In the city of Solingen, in the Ruhr area of Southern Germany, the local observatory – in collaboration with the regional industrial heritage organization – have instigated a competition for the redevelopment of an old spherical gas container. The strong industrial character and historical context of the container should allow the new project to fit in with the local vernacular of high value industrial buildings.
The site is on the edge of a residential area near a railroad, from the rail station the top half of the steel sphere is visible. With a diameter of 26 meters the container has a frame of eleven columns that rest on 3m high concrete foundations.
The original design is pragmatic in its approach. A sphere was used as the most efficient model with the largest surface area available to function at the lowest cost. The staircase was built with the same functional consideration as the rest of the building and it follows that, to use the existing spherical structure, we would need to design with the same rigor.
Arguably a good design for this project should be contained within the existing structure; with an entrance to a back office, an entrance hall for 80 people, exhibition space with a planetarium and an observatory in the hemisphere to account for. At the base of the sphere we have cut an opening to fit within the foundation, this gives space to the entrance hall. On the other side of the foundation wall we have placed the offices, presentation rooms and other general amenities. These spaces open out on to a patio that provides light to an otherwise sheltered area of the project. We have sculpted the landscape to the height of the foundation wall in order to compliment the spherical profile. The entrance begins with a series of steps rising up through the void, on the first and second floors are two open exhibition floors. The third floor contains the planetarium and the observatory is located at the top of the sphere; here there is a second cut in the existing structure which allows the telescope to rotate without being obstructed. On top of the dome is an antenna with a laser to be used to give focus to the user.
The existing structure has been calculated to support its functions, however, we have added an additional exoskeleton structure which supports the structure from the outside (such as the prefix – ''exo''). There is also a steel tube in the center used as an elevator shaft which will help support the buildings new uses.