The Kalasatama Electricity Substation serves the rapidly developing Kalasatama area situated close to downtown Helsinki. It consists of two buildings housing transformers and a switchgear building, all in concrete and clad over by an aluminium graffiti fence and an architectural steel mesh.
The location is a central, urban site between the former Suvilahti power station that has been transformed into a cultural centre, and the still-functional Hanasaari power station. The site is located by one of main traffic arteries leading to the city centre. The area is under a major transformation and the current, partially unfinished conditions of the immediate surroundings will change in the future.
The former power plant located next to our site was designed by architect Selim A. Lindqvist and it was taken into operation in 1909. A pioneering work, it was the first building in Finland to be built of reinforced concrete. Over time several additional buildings and pieces of process equipment were built on the power station site, and the still remaining structures are now protected. After the complex was turned into a cultural centre in the late 00s, it has housed spaces for artists, galleries, restaurants and more. It functions also as a venue for large events like music festivals and similar happenings.
Street art is a major, popular phenomenon in the area. The city of Helsinki has provided places and structures for graffiti artists to work on in Suvilahti since 2009. Continuation and enhancement of this scene was a request from the city as we began to design the building. It was also an opportunity for the building to provide a public function, which is not typical of an electricity substation. Because of this a graffiti fence was incorporated into the project.
The original assignment given to us by the client was to propose a location for the project site to the city master planning office, and to find an architectural solution that would make the project acceptable in that proposed location. The context set high standards for the quality of architecture.
The building programme has been laid out so that the whole relates to the scale and positioning of the existing, protected buildings. The building heights were restricted to a minimum and correspond to the scale of the context as well. The materials and structures are a reference to the existing, impressive concrete and steel structures on the site.
In-situ concrete facades are not common in Finland, mainly due to the unpredictability of the method, and also because of the amount of work and care it requires in both design and construction phases. In this project the concrete facades were executed successfully, which was made possible by a close co-operation between us, the contractor, the mold supplier and the concrete producer.
Due to our client’s security concerns, the concrete boxes are set back from the site limits. However, we did not want to create an ordinary industrial project in which the buildings are tucked behind a perimeter fence, because the site is in such a central location in the city. Instead, a 1400 mm deep metal double facade was designed to meet the client’s requirements and also to bring the building facades to the site limits in an urban fashion.
The metal claddings are cantilevered from the in-situ concrete facades by a black-painted steel frame. Dozens of medium-voltage cables connect to the concrete buildings underground and it was important to facilitate their installation and future maintenance by avoiding any intruding underground structures. On the north-eastern part of the site the graffiti fence is built on concrete foundations, as there are no such limitations in that area.
The woven stainless steel mesh type was chosen because of the depth and materiality of the material compared to more ephemeral types of meshes. The mesh reacts to ambient light in different ways and the outlook of the building changes due to the position of the sun, viewing distance and the effects of the weather. The shadows cast by the metal structures create changing patterns on the concrete surfaces. The slightly abstract, low contrast visual effect given by the stainless steel mesh above the fence functions as a neutral blank background for the graffiti.
The graffiti fence is about three metres high and consists of interlocking aluminium hollow- core profiles that were designed by us and custom-built for the project. The interlocking ensures rigidity and also stops the paint fumes from entering inside the fence which was a client request. The aluminium parts were anodised to provide a durable base finish. The graffiti fence needs to be cleaned occasionally when the thickness of the applied layers of paint starts to make painting more difficult. Visual connection on and through the site was done by using perpendicularly arranged vertical, anodised flat aluminium bars on the middle section of the north-eastern part of the fence and on the gate. The gate is also specifically designed for the project and it is cantilevered from the concrete walls.
The graffiti fence has turned out to be popular with street artists. New pieces are created over existing ones constantly and the art is communicated to a wider audience through social media channels. Through this non-stop activity of erasing and creating the building looks different every day.