Entretenir le projet moderne

The term ‘maintenance’ has a dual meaning: that of upkeep and care on the one hand, and that of discussion and dialogue on the other. These two aspects are fundamental to the work of the team of architects and urban planners at the Karbon' cooperative. The team was formed when the post-modern movement, which was dominant in Brussels at the end of the 2000s, began to decline, with the idea that architectural form could find a deep cultural meaning not in aesthetic discourse, but in a reflection on the sobriety of the act of building. This means a relationship with the social and physical context over a long period of time, in construction traditions, in a constant concern for the history of the territory, the construction techniques, the origin and integrity of the materials, and finally, the quality of the working conditions of the builders on the site. It implies a patient work of recognition and description of the resources present – material, spatial, social and historical. Architecture can therefore be defined as the organisation of space, that is to say the measurement and regulation of the spacing, rhythms, surfaces, volumes and uses of these resources. And it is in the work of description that, for us, the heritage and cultural value of a creation lies. Indeed, to describe and to know also means to become attached, in the sense that Thierry Bonnot⁴ understands it: to give meaning to something so that it becomes an object, the object of specific attention and intention. The meaning that the building takes on is revealed by the nexus of social relations, construction cultures and stories inherent in its evolution.

This relationship with time is not only retrospective. Reflection on the act of building addresses the broader issue of sustainability. It is a question of seeing sustainability less as a quest to limit the environmental impact of construction and the practices that a space induces, and more as a relationship with time. Thinking about architecture through the prism of duration implies, as the philosopher Pierre Caille⁵ suggests, approaching architecture through the idea of maintenance.

Maintaining the spirit of the project. A critical approach to specifications

The maintenance of the modern project can be considered as the maintenance of its spirit. Modernist architecture reflects clear ambitions, centred on the idea of equal quality for each home in a building or neighbourhood. This explains the often rather austere rigour of the design and the radically serial aspect of the buildings, repeating the same housing module, the same chassis design and the same balcony detail. In the case of social housing renovation projects, maintenance is mainly carried out through a critical reading of the specifications of the order, and translates into a desire to optimise the existing structure in relation to the changes to be made, which are generally mainly related to thermal insulation and the adaptation of the homes to current housing code standards.

The issue of neighbourhood quality is central to the housing block on the corner of Chaussée de Boitsfort and Rue Ernotte. The six-storey building, with 59 apartments, was designed in 1976 by the architect Michel Barbier. It stands freely in a group of apartment buildings like many others which, through their open character, have built up the space of the Brussels Green Belt. But this parc is in reality a double illusion. Firstly, it is cadastrally divided between several owners, and therefore different managers. Secondly, the main quality of this type of housing block, its small footprint, is only relative because it is built on one or more levels of a larger underground car park. Also, while the contract in 2020 focused on the energy renovation of the building and a densification of the site, the approach was to consume no land in the park and to build only on the parking area exceeding the size of the housing block. The building thus gains mainly in width, with the addition of two bays on each gable wall, while the continuous glass-fronted balconies are replaced by a lightweight steel structure where terraces alternate with housing extensions, built, as at Tornooiveld, in CLT and a timber frame with blown insulation, according to a rhythm and aesthetic that echoes the elegant steel tie rods that until now have punctuated the facades. With another series of rooms surrounding the technical space on the roof, the number of housing units increases by seven, but it is above all the increase of a total of 51 rooms that is remarkable with this operation, in an urban region that singularly lacks large family housing. 

Maintaining the look. Starting from what is already there

Modernist social housing buildings form a heritage that is still too rarely recognised for its intrinsic social and urban qualities. Maintaining these qualities requires a detailed analysis of what this heritage has to offer, an analysis that must be carried out with as open an approach as possible.

With its 380 flats, the Goujons tower in Anderlecht is the largest flat building in the Brussels Region. Built in as part of the policy to renew the urban fabric of Cureghem, led by the municipality of Anderlecht from the end of the 1950s, it was to form part, like the tower in Rue Van Hoegaerde in Koekelberg, of a larger group of tall buildings around the old port basin of Biestebroek. Its specific, slightly folded shape corresponds to the historic course of the Senne river, whose poor soil quality had to be avoided. Isolated and unique, the Goujons tower is now an important landmark in the metropolitan landscape, but it also embodies all the ills of modernist social housing: a concentration of social problems, cramped housing in an out-of-scale building, construction problems with premature ageing, and an architecture that, breaking with its environment, becomes the stigma of social precariousness.

In reality, the tower's flats are not that cramped, and their inhabitants are quite satisfied with them, were it not for the ageing of the facade and balconies, which have been inaccessible for several years. The older residents also remember that living in this tower was, in the 1970s, a source of pride and a real improvement in their quality of life.

The project here is complex. It involves carrying out an energy renovation with a fully occupied tower. The structure, with its thin concrete walls, does not allow for anchoring to suspend new terraces. It is therefore necessary to erect a new structure from the lower parking levels. This structure is treated like a mesh, with the bands of the new terraces alternately anchoring themselves in the intrados and extrados of the pilasters, the spacing decreasing with each floor until they align with the roof line. These same bands thicken in parallel with the height, to form a complete guardrail on the upper floors. This dual graphic effect generates a difference in perception from the foot of the tower, where the architecture presents a strong and very open modinature, while from a distance, in the landscape, it asserts itself as a simple and strong form.

