raum architects completes 'block 5B' mixed-use building in nantes

BLOCK 5B AND THE CITY

raum architects prioritizes a dialogue with the city for this mixed-use project in nantes, france. called ‘block 5B’, the complex spans a total floor area of 23,555 sqm and comprises housing, offices, and public car parking.

situated near the train station, block 5B completes the northern fringe of the city’s euronantes district. this neighborhood connects other key districts and contributes towards the development of the western île de nantes by extension. the new architectural intervention aims not to connect to the metropolitan center, but to build the missing pieces of the city by being a center.

images by charles bouchaïb

the dialogue between block 5B and the city takes place at different scales: at large territory level, increased by the connection to the european rail network, at street level, and at neighborhood level.

block 5B is therefore conceived as a connection tool between the proposed uses and the wider landscape. to achieve this, the architects faced three main challenges: integrating a human scale, creating architecture with longevity, and designing for programmatic diversity.

the car park roof is topped with light roof constructions in the form of greenhouses and prefabricated timber structures

an architecture of paths

to establish a human scale within the urban landscape, raum architects considered the porosity of the ground floor level, paths, and hodology, which is the study of pathways. interpreted for this project, the design team inserted a large staircase between the curved corners of the office block and the public car park block. this wide staircase offers public access from the street to the roof, and to the different car park levels.

the car park block, cast in colored concrete

the city material

the second element of the design considers volumetry and materiality. the different functions—office, car park, and housing—are separated in form and size but connected by the elevational treatment.

the parking facilities are characterized by an exoskeleton of cast colored concrete and rough concrete floors inside. meanwhile, the residential and office volumes, which houses the SNCF réseau offices and workshops, are clad in terracotta brick.

the large public staircase divides the SNCF réseau offices to the left and the public car park on the right

coherent heterogeneity

the final aspect of block 5B looks at establishing programmatic diversity and clearly separating the entities to guarantee their modularity and promote exchange between them. according to raum architects, making the volumes distinct from one another offers the possibility of a real mutually beneficial neighborhood situation, favoring the mix and hybridization of uses. this division means the SNCF offices were completed before the rest of the building and the housing construction was phased independently from the car park phase.

the architects say, ‘the intrinsic quality of each fragment, linked to the possibility of autonomous operations, allowed the development of a simple project with an image in nantes station of foundations: an adaptation consistent with the neighborhood, using noble and long-lasting raw material as well as a mix of uses offering an intimate relationship between humans and the urban landscape of nantes.’

close-up view of the brick as it wraps around the office block

the parking facilities also feature a public roof garden

the mass colored concrete exoskeleton contrasts with the rough concrete floors

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project info:

name: block 5B

location: nantes, france
architecture: raum architects

all trade: egis

landscape: d’Ici là

acoustics: serdB

manufacturers: ID verde (exterior fittings), léon grosse (structural works), BYN / lucas reha (brick façades), smac / soprema (watertightness), CMBS / briand (carpentry work), claude (roofing), renouard / m atlantique / provetec (external carpentry), brault (ironwork), sati (drywall, insulation lining, ceilings), lilian (suspended ceilings), comey (false floors), AMH / dupré (internal carpentry), rossi (floor coverings, earthenware tiles), volume et couleurs / PPRV (paint), kone / schindler (lift), groupe FEE (plumbing, heating, ventilation), engie ineo / enelat (electricity, low current), def ouest (ieag)

construction work: nantes métropole aménagement and OCDL groupe giboire

budget: €22,120,000 EUROS (excluding tax)
surface area: 23,555 sqm (GFA), 3,470 sqm (living accommodation)
year: 2021