Designed to be one of the masterpiece of the 1958 International Exposition, the Cité Modèle of Heysel is one of the few progressive Belgian social housing complexes adhering to the CIAMs precepts. This type of urban development referred as “grand ensemble†is exceptional within the Belgian borders in particular due to the introverted character of the original plan. Indeed, the radical composition of the Cité Modèle clearly expresses the will to break away from the traditional urban fabric becoming a self–sufficient entity, protected from the “chaotic†existing city. Renaat Braem, emblematic figure of the Modern Movement, known as a part of the heterogeneous team of Belgian architects who designed the Cité Modèle, was convinced that the city, by its intimidating external monumentality and its inner serenity, would reorganize social relations and thus generate a new, more liberated human. Once considered as a virtue, this introverted aspect of the social housing design has a “ghetto†resonance today. After some golden years, it became place of relegation of vulnerable populations. In addition, the pilot city has been slashed by its infrastructure of collective social and by its individual housing units that originally had to balance the site density. In recent years, the choice made by the owner in order to face contemporary issues was to reopen the whole site to its environment while strengthening the architectural unity and the strong identity of the buildings. To achieve this, they hired Gilles Clément to rethink the landscape areas. This paper aims to question the legitimacy and sustainability of this built and landscape heritage but above all its continuity. The contribution is an opportunity to open a window on the Brussels’ current position to better understand the reception of Modernist era legacy, in general, and specifically the policies of intervention on the post–war housing heritage.