The approach is clinical. A single material, sand-coloured architectural concrete, which serves as both the structure and the finish for all surfaces, a progressive montage that serves as scaffolding for the gradual insulation of the facade and the replacement of the chassis in front of the existing joinery, which serves as a construction site partition. And, when the upper floor is finished, the old chassis are removed and the living spaces are screeded in just three half-days (one visit for dismantling, one for cladding and one for painting).

Both a metropolitan landmark and a living space with a generous outdoor area, the renovated Goujons tower revives the progressive image it conveyed when it was built. But the project also raises the question of the scale of intervention in a renovation, of what the building, already there, teaches us and what meaning it gives to the act of transformation.

Although spectacular, the renovation work on the Goujons tower pursues a quest for a minimalist approach in contemporary intervention to upgrade the comfort of housing. A minimal act from the point of view of compositional methodology, that of the search for the minimum intervention to move from architectonics – the assembly of constructive elements – to architecture. 

The building of the former housing complex for married gendarmes, located next to the former gendarmerie barracks in Ixelles, on Boulevard Général Jacques, is a magnificent example of the modern classicism favoured by the public authorities in the post-war period. The stone facade, incorporating a war memorial, excludes any external insulation. The project is based on a precise survey of everything that gives the building its value: the parquet floors, the windowsills, the radiators, the window frames, the kitchen furniture and the built-in cupboards. These elements, which are of a ‘light’ nature, in terms of finish, are preserved, restored or moved to other places in the buildings, such as light fixtures, kitchen tiles recovered from the bathrooms, etc., with the work focusing more on a few ‘hard’ elements, such as the walls separating the living room from the entrance hall and the kitchen and, above all, the technical ducts. In contrast, the climate of the housing is also addressed by transforming the courtyard into a garden, integrated more broadly into the treatment of rainwater, while the facade walls are insulated, from the inside, with expanded cork panels.

This notion is perfectly embodied in the renovation of Victor Bourgeois’ Cité Moderne in Berchem Sainte-Agathe. According to his adage “Architecture is misery”, Victor Bourgeois sought to design a neutral architecture that, in its banality, was intended to salvage the architectural composition and the integration into the landscape of the city. What does this architecture have to offer if we remove the few attributes that make up its identity, such as the joinery, the specific thickness of the roof or the highly structured rendering of the facade? The aim was therefore to rely as much as possible on the characteristics of the buildings. Firstly, by respecting their structure. The uses of the rooms are reviewed with very little modification to the plan, the interior joinery is reused, while the floors are raised, which benefits the installation of technical equipment and makes it possible to reduce, without modifying the bays, the height of the spandrels, which were too high compared to contemporary expectations.

 Then, the study of fly ash concrete, used experimentally in 1922 for the walls, showed that its cavernous structure gives it slightly insulating properties. By supplementing them with blocks of hemp mixed with lime, it is possible to create a solid, collaborative and breathable wall complex. This technique is the result of extensive research on several construction sites, which has gradually made it possible to use bio-based materials in public contracts for the renovation of social housing.

 The renovation of the Cité Moderne will take place over many years. The advantage of this is that we can proceed by trial and error and make successive corrections, which allow us to gradually refine our approaches and sharpen our focus on what the building and its space have to offer for optimal comfort today.

 This empathetic approach makes it possible to question the scope of a renovation and gauge its validity in a search for the optimum between performance and the investment required to achieve it. The grey energy of the construction site is often underestimated in the overall performance of a building.

The project as maintenance.

 The practice of the modernist social housing renovation project has forged a long-term approach, seen as a research process, as a construction of meaning for the act of transforming and building, more than by the search for an attitude for an aesthetic reconfiguration, supposedly necessary, of the existing architecture. The diversity of experiences – from the extension of housing to the simple improvement of the existing structure, including work on the envelope – is part of a continuous approach, based on a detailed understanding of the characteristics of the buildings and seeking above all to pursue and maintain the spirit of the modern project, in its technical, aesthetic, social and emancipatory aspects of social housing.

What we wanted to demonstrate here was an approach to the paradox that characterises the issue of social housing renovation. The discourse on sustainability has ‘sustainably’ — the word is used deliberately — legitimised the notion of planned degeneration: it is considered obvious — there is no debate about it — that it is necessary to rebuild or heavily renovate, in a ‘more sustainable’ way. However, this patient work of open-mindedness and maintaining curiosity about the existing, whatever it may be, shifts the focus of the architect's work from designing new spatialities to match a stock of buildings to the demands of the future, to a role of maintaining a building considered as a heritage. This shift is part of a movement that is gaining particular momentum in Brussels, and is contributing to its influence on the international architecture scene, integrating circularity and, more broadly, the maintenance of what is already there, not as a goal, but as a working method, as a cultural foundation for architectural design. 

[1] Gery Leloutre, « La Bruxellisation: Phénomène urbain autant que jalon historique », Septentrion 5, no 1 (2023): 74‑80.

[2] André Barey, Déclaration de Bruxelles (Bruxelles: Archives d’architecture Moderne, 1980).

[3] Julie Neuwels, L’architecture (durable) comme technologie de gouvernement : apports et détournements de la sociologie de l’action publique. CLARA Architecture/Recherche, 3, 63-72 (2015) 

[4] Thierry Bonnot, L’attachement aux choses, Le passé recomposé (Paris: CNRS, 2014).

[5] Pierre Caille, Durer. Eléments pour la transformation du système productif (Paris: Les Belles Lettres, 2020).