Neutelings Riedijk Architects makes a human-scale covered city in its huge converted freight station in Brussels with warm CLT and floor to ceiling glazing
In normal times, Gare Maritime would be teeming with activity now. Around 4000 people are expected to inhabit the workspaces in this remarkable reinvention of a vast, historic freight station in Brussels, which has been repurposed as a mixed-use destination full of public space.
Designed by Rotterdam practice Neutelings Riedijk Architects, the project has the distinction of being the largest cross laminated timber installation in Europe, with the CLT used to create 12 new ‘pavilions’ totalling 45,000m² in the former station.
It is also notable for its context as part of a regeneration of the wider surrounding area. Located by the city’s main port, the canal district was historically dedicated to the comings and goings of goods and to warehouses and associated industries. Built between 1902-08, Gare Maritime was at the heart of all this commerce. Once the largest station for goods in Europe, it was subsequently used as a train maintenance depot before falling out of use by the 1980s.
While much of the surrounding area was regenerated over the years as part of the renamed ‘Tour & Taxis’ district, the station had to bide its time. Now that the wait is over, it’s a shame it won’t be able to fully embrace its new uses until the Covid-19 crisis has subsided.
With the fabric of the heritage-listed building already restored by another design team, Neutelings Riedijk Architects’ concept provided the extensive architectural infrastructure for its re-purposing.
Measuring 280m long and 140m wide, the station provided 40,000m² floor space. Faced with such a vast space rising up to 24m at its tallest in the central main hall, the challenge was giving the required substantial new development a human scale while retaining a sense of the host building’s monumental space.
According to Neutelings Riedijk Architects project leader Dieter de Vos, the priority was evoking a sense of the city within the building through the addition of the pavilion workplaces to create a streetscape with aisles and open spaces conceived as streets and squares. These are positioned above flexible ground floors, which are envisaged for a variety of purposes including retail and restaurants. The hope is that this diversity will reflect that found in traditional cityscapes.
‘Because of the scale of the existing roof, we quite quickly started to think of making a covered city with smaller volumes that would create an urban fabric and with large and small streets, larger and smaller squares,’ he said. ‘It was the best way to deal with such an extraordinary building. For us, it was important that it felt like a proper urban environment and not too much like a mall.’
The new 4,500m² pavilions are positioned in parallel rows of five within the two side aisles of the station to the east and west, with the taller central hall in between left open as public/events space. Two smaller pavilions of 750m² each are positioned in the southern gable end of the station. The events space is flanked on both sides by 16m-wide green, walking boulevards inspired by the Ramblas of Barcelona. Within these is a series of 10 themed gardens, interspersed with squares lined with mosaics.
Client Extensa was keen that the new pavilions should follow circular building principles – sustainable measures already introduced as part of the works to the original building include 17,000m² of solar panels, geothermal energy and rainwater re-use.
CLT was the ideal structural solution, not only due to its sustainability credentials in terms of cement-use reduction, but because of its light weight compared to other options – the architect estimates that the building would have be five times heavier in concrete.
Concrete slabs on pile foundations support the pavilions, allowing them to be completely independent of the host building’s steel structure. Their demountable connections mean they can also be dismantled and removed without damage to the station structure if the interior structures need to be altered for another use in the future. Another important factor was the economical solution that a prefabricated CLT structure offered for such a large amount of construction, with no need for craning and a short assembly time minimising site disruption.
In addition, the look and feel of the wood offer a pleasing contrast with the steel, says De Vos, the pavilions creating a completely different internal environment to the expansiveness of the wide-open public areas.
Each new building has the same design. ‘We thought that uniformity would be most appropriate because the architecture of the existing station is quite rigorous, with the quality of its facade coming through the repetition of the bays,’ says De Vos.
Pavilions have a ground and first floor overlooking the Ramblas, rising to a second and third mezzanine level under the ridge of the side aisles. The architect was able to take advantage of the protected interior location, which meant there were no issues with overheating due to the sun, and the design pavilions could comfortably employ highly glazed facades.
The architect chose to detail most of the doors and windows as part of the bespoke pavilion design rather than specifying an existing product. This was because it felt that wood lent itself more easily to the custom dimensions and designs of the mullions than aluminium or steel, and allowed it to co-ordinate the window dimensions with those of the 32cm by 32cm structural members – mullions are detailed as 9cm + 14cm shadow recess + 9cm mullion.
On the ground floor commercial units, double-glazed windows are framed in laminated European oak in bays measuring 3.6m high by 2.4m wide. Mullions are a chunky 9cm and 15-16cm deep. The oak is also used to form a first floor balustrade to balconies, and for staircases inside and out including pairs of crossing staircases over side streets between the pavilions. The double glass doors measure 2m by 1.20m.
A different approach was taken for the top two floors, where the mullions needed to be load-bearing. Here, the contractor proposed a Jansen steel system.
The CLT pavilion structures were manufactured in epicea by Züblin in Austria over 45 weeks. They were erected in 5-6 weeks, with a further six weeks installing the Dutch-made oak window and doors and eight weeks of technical installations. For both structure and windows, finding a supplier that could cope with such a volume was a challenge. In the case of the windows and doors in particular, it was important to find a single source of wood in order to maintain a consistency of appearance, since these elements play such a strong role in the visual identity of the pavilions.
The phased construction completed in November, and one of the pavilions is already operational as a co-working space. The gardens and artwork are also complete. All it needs now is the people, and they will surely, in time, come too, completing the station’s century-long journey from freight depot to white-collar workplace and public space.
Architect Neutelings Riedijk Architects
Restoration architect Jan de Moffarts Architects, Bureau Bouwtechniek
Architectural engineering Bureau Bouwtechniek
Civil and structural engineering (renovation) Ney & Partners BXL
Civil and structural engineering (new pavilions) Ney & Partners WOW
MEP & building physics Boydens engineering, Brugge
Landscape architect OMGEVING
Main contractor MBG
CLT contractor Züblin
Windows contractor Webo
Installations contractor Cegelec, VMA, NTSA, Van Hoey, IFTech
Interior designer (public spaces) Neutelings Riedijk Architect
Artist (mosaics) Henri Jacobs