Immobilier tertiaire ZAC de la Chantrerie

Co-creating well-being: "Le Square" project in Nantes

Context: co-construction

In the north of Nantes, the ZAC de la Chantrerie has entered the 21st century by attracting high-tech companies, higher education institutions, and mixed-use developments. Spanning three hectares along the Erdre River, Le Square (15,600 m² floor area) is one of the flagship projects of this new urban dynamic, combining innovation with a focus on workplace well-being. Designed to accommodate four entities of the Macif Group Imatech, Ima Protect, Macifin, and Macif Direct and their 1,000 employees, the project reflects the occupants’ involvement from the very beginning of the design process. “The tenants chose this site for its accessibility and its location at the edge between city and nature,” explains Delphine Ouvrard, Program Director at Bâti Nantes, developer and project owner.

AIA Architectes responded with a design structured around three buildings (in addition to the car park) one for offices and two for the restaurant and gym all fully glazed and directly connected to the landscaped surroundings.

Challenges: enhancing workplace well-being

Views and natural light key factors in workplace quality of life guided the organization of spaces. A large central corridor divides the main office building, with a linear volume facing the street and fan-shaped blocks facing the park to maximize views. Open-plan floors of approximately 300 m² accommodate “tribes” of 36 employees a key feature of the program.

Built with a metal frame and structure, the 8,360 m² of WICONA aluminium façades “fade away in favor of the interior experience,” says François Renaudineau of AIA Architectes. Each floor is glazed on three sides; clerestory windows bring light into the central corridor; and the curved façades of “Le Bosquet” a twin building echoing the form of a grove traversed by a pathway open the restaurant and gym directly onto the surrounding park. To make the most of these daylight-filled spaces, specific measures were implemented to optimize thermal comfort sun protection on the office building and extended green roofs on “Le Bosquet.”

WICONA Solutions: comfort and light

The WICTEC 50 curtain wall system proved to be the ideal choice. “The system is easy to install and met the project’s seismic requirements,” notes Hervé Galindo, Project Manager at Arcalia. Incorporating solar-control glazing and, for the guardrail effect, safety glass on the office building (H. 11.5 m) the system also adapts perfectly to the faceted façade of “Le Bosquet” (H. 3.60 m). It integrates seamlessly with WICLINE 65 concealed-sash windows and WICSTYLE 65 doors. The pearl grey (RAL 7035) finish blends subtly into the background of the white solar shades and horizontal bands created by Arcalia to conceal the mechanisms of the motorized adjustable louvers.

A specific technical detail: at the architect’s request, Arcalia carried out acoustic insulation by inserting polyurethane foam into the curtain wall mullions located along modular partitions, preventing any resonance in the open-plan offices.

Benefits: success on every level

“From tenants to company executives who signed the contracts, all parties embraced the project’s philosophy and collaborative approach from the outset,” says Delphine Ouvrard. This collaborative method was reinforced by Bâti Nantes and the tenants’ participation in the local Association Foncière Urbaine Libre (AFUL). “For a project of this scale, the challenge was significant.” Mission accomplished.