EWZ substation, Zurich-Oerlikon
Coloured concrete – under the earth
Zurich-Oerlikon is the location of the new ewz substation – a world first in energy supply. A new type of gas-isolated switchboard to be connected gradually to the supply area from September 2015 to 2018 makes a space-saving plant possible. This allowed innovative planning of the construction project in turn.
Milestones in the constructions of a grid base
As the new switchboards use less space than previous systems, the implementation of the construction allowed thoroughly new concepts to be considered. The new substation was thus built underground using high and medium voltage switchboards (170 kV to 24 kV). The transformers and switchboards are two floors below ground level. Only the rooms for the grid base staff are found above ground. The advantage of the overall concept is, with the space-saving new building and after demolition of the old plant, that the site in an excellent location in north Zurich can be returned to the city.
Apart from functionality, the building should also solve architectural challenges. Energy and benefits should be made visible for the customer. Thus two conceptional openings were planned for the structure: a showcase, through which the art installation “The captured flea” by artist Yves Netzhammer can be seen. At the other site, a large-format window front as tall as the building makes the exposed concrete supporting structures visible. The observer can look inside. where it becomes clear that this is no lump of concrete dumped on a green field, but an underground concrete building. The actual concrete façade is first seen in the entry area, but the majority is several meters under the earth.
Concrete plant with authentic look
The exposed concrete presents itself in a distinctive, typical panel structure. A colour concept turns the building into an attractive space. The building elements are kept in an intense orange hue. In contrast to this, the PSS specialists – Interservice AG – have given the exposed concrete surfaces a refined, green hue. Over 2,300 m2 of exposed concrete have been coloured with the faceal Colour concrete glaze in the RAL 6011 hue. This way they have not only been given a pigmentation which retains the characteristic optics and feel of exposed concrete, but also a surface treatment with oleo- and hydrophobic surface protection. The colourisation enhances the concrete’s original expressiveness and contributes to the appealing spatial atmosphere. In the above-ground part of the building, the exposed concrete has been treated with the transparent, high-performance waterproofing system faceal Oleo HD. Thus the exposed concrete is oil and grease-repellent and unchanged in appearance. Worth mentioning also is that the 3,000 m2 of exposed concrete was protected against staining during construction with PSS 20 construction phase protection. This is reversible and removed before the final treatment.