The Grands Moulins de Pantin

The imposing silhouette of Grands Moulins de Pantin (the large Pantin windmills) dominates the East Paris cityscape between Porte de la Villette and Porte de Pantin. Their neo-regional architecture with its three towers is a powerful symbol of the industrial past of the Ourcq Canal. This heritage will be protected when the entire sited is modernized to develop a service-sector complex over 50,000 sq m in area. Contemporary buildings will be used to rebuild the site's North and East sides, forming a coherent whole with the silos and the old windmill. This project is part of the quarter's large-scale redevelopment plan. The link between the past and modernity will be retained in each section of the site, not through an obsessive desire for preservation but in order to retain each historical period of the place.

The great Pantin windmills are one of the last symbols of the extensive industrial activity in the city's past, and remain in the forefront of the imagination of Parisians. Their silhouette, which took shape in the 20th century, rises on the horizon and stands as an emblem transcending the initial purpose of the buildings. Beyond preserving the most characteristic built sections forming the site's urban silhouette, our work is centred around two principles: - horizontally projecting the new buildings with a view to preserving and enhancing the two main existing parts of the buildings; - projecting in cross section and elevation these same new buildings (stratification and composition principle) according to their height and to how imposing they seem in the setting. The preserved parts include the “grand moulin” (the great windmill, which comprises the flour store, the silos and the old boiler room, at the eastern boundary of the plot) and the “petit moulin” (the small windmill, the central building, which was originally a windmill). In addition to these two building shells there are the two existing footbridges, and the slender transporter bridge that protrudes towards the canal. The reconstructed complex is articulated around a main axis, designed as a wide indoor street linking Rue du Débarcadère and the small windmill. There is a central concourse level with the latter, a veritable unitary area lined with the façades of the new buildings and with the renovated ones of the old buildings, providing foot access to all the entrance halls and car parks.

Its design echoes the significant architectonic elements of the original (rails, paving stones, etc.) associated with new compositional elements (vegetation, the downward slope and relief of the ground, street furniture, etc.), thus forming wooded and protected pedestrian areas. (In the same spirit a central delivery yard on level G-1 is formed so as not to detract from the pedestrian areas between the buildings.) The new buildings, which are relatively deep, are organized around concourses arranged either as interior covered atriums or as open outdoor patios. Situated either side of the indoor street, their upper sections are reached by two slender and fully glazed walkways. Each of the concourses gives the working areas their character and forms a compositional link with all the offices and buildings. Brick is evidently the material that now characterizes the complex. We have strived to show it off in the preserved buildings and use it for the newly-built parts, transposed in a contemporary finish. In the old buildings, the piers are renovated and form aesthetically plain pillars recalling the initial composition. The apron walls and bay windows are finished with metal and glass panels. In the new buildings, the proportions of the in-fills and the bay windows are reversed. The façades are mostly glazed and highlighted at ground level by opaque band courses covered with terracotta panels. They are punctuated by alternating modular frames and opening sections standing out from the fixed sections. The boiler room, which was one of the site's important industrial features, now preserved and showcased at the heart of this office complex, is one of the emblematic features epitomizing the site's industrial past. This boiler room, which used to generate electricity for the entire site, is more than a utility. It sits imposingly at the heart of a building designed around its original function, which we wanted to preserve. Indeed we felt that the quality of the space around this utility was fully transposable and capable of going through the ages while adapting to other uses. In this characteristic place we have thus constructed one of the project's showcase areas: the large atrium.

An emblematic industrial heritage site in the northeast of Paris with a remarkable silhouette when viewed from the Paris ring road. Now in the hands of BNP Paribas Group, this former flour mill closed down in 2001. A successful large-scale conversion which was completed after nearly four years of construction.

The winning architectural office of the 2001 competition, Reichen Robert & Associés, took on the challenge of converting the nineteenthcentury industrial site ‘Grands Moulins de Pantin’ into a 50,000 square-metre office complex which would meet the French HQE label (High Environmental Quality label), a national objective for sustainable building aiming at the improvement of the environmental quality of new and existing buildings. Environmental aspects must be integrated into every step of the process, including planning, designing, construction and management. The Grands Moulins project was granted the label for the design and the implementation phase. Around 22,000 square metres of the project involved the refurbishment of several retained old buildings. Although it was neither classified nor listed as a historic building, certain elements of the site’s industrial heritage had to be preserved, as Bernard Reichen explains. ‘We had a clear idea: we needed to find a way to bring the building back to life in the context of a new activity. To this end we preserved all the main architectural structures, the ones that defined the site’s image.’

Concept The design was therefore based on the principle of retaining the two oldest buildings, referred to the architects as the small mill and the large mill, as well as the famous transporter bridge, which has today found a new function as an exhibition venue. Through the company Seralu, these three refurbished buildings have been fitted with Reynaers aluminium systems (CW 86-EF/VEC, CW 50-FV and XS 50-VEC) in existing frames, with new openings, curtain walls and inner façades overlooking the atrium. Three new buildings and two footbridges on two levels, the latter equipped with Reynaers door and window systems CW 50-FV, have been incorporated so that the entire complex is interlinked without the need to go outside. This ensures a very high level of security and comfort to users of this miniature town which operates 24 hours a day. The buildings house the main departments of the company BNP Securities Services, known as BP2S, a subsidiary of the BNP Paribas group, which specialises in asset management and is European leader in its sector.

The balance between rehabilitation and new construction The painstaking work of this project required the interior of the buildings to be stripped, emptying them of their silos and machinery, rebuilding new floors and in many cases lining the façades. The three tall buildings and their mansard roofs were retained. Two silos were demolished, and the third called the large mill which overlooked the canal was refurbished. Its tall concrete structure faced with small red bricks was pierced with new windows fitted with Reynaers XS 50-VEC sections. The demolished 1950s semolina processing plant was replaced by a new simple three-storey building. Brick, the characteristic material of the complex, has been used to advantage in both the conserved and new buildings. Thus the newly sleek mills have retained their tall silhouette, and the boiler room made of refractory bricks and the former machine room remain visible in the middle of the building that has been opened up with glass.

Outcome Maximum use of natural light, which is part of the HQE environmental approach, creates a genuinely pleasant atmosphere in the office floors. Their finest feature is without a doubt the atrium formed in what was once the boiler room of the large mill, an open space fitted with Reynaers sections, revolving around the original boiler. Before it closed down, some 450 staff worked in the flour mill. Today the site is highly secured and contains 3200 work stations, 800 parking spaces and two staff restaurants capable of seating 2200 diners and supplied by a central kitchen. The site no longer stores sacks of wheat but instead houses financial services and their trading rooms, provided with the ultimate in information technology in this sector. There are even those who see in this a continuation of the story of ‘wheat’ (blé being Parisian slang for money).