The Kardham Group will design IRSN's new bioclimatic tertiary building

Installed on the site of the Atomic Energy Commission (CEA) of Cadarache in Saint-Paul-lez-Durance in Provence-Alpes Côte d'Azur, this building is distinguished by its bioclimatic and HQE architecture, so as to integrate in a respected environment and offer a high quality working environment.

Intended to bring together the IRSN teams with the aim of improving performance and modernizing its building stock, the future building, made up of two wings, will have an area of ​​around 5.400 m² (SDP), spread over 4 levels including 1 semi- buried.

A building that dialogues with the landscape

Kardham's teams first paid particular attention to adapting the project to the topography, climate and geography of the host site, the CEA in Cadarache, the largest research and development center in Europe for low-carbon energies. .

The construction is thus integrated into a pine forest made up of maritime pines 8 to 12 meters high, preserved as much as possible and which will serve as a green setting for the IRSN site. The elevations of the roads and car parks will also be adapted to the pine forest to preserve the existing subjects.

To respect the topography of the site, Kardham also opted for differences in levels to create a raised forecourt, a balcony terrace, or even bleachers in an embankment forming a natural amphitheater. By limiting as much as possible the height of the building in R+2, the overall volume fits into this exceptional wooded site and is on the scale of the other constructions on the site.

The shapes have also been designed and the colors chosen to blend into the landscape: the plinth, in rust-coloured cladding, picks up the vibration and the language of the ground, in dialogue with this Mediterranean landscape made up of pine needles, rockery, while the upper parts of the building come to discuss with the pines and the canopy of trees. The vertical lines take up the inclinations of the trunks and join the cast shadows and multiple lineages. The brise-soleils evoke the foliage in the trees in order to reinforce the vibration of the boxes.

Sustainable and frugal construction

The building has been eco-designed to meet strong expectations in terms of reducing its carbon footprint.

First of all, from the point of view of the choice of materials, it testifies to a remarkable constructive biodiversity: the structure, the facades and the slabs of the building are made of reinforced concrete. The glazed frames are made of aluminum and blend into the large glazed openings in the shade of the sunshades. All the construction and fittings materials used, wood, glass, vegetation, etc. are natural and organic materials.

The building also aims to be well thought out in its orientation and in its use of the sun and the winds, to require as little equipment as possible to maintain, heat or cool it. Thus, for the sake of operating savings and the means of implementing solar protection, the North/South orientation has been favoured.

Finally, the construction is aiming for HQE “Sustainable Building” certification, excellent level, E3 C1 label as well as a commitment to control energy consumption, in accordance with the requirements of the France Relance plan.

A building conducive to exchanges and synergies

The architectural composition of the building is based on the organization of the functions it houses:

• A base grouping the services related to the delivery areas.
• A crossing horizontal opening on the outdoor spaces of the ground floor, creating an in-between welcoming shared services and reception.
• The suspended volumes floating in the pine forest accommodate the offices of the research services.

The building has also been designed to offer strong centralities, real centers of exchange and conviviality:

• In the center of the building, at the intersection of its 2 wings, an open-plan staircase in the form of a vertical through gap open to the outside, creates a link between the different departments.
• Floor polarities around common spaces: at the right of this vertical fault are grouped at each level the different common floor functions: coffee area, open archives, modular meeting space, shared work spaces, sanitary facilities. Privileged space of the building, this fault also benefits from a through opening on the pine forest on both sides of the building.
• Friendly exteriors in connection with the shared services on the ground floor: to their north, an entrance forecourt offers a large shaded space for exchanges, while to their south a large terrace offers a common outdoor space accessible from the entrance. Finally, at each gable, the stairs are extended by terraces that open up shared spaces to the outside.

This user-friendly centrality of the IRSN offices also exists in its strong connection with the various buildings on the site. The entrance hall makes it easy to serve them. In addition, the traffic lanes optimally connect the outdoor parking spaces to the existing buildings. Comfortable pedestrian paths complete the mesh of the site.

Modular workspaces co-designed with employees

The workspaces combine work of reflection and confidentiality with collaborative work. These common places, meeting, exchange and conviviality, workstations open or isolated in cocoons or behind claustras intimidating the space, are moreover flexible and in particular equipped with partitions to follow the evolution of the needs of the services. For greater modularity, these spaces also benefit from direct natural lighting and large areas in the center of the building.

In terms of space design, Kardham will support IRSN employees through numerous workshops and interviews to allow them to project themselves into the functional programming and express their expectations and needs in terms of the layout of workspaces and local collaborative spaces. Thanks to these co-design modules, they will be able to consider the different scenarios for the positioning of common spaces, space typologies and workstations. The opportunity also to move from the individual dimension to that of the team, and to discover the workspace as a whole.

In the end, the project was designed to meet strong challenges in terms of sustainable development and is part of an intelligent and benevolent logic of respect for the environment and a greater quality of life at work.