Disappearing act: Electrical substation extension in Lyons
Client: RTE, ERDF
Architect: rue royale architectes
Location: F–69002 Lyon
From the very outset the architects wanted to conceal the volume as soon as possible; in fact, they intend it to disappear completely behind a forest of bamboo over the years. An uncommon approach, one that requires knowledge of the substation's history to be understood. This was built in 1991, at a time when the plot consisted of wasteland, and it was only ten years later that plans were drawn up to use the area outside Lyons for housing. It was in this way that the building full of transformers came to be surrounded by social housing and blocks of freehold apartments and offices.
Rue Royale Architectes not only took on the task of adding a gas-insulated substation (GIS) and a distribution substation to the original building but also came up with a landscaping concept for the plot, which is surrounded on all sides by a ring of buildings. Moreover, the end of the long and slender substation that divides the site faces onto a street, plus the almost windowless original building has a fairly massive presence in the locality, despite being much lower – at a mere nine metres – than the neighbouring buildings. The architects thus continued one of the extensions at the same height and made the other three metres lower. The enclosure that now forms the perimeter around the substation facility is at the same height.
The first step was to create coherence by using similar colours. The existing building was given a black surface coating due to the specifications of the public utility firm that the structure of the original façade was to remain unchanged and costs be kept as low as possible. Wrapped in galvanised steel, the extensions harmonise in colour with the original building without imitating it, contributing to a uniform backdrop that can occasionally be glimpsed through the perimeter skin of stacked gabions. In some cases these wire-meshed boxes are empty, in others they are filled with blue limestone or plants, enclosing the building from two sides and helping conceal the austerity of the facades. Merely the three barrel roofs that lend the existing building its particular silhouette can be seen fully, but they too may soon be lost from sight, namely behind the forest of bamboo that has been established in the narrow strip between the building and the gabion fence. The decision to use bamboo was soon reached as the plants are extremely robust, plus they limit the need for maintenance. A flat roof planted with sedum rounds off the landscaping programme for the substation facility.
Initially there was a great deal of concern in the neighbourhood about the impact of the extensions, but guided tours open to the public and the bamboo screen managed to put these worries to rest. Moreover, the second skin has a positive environmental effect: apart from dispelling fears, it also shields the dark façades of the buildings from the sun, meaning less energy is required to cool the rooms.