[2][3] Victor Horta was commissioned by the Belgian Workers' Party (POB/BWP) to build a grandiose people's house on the Place Emile Vandervelde/Emile Vanderveldeplein, in the Sablon/Zavel district of Brussels.

In spite of a rather restrictive and irregular plot, along a circular square and on a slope, Horta succeeded in constructing a four-storey building with maximum functionality.

[4][5] Unlike Horta's houses, the decoration was kept to a minimum, as it was a purely functional building, mainly constructed in white cast iron (more than 600,000 kg [1,300,000 lb]) with curtain walls.

The only strikingly recognisable Art Nouveau features of the façade were the balustrades with curling lines, as well as a slight curving of the steel pillars supporting the roof.

On the roof, the building was decorated with signs bearing the names of people who contributed to the socialist cause, such as Karl Marx and Leon Blum.