the outdoor sport field. A tunnel to the right leads to a 110 m sprint track and shooting range and club rooms.  A tunnel to the left leads through locker rooms and showers to the main hall.

After more than 40 years extensive use, the owner reports that Odda sport hall has been the “flagship” facility for the town. Activities like biathlon (shooting), fitness center, running, jumping, gymnastics, handball, football, volleyball and ski shooting are still going on around the clock.

Running and maintenance cost has been relatively small.

Oasen Bathing and Recreational Facility in rock

We have reached Mid-Norway and entering Namsos, a town situated in the north part of Trondheimsfjorden, which has a spectacular facility all inside rock. The main pool has 8 lanes 50 m long and there is a 5 m high diving tower, a pool, saunas, a 25 m long water “rollercoaster”, a restaurant and other facilities. The facility was finished in 1988.     

Oasen, diving towers

“Oasen” bathing and recreational facility in rock, Namsos municipality.Volume: 27.000 cub.m.

”Oasen”: Bading, swimming, diving and dining in rock


Now we are moving far north to the fishing town Svolvær in Nordland. A rather small hill in the middle of the town was chosen as site for a standard hall for handball. (25 x 40 m.) The facility includes also lockers and showers, a shooting range and clubrooms. The most interesting thing is the optimal use of the hill as shown on the drawing below. Finished 1983. Volume: 21.100 cub.m.


Prestvegen Sport Hall in rock, Kirkenes

Far north in northern Norway, in the town Kirkenes, ends our journey. The picture below speaks for its self. The town is very proud of its rock facility!

Kirkenes: Sport hall in rock

Final remarks

The aim of this journey, visiting some of our sport facilities in rock, is to give you some ideas in how utilisation of rock caverns may be applied.

The long term experience for these facilities is very good.

An inquiry to the owners of ten facilities states the following:

  • The users are well satisfied with their facility and very often proud.
  • Both operational as well as maintenance cost are much lower in rock compared to an aboveground solution. Thus, the lifetime cost is much lower.
  • All users are satisfied with the combination as civil defence shelter.

If one decides to build a rock facility, one should have extra focus on:

  • Employees desire for daylight
  • Control of water leakage and humidity

In spite of the clear advantages with the rock cavern solution, the first choice for a new sport facility in Norway today, (2013) will be the aboveground solution. The main reason is that the government no longer pays for the civil defence shelter. The rock cavern solution will then normally be 10 to 20 % more costly for the municipality.

Since the rock cavern alternative also is a much better solution environmentally,  a proposal has been submitted to the government to subsidise the rock alternative.

Jan Anton Rygh, Norwegian Tunnelling Association