From the end of the 1960s onwards, Chaussée de la Hulpe/Terhulpsesteenweg and Boulevard du Souverain/Vorstlaan were taken over by new office buildings, creating completely monofunctional areas devoid of any urban character on the edge of the Sonian Forest and the surrounding neighbourhoods. Today, projects to convert these offices are attempting to reverse past mistakes by proposing mixed-use programmes that are convincing in terms of their architectural quality, while not earmarking the buildings for any particular social purpose. From the CBR building to the Royale Belge, this tour looks back at the history of these office buildings and addresses the issues surrounding their conversion.