Poste Source Gramont | Benoît Martres

To anticipate demographic growth in the Toulouse conurbation, Enedis and RTE have invested in the construction of a new source substation in the northeast of the metropolis. The substation plans to supply electricity to 35,000 to 40,000 customers, individuals and businesses, by transforming high voltage electricity (225,000 volts) into medium voltage (20,000 volts).

The site being less than 500m from the “Château de Thégra”, listed as a Historic Monument, the project was carried out under the vigilance of the “Bâtiments de France”. According to the urban, architectural and landscape specifications of the area, the project had to be composed of a maximum of two buildings provided that they were integrated into a common roof or facade treatment.

The project thus presents a common facade, to make the link and the continuity between the different elements of the project. The whole is made up of two volumes, separated by a heavy track, with an envelope on the outer facade which groups them together and unites them in the same architectural style, creating the feeling of a single whole. The difference in height of the two buildings gives the possibility of playing on transparency and lightening the built whole.

For the choice of materials, the main concern of the AMM Architecture Agency was to meet the practical and technical demand for this type of building, particularly in terms of mechanical resistance, earthing, fire regulations and acoustic regulations.

The objective was to reduce the use of different materials in order to highlight the simplicity of the volumes and the materiality of the project. It is thus entirely made of concrete: for the buildings, prefabricated concrete walls and for the envelope, prefabricated panels perforated in ultra-high performance fiber-reinforced concrete. The UHPC makes it possible to create very thin, very perforated, quality cladding, while using its durability and solidity, properties that are particularly important for this type of technical building.

To amplify this overall idea, the envelope is in white concrete and the buildings behind in dark gray tinted concrete. This color distinction also brings out the games of transparency and volumes behind the envelope. In reference to the traditional material of the Toulouse region, the wall is perforated with rectangles the size of a brick. To play on transparency, volume games and give the feeling of dematerialization, the wall is more or less hollowed out of these rectangles depending on the area. They are sometimes completely hollow and sometimes only hollowed out on 2cm. This is the case for the part of the fence and the facade which are in direct contact with the public space. To avoid the possibility that these openings favor an ascent and access to this particularly risky site, these brick imprints are not completely hollow over the first 2.6m.