In Les Fabriques, our team designs a regional headquarters for RTE at the cutting edge of energy sobriety

Located at the northern end of the Euroméditerranée extension, within the Phare block, the RTE project involves the construction of a 13,100 m² bioclimatic tertiary building designed to bring together more than 500 regional employees currently dispersed over the three sites in Marseille and Aix-en-Provence of the French public electricity transmission network operator. The eight-story regional headquarters includes office space, living and communication areas (lobby, company restaurant, showroom, recreation room, village square), a partially underground parking lot on two levels, a bicycle room on the first floor, a garden and large green terraces.

A singular, luminous and protective structure

Perfectly blended into its environment, the building is a geological emergence that integrates all the constraints and assets of the site where it is located. Thus, the strong duality between the avenue du Cap Pinède and the rue de Lyon at the intersection of which the building is designed deeply inspires its morphology. Taking advantage of the width of the avenue du Cap Pinède and its strong exposure to the Mistral, it is here that the building is tallest and takes on the most scope. It rises to eight levels and forms a first slope culminating at 30 meters preserving the heart of the block from the exhausting Mediterranean wind. Perpendicular to the rue de Lyon, it slopes down slightly and offers large accessible and protected roof terraces. Thus, the two street-side facades of the building can be compared to the steep slopes of a mountain, while the heart of the block, sheltered behind the northern wall, is like the restanques and valleys of the Mediterranean: protected from the wind, bathed in sunshine and coolness. This preserved interiority allows for outdoor work as well as collective activities. Between these two ambiences, activities, access spaces and other meeting and distribution areas are nestled.

In keeping with the idea of creating a dialogue between the project and the Mediterranean landscape through a protective architecture conducive to the well-being of employees, the façades, carved in light gray concrete, reflect a geological imagination that brings to mind the limestone resurgences of the hills in Marseille. Treated with sobriety by multiple perforations chiseled and jagged in a rhythm of full and empty spaces, they play with the sun while providing a large amount of light to the premises they house.

An ambitious environmental design

The Kardham Architecture teams, in partnership with Vincent Lavergne Architecte Urbaniste, have imagined a building offering solutions at the cutting edge of energy sobriety and resource optimization and aiming for the highest professional certifications.

The building's volume and layout seek to take advantage of natural elements, such as sunlight. The heart of the block is protected from the mistral by the north façade, while the patio, balconies and details of joinery allow a quality treatment of the requirements of luminosity, acoustics, ventilation and thermal. The project is also integrated into the Massiléo Urban Heating Network, a heating and cooling network powered by the calories of seawater, and includes the implementation of photovoltaic panels.

In addition, the project aims to achieve the BiodiverCity Ready label, which aims to integrate a new relationship with nature, particularly in the city, vegetation and living things into the act of building. This is why it includes as much vegetation as possible, in order to take maximum advantage of the coolness linked to the evapotranspiration of plants, unmatched by air conditioning systems. The site design provides for a fertile heart of the block, mostly in the open ground, with all plantings in the continuity of the Mediterranean plant palette, in order to meet ecological continuities.

In addition, water management by buffering on the terrace allows for the regulation of southern rains and the nourishment of the plantations. A landscaped ditch allows water to be retained to water the vegetation when rainfall is scarce.

The building is also aiming for HQE - Sustainable Building 2016 certification, with an EXCELLENT level of evaluation in terms of quality of life, respect for the environment, economic performance and responsible management.

Finally, the project is committed to the following requirements :

• BBio<BBio_max-40%,
• Cep<Cep_max-40%.
• 2-star accessibility label
• ENERGY - CARBON label at E2C1 level
• "Biosourced building" label, level 1
• Jardins de Noé Charter, Local Vegetable Label

Offices that promote synergies and cooperation between employees

The workspaces have been designed to be spread out around a patio on two levels and through large, modular floor plans, which will minimize the division by department and thus offer great freedom of organization and functional scalability. These floors open onto balconies on the south side, ideal spaces for developing open-space areas, as well as conviviality areas conducive to exchanges. For greater comfort in living and viewing, the construction system of load-bearing facades and long-span alveolar slabs will free the floors from cumbersome structural elements. Finally, several terraces accessible to the north act as true extensions of the interior surfaces and complete the possibilities of appropriation of the exterior spaces by the users.

Still in terms of space design, Kardham will accompany RTE teams on various missions: co-design workshops to define work and service spaces with their future users, macro and microzoning modules, interior architecture concept; or even furniture support mission.

With this new building, RTE hopes to demonstrate its public service vocation and its sustainable commitment to respecting the environment and improving the quality of life at work in the Mediterranean region.

TECHNICAL INFORMATIONS

• Project Owner : RTE Réseau de Transport d’Electricité
• Promoteurs : Linkcity et Bouygues Immobilier
• Partners : Vincent Lavergne Architecture et Urbanisme, Hélène Pépin paysagiste, Bouygues Bâtiment Sud-Est, Lasa, Aveltys, AC2R, CCE Ingénierie, Projex
• Mission : Maitrise d’œuvre de conception et d’exécution + space planning/Aménagement
• Delivery : 2025
• Environmental quality : Label E+C-Label biosourcé, Label HQE bâtiment durable, Label Biodiversity Ready
• BIM Management