M62: a major restructuring combining construction requirements and ambitious usage plans, led by AG Real Estate France and GA Smart Building

Designed by Chevalier + Guillemot Architecture and carried out by GA Smart Building, the project involved a major restructuring, revealing the existing building's structural qualities while adapting it to new uses and environmental ambitions. With the original concrete structure preserved, the atrium enlarged, vertical circulation reconfigured, and steel joinery retained, the project embraced a technical, heritage-focused, and architectural approach.

The project's unique feature is its preserved, stripped-down, and exposed original concrete structure, whose monumentality becomes the foundation for the new architecture. The intervention also embraces the building's successive layers, including alterations and variations in materials resulting from its history, rather than erasing them. This frank interpretation of the existing structure establishes the identity of M62, giving the project its unique character.

At the heart of the project, the atrium underwent a major renovation. Enlarged from 7 x 8 m to 11 x 12 m, it reconfigures the circulation patterns, bringing more light into the heart of the building and structuring the entire structure around walkways and a monumental staircase. This reconfiguration was accompanied by extensive work on the building's core, including the renovation of one staircase, the creation of another, and the partial demolition and relocation of vertical circulation elements, in order to bring the building into compliance with current regulations, particularly those concerning public access buildings and fire safety.

The building is also distinguished by its attention to construction details. The design approach was to preserve as much as possible the elements that contribute to the building's character: the delicate exterior joinery and the historic steel frames, retained instead of more standardized aluminum solutions. This commitment is also reflected in the treatment of the interior spaces, where exposed beams, varying ceiling heights, and the raw materiality of the building become integral components of the design.

According to Arnaud Guennoc, Managing Director and Head of Development at AG Real Estate France: “M62 illustrates our approach to working with existing assets with high potential: preserving their identity, revealing their structural qualities, and managing their transformation with a high level of rigor. AG Real Estate France is accustomed to developing complex projects in dense urban areas (My Little Nation or 24Sentier), where mastering interfaces and site constraints is crucial.”

The environmental approach is evident in the decision to retain the core of the structure and building envelope, significantly reducing the project's carbon footprint. The project aims for BREEAM Excellent, WiredScore Gold, and OSMOZ certifications. It also incorporates a degree of reuse, particularly in lighting, increased green roofs, and expanded space dedicated to active transportation, in line with the objectives of the Paris bioclimatic Local Urban Development Plan (PLU). Furthermore, the renovation of the existing building saves approximately 150 kg CO2eq./m² compared to a new building compliant with the RE2020 standard.

For Olivier Guillemot, Associate Architect, Chevalier + Guillemot Architecture: “With M62, we sought to find a balance between the building's construction history and the uses it must now accommodate. The challenge was to restore coherence to the whole, embracing the diversity of eras, materials, and traces left by the site's various lives. It is this tension between permanence and adaptation that, in our opinion, gives the project its unique character.”

According to Gilles de Jouvencel, Managing Director of Renovated Real Estate at GA Smart Building: “In this context, our long-standing partnership with GA Smart Building is a real asset: we share the same high standards of execution, a common culture of handling complex operations, and a proven ability to jointly advance ambitious projects.” “M62 is a very concrete illustration of our expertise in renovation and rehabilitation: we are working on an existing building in the heart of the city, with extensive renovations in a demanding regulatory environment. This type of project requires high technical precision, flexibility in execution, and strong coordination among all project stakeholders. This restructuring also demonstrates our ability to provide competitive and flexible support to value-add operators, such as AG Real Estate France, who have trusted us for many years.”

Delivery is scheduled for the third quarter of 2026.

Technical specifications

• Project name: M62
• Nature of the operation: Major restructuring of an existing office building.
• Address: 62 rue Marcadet, 75018 Paris.
• Client: AG Real Estate France.
• General contractor: GA Smart Building.
• Technical lots: Klymeo.
• Area: 5,246 m2 - office building with 6 floors above ground.
• Existing heritage: Building inherited from the interwar period, reflecting a functionalist architecture.
• Architect behind the PC: François Larroche.
• Architect in charge of the PCM: Chevalier + Guillemot Architecture.
• Interior architecture: Antoine Ricardou – Ateliers Saint Lazare.
• Targeted certifications and labels: BREEAM Excellent, WiredScore GOLD level and OSMOZ label